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Magazine of the Earth Science Ireland (ESI) Group ISSN 1753-5271

EARTH SCIENCEIreland www.earthscienceireland.org Issue 16 Winter 2014

IN THIS ISSUE:Fogo Island; Scrabo Country; Tale of Two Magmas; Groundwater Protection; Connemara Ice and Granite; Portrush Theft; Rock Detectives; Gold Rush; South African Researchers.And more ….

EDITORIALGeologists get around the world, as

some of the articles in this issue

demonstrate. There is a remarkable

story of a Cork man who headed out to

Canada as a bricklayer and returned as

a mining mogul. Other articles show how

people from this island have influenced

the development of our science abroad,

from the sphere of commercial to that of

academia.

There are articles to challenge the

readers and others that simply show the

fun of our science. Public service work

is reported as is academic research

but I must mention the private sector,

industry. Mostly from the ground this

provides the material to build roads and

houses, the minerals to make machinery

and computers, and the energy to

heat our homes and drive our cars.

We will continue to seek out reports

on ‘practical’ geology - potentially the

backbone of any country..

I thank again the authors who share

with us their excitement about the Earth

we live on. As we reach even to comets

so there remains so much we don’t

understand about the ground we stand

on.

Apologies for the late production of

this issue – it is hoped we get back

on schedule next April. Please let your

editors know what you think; we will

listen and when appropriate will publish

your comments ◼

Acknowledgements

Without generous sponsorship the

magazine, now in its 14th year, would

not exist. Thank you: The Northern

Ireland Environment Agency; The

Geological Survey of Northern Ireland;

The Geological Survey of Ireland. Also

The National Museum & Galleries of

Northern Ireland; The National Museum

of Ireland; The Royal Irish Academy; The

Belfast Geologists’ Society; The Cork

Geological Association; The Galway

Geological Association.

The views expressed in the magazine

are those of the authors. All rights

reserved. Permission to reproduce, copy

or transmit all or part of the publication

must be obtained from the Editor.

■ Tony Bazley, Editor, Earth Science Ireland, 19 Inishanier, Killinchy, Newtownards, Co Down BT23 6SU Email: [email protected]

Earth Science Ireland – raising awareness of Earth science across Ireland

Chairperson: Marie Cowan; Secretary: Robbie Meehan, email;[email protected] Treasurer: Joanne Curran;

Magazine - Editor-in-Chief: Tony Bazley; Editors: Bernard Anderson, Robbie Meehan.

Committee Members: John Arthurs, Bob Dickey, Garth Earls, Ian Enlander, Martin Feely, Enda Gallagher, Sarah Gatley,

Mairéad Glennon, Bettie Higgs, David Kirk, Kirstin Lemon, Barry Long, Paul Lyle, William Lynn, Patrick McKeever, Jenny

McKinley, Ian Meighan, Matthew Parkes, Karen Parks, Sophie Préteseille, Alastair Ruffell, Michael Simms

Earth Science Ireland is published by the ESI Group, Belfast. It is printed and designed by DORMAN & SONS LTD, Unit 2,

2A Apollo Road, Boucher Road, Belfast BT12 6HP; Tel: 028 9066 6700.

Cover photographRock detectives standing on the evidence

Magazine of the Earth Science Ireland (ESI) Group ISSN 1753-5271

EARTH SCIENCEIreland www.earthscienceireland.org

Issue 16 Winter 2014

IN THIS ISSUE:

??And more ….

ENQUIRY FILES 6In this series in the magazine in each issue we can highlight some of the oddities of the geological world, brought to light by ordinary people in their lives and travels, and brought into museum curators for identification.

“Knobbly object”

The Inventory Project nearing completion in the National Museum of Ireland has a habit of throwing up some odd things in drawers. One such object included (somewhat doubtfully) with archaeological collections from Carrowmore in Sligo was given to me to identify.

The object is about 14 cm long and crudely symmetrical around a slight constricted band mid-length. Each side has 4 points at an angle less than perpendicular and one central longitudinal point. Each point is of variable width and length and ‘pointiness’. The material itself is broken on one point so an internal

surface is visible and it appears to be a fine to medium grained sandstone with poor sorting as a few grains are large, and may be rock fragments rather than quartz.

So it would seem to be an entirely natural object, with no sculpting into shape by human hand. I have not seen a nodule or concretion of this shape before and wonder if readers have any notion of where it might be from and how it was formed? It has beaten this curator, does it beat you?

Matthew Parkes ([email protected]) ◼

Earth Science Ireland Magazine2

ROCK DETECTIVESKirstin Lemon explainsHelping to nurture the next generation

of geologists, the Rock Detective Club

was launched at the end of August at the

Marble Arch Caves Global Geopark, in Co.

Fermanagh and Co. Cavan. Established

as part of the Border Uplands Project,

and organized by the Geological Survey

of Northern Ireland, this kids-only

geology club aims to encourage children

aged between 4 and 12 years old to

discover and, more importantly, to be

excited about the rocks and landscapes

in their local area.

Four events took place over the last two

weekends in August, with the first two

held in the newly opened Cavan Burren

Park and at the Marble Arch Caves.

In addition, two events were organized

for the surrounding counties of Leitrim

and Sligo with the goal of providing an

opportunity to understand the shared

geological heritage of the entire Border

Uplands region.

There was a wide variety of themes

covered over the two weekends

including limestone and caves, geology

and archaeology, mining heritage, and

Carboniferous fossils. Each topic was

introduced using a number of messy

hands-on activities and often included

a mini field trip giving the children the

chance to try out their new ‘detective’

skills.

Many hands-on activities

Some of the activities that were carried

out included exploding volcanoes,

making your own planet Earth, digging in

glacial sand, fossil making, and finding

out exactly what it was like to be a

miner. There were also treasure hunts,

fossil quests, story telling, and virtual

cave exploration; all combined to tell the

fascinating geological story of the entire

Border Uplands region.

In total, just fewer than 200 children

attended the Rock Detectives Clubs and

due to the extremely positive feedback,

these will continue to run in the future.

They will hopefully inspire a number of

budding young Earth scientists.

The Border Uplands Project is a cross-

border, tourism development project,

which is funded ender the European

Union’s INTERREG IVA programme

and managed by the Special European

Union’s Programme Body (SEUPB).

The Lead Partner is the Irish Central

Border Area Network (ICBAN) and will

be delivered through close cooperation

between Cavan County Council,

Fermanagh District Council, Sligo County

Council and Leitrim Council.

The aim of the Border Uplands Project

is to increase the geo-tourism and

recreational potential of the region,

having significant economic and social

benefits for rural development. ◼

'Rock detectives' studying a case in Sligo

Issue 15 3

FLUORESCENT MINERALS & UV LIGHTBy George ReynoldsAlthough many people collect minerals, the public is generally unaware of the beautiful colours of fluorescent minerals under ultraviolet light. A small investment in a UV lamp opens up a whole new world in mineral collecting. The investigation of fluorescent minerals has given rise to many advances in physics and chemistry which we take for granted nowadays. Fluorescent minerals and compounds have allowed us to visualise otherwise invisible radiation like x-rays and ultra-violet light.

Fluorescence usually refers to the visible light obtained when a fluorescent substance or phosphor is illuminated with light of a shorter wavelength, usually ultra-violet light. This has nothing to do with the element phosphorous which oxidises in air emitting visible light. Normally fluorescence ceases when the illumination is turned off although some materials show a short-lived persistence termed phosphorescence, useful in early radar screens to leave a trail. The term luminescence refers to all light produced by fluorescence, phosphorescence, bio- and chemi-luminescence, and which is not produced by a high-temperature incandescent source like a tungsten filament lamp.

Ultra-violet (“UV”) light:

The visible spectrum ranges from red light at 700 nm wavelength (1 nanometre is one-millionth of a millimetre) to violet light at 400 nm. The ultraviolet band is divided into three bands, UVA (400-350nm), which passes through most glass and plastic with some absorption; UVB (350-300nm); and UVC (300-200nm). Both UVB and UVC are blocked by most types of glass except quartz

glass. UVA has little biological effect but UVB and UVC cause suntan and sunburn and have germicidal properties.

For mineralogical purpose a simpler division is into longwave (400–315nm) and shortwave (315-200nm). Although there is always a small amount of visible light emitted, UV light itself is invisible, so it is impossible to appreciate the intensity. It is never advisable to look into any lamp, even a longwave lamp.

When UV light photons are absorbed by a fluorescent mineral or synthetic phosphor, some electrons are boosted up to higher energy levels before falling back and emitting light of longer wavelength. A delay in this process gives rise to the persistence of the fluorescence. The difference in wavelength between the absorbed and emitted light is called the Stokes shift. Fluorescence is activated by trace quantities of certain elements such as lead, manganese, molybdenum, uranium or some rare-earth element like cerium or europium in the atomic lattice of the mineral crystal. The presence of other elements such as iron or copper can quench this fluorescence.

Examples of fluorescence:

Fluorescence is useful in mineral exploration. Scheelite is a tungsten mineral which is difficult to distinguish from feldspars. Under short-wave UVC (254nm) it fluoresces a diagnostic blue-white giving no result with longwave UV. Many uranium minerals fluoresce a green or yellow colour under long wave UVA (365 nm). Other items which fluoresce include high-visibility jackets and labels, tonic water (bluish-

white), scorpions (green) and even some body fluids, as well as the bright white fluorescent additive used in washing powder to make those whites “whiter than white”. Vitamin B2 or Riboflavin (E-101) is excreted from the body and causes an orange fluorescence in urine, especially if one is taking this as a vitamin additive. UV lamps can be used to screen children for ringworm as the fungus fluoresces brightly.

Fluorescent paints of all colours are now more widely available than ever and find many uses in theatrical and special effects. Fluoroscein dyes are used as tracers in hydrogeology and in leak detection in automotive and aircraft engine repair as well as in DNA processing and microbiology. Finally, postal sorting

UV and Visible light spectrum

Portable 6-watt UV lamp


uses fluorescent dots with varying persistence times, and clear fluorescent ink is used for security marking.

Phosphors:

In the 19th century fluorescent materials such as zinc sulphide derived from minerals were used to reveal the presence of X-rays, electron beams and alpha particles and led to the development of phosphors, exotic chemical compounds which can fluoresce in various colours and are widely used in cathode-ray tubes (CRTs), monitors, radar and TV screens. Modern phosphors are based around alkali metal halides and transition element metal oxides and sulphides, doped with trace amounts of activators such as silver, manganese, thallium, zinc and the rare earth elements such as cerium, terbium and europium.

The long-persistence green phosphor used in compasses and security signage is strontium aluminate activated by europium, which has replaced the bismuth-activated cadmium sulphide used in those older alarm clocks with a rather useless persistence of about ten minutes or so. Gone too are the older radio-luminescent paints of zinc sulphide phosphors mixed with radium sulphate, notorious for their propensity to crumble into a contaminating radioactive dust.

Fluorescent minerals:

Scheelite (CaWO4) an important tungsten mineral is found near Aughrim (Wicklow) and can be observed in concentrates from panning for gold in the streams of the region. Autunite (Ca(UO2)2(PO4)2) a secondary uranium mineral can be seen as pearly green flecks in outcrop in the Barnesmore granite (Donegal), but it is rare to find larger samples of either for collections. Many collectors prefer to buy samples from mineral suppliers. Many of these come from the Franklin mine in New Jersey, just one hour’s drive from New York. This is a famous location for

rare zinc, iron and manganese minerals in the old mines now closed since 1986. These mines produced over 300 species of fluorescent minerals with greater variety than any other location. The classic mineral assemblage from Franklin includes willemite (Zn2SiO4), zincite (ZnO) and franklinite (ZnFe2O4), However it is the willemite and the associated calcite that give rise to the popular fluorescent samples, fluorescing a vivid green and red respectively.

The intense red fluorescence of calcite from Franklin and other localities is caused by a manganese and/or lead activator which must be present in an amount of 1% to 5%. More or less than this amount will result in no fluorescence at all. The amount of an activator is as important as the type and calcite can fluoresce in almost any colour. Some calcite samples display significant phosphorescence also. Calcite is a common mineral in Ireland and specimens are know to be fluorescent from certain localities. This should be an incentive for collectors to check out known calcite occurrences and perhaps discover new fluorescent varieties and localities.

UV lamps:

All incandescent lamps, like sunlight, produce some UV content but the predominant visible light has to be filtered out, causing the filter to get very hot. “Blacklight” lamps, popular in the 60s and good for theatrical effects emit too much blue-violet light to allow delicate fluorescence from minerals to be observed. LED UV torches also emit too much blue light, as do lamps for checking banknotes. Only a quartz tube mercury-vapour lamp with a neodymium oxide or “Woods glass” filter can be used for mineral prospecting. Unfortunately this makes them somewhat expensive.

Electron energy levels

Autunite - a uranium phosphate mineral

Calcite (red) and fluorite under daylight and UV

Issue 15 5

If you don’t mind not observing the shortwave fluorescence of scheelite, a good 4-watt longwave lamp will have a higher intensity and cost less than its more heavily-filtered shortwave version and will work well with most fluorescent minerals. A multi-wavelength (SW+LW) lamp is even better, but as some minerals fluoresce in different colours under SW and LW, this type of lamp will not permit both colours to be observed separately. UV lamps are available in portable and main-powered versions, costing from about €40 to €300.

A dual wavelength (SW/LW) lamp is the choice of the professional but is more expensive and will have somewhat lower output than a “mono” wavelength, SW or LW lamp, as a slider is used to cover alternate half of the tube. Higher-powered 8-20W laboratory lamps are also available as well as observation and display cabinets. Over time, the filters will eventually “solarise” and become somewhat opaque to the UV, reducing the output and requiring replacement.

Fluorescent mineral collections:

Ulster Museum, Belfast

Geology Museums: TCD, NUIG, UCC

Royal Belgian Institute of Natural

Sciences, Brussels

Natural History Museum, Lausanne

Maison des Minéraux, Crozon, Brittany

UV Products (Agent):

Davidson & Hardy (Lab. Supplies) Ltd.

453-459 Antrim Road Belfast BT15 3BL

& 8 Pembroke Road Dublin 4.

Fluorescent Mineral Suppliers :

Causeway Minerals; Trevor Boyd, Co.

Antrim “causewayminerals.co.uk”

Miners Incorporated; PO Box 1301,

689 Old Pollock Road, Riggins, ID

83549

Veronica Matthews Minerals; PO Box

588 Westbrook, CT 06498

Geoscience Industries; Fort Collins

225 Smokey St. Dept. Ft. Collins, CO

80525

Mama’s Minerals Inc., 1100 San Mateo

Blvd. NE, Suite 15, Albuquerque, NM

87110

Typical longwave minerals: Calcite: red; blue (Hg-activator), yellow

Willemite: green

Fluorite: blue; green; red

Chalcedony: green

Sodalite: orange-yellow

Typical shortwave minerals Scheelite: blue-white only under SW

Agrellite: pink

Aragonite: green; pink, red; white-

cream

Norbergite : yellow-orange ◼

Scorpions are fluorescent

Scheelite (Causeway Minerals)

Fluorite (Causeway Minerals)


The National Groundwater Protection Scheme 2014 Monica Lee, Groundwater Section, Geological Survey of Ireland, explainsIntroduction

Over the last few decades, there has been increasing recognition and awareness of groundwater and groundwater protection, especially with the advent of the Water Framework Directive (WFD). Groundwater is a significant natural resource that currently supplies an estimated 20-25% of drinking water in Ireland, with the potential to supply more. Additionally, it can provide significant contributions to wetlands and rivers, with an especially important role of maintaining flows through dry periods.

Groundwater in Ireland is protected under European Community and national legislation. The responsibility for enforcing the legislation resides with the local authorities/Irish Water and the Environmental Protection Agency (EPA). A vital element in groundwater protection is the use of relevant maps to make risk-based decisions. These maps and allied decision-making tools are provided in the Groundwater Protection Schemes (GWPS).

How a Groundwater Protection Scheme Works

As shown in Figure 1, there are two main components of a groundwater protection

scheme:

• Land surface zoning: this provides the general framework for a GWPS and is a map that divides the area into a number of groundwater protection zones according to the degree of protection required.

• Groundwater protection response matrices for potentially polluting activities: gives guidance on the locating a specific, potentially polluting activity, depending on which groundwater protection zone the activity is (planned to be) in. The matrices describe: (i) the degree of acceptability of the activity; (ii) the conditions to be applied; and, in some instances (iii) the investigations that may be necessary prior to decision-making.

Figure 1 shows the three mapped hydrogeological elements to land surface zoning:

• Groundwater Vulnerability Map: Division of the entire land surface according to the vulnerability of the underlying groundwater to contamination.

• Aquifer Map: Delineation of areas

according to the value of the groundwater resources.

• Groundwater Source Protection Area Map: Delineation of areas surrounding groundwater sources (usually public supply sources).

• These three elements are integrated together to give maps showing groundwater protection zones.

Development of Groundwater Protection Schemes (GWPS)

GWPS have been developing ever since their inception in the mid-1980s. The underlying framework is based on a number of applicable, international methods used in countries with similar geology and hydrogeology. It also, though, incorporates the results of Irish groundwater protection research. GWPS focus on Irish water quality issues and potential sources of contamination, whilst being robust enough to adapt to emerging issues. The Groundwater Protection Schemes booklet1 was launched in 1999 as a joint document between the Geological Survey of

1 ‘Groundwater Protection Schemes’ (DoELG/EPA/GSI, 1999): http://www.gsi.ie/Programmes/Groundwater/Projects/Groundwater+Protection+Schemes.htm.

Figure 1. Summary of Components of a Groundwater Protection Scheme

Issue 15 7

Ireland (GSI), EPA and Department for the Environment, Community and Local Government2.

During the mid-1990s, the GWPS land surface zoning maps were produced on a county-basis as projects funded jointly by the GSI and the respective Local Authority (who bore approximately 70% of the cost). For these schemes, all three elements – groundwater vulnerability, aquifer, source protection areas – were mapped, assessed, and then combined on a county basis.

Throughout the 2000s, the work of the Groundwater Section in the GSI was strongly influenced by the needs of the Water Framework Directive. The GSI embarked on the provision of a National Aquifer Map in order to characterise Irish groundwater and delineate the ‘Groundwater Body’ management units3. The National Aquifer Map was finalised in 2004.

During this period, the county GWPS were still being produced and by 2007, 15 counties had been completed. However, the first of these schemes were already considered to be of less use because they did not use the most up-to-date data or methodologies, nor were they available in the required digital, GIS formats (Counties Clare, Limerick, Offaly and Tipperary South).

In 2007, the GSI received Geoscience (National Development Plan) Funding. A portion of this was allocated to fund the Groundwater Vulnerability Mapping Programme. The main drivers were to provide the risk assessment layers for the Water Framework Directive characterisation work as well as provide

one of the key layers for the GWPS, which were required by the Local Authorities. As such, the Local Authorities also funded a proportion of the vulnerability mapping programme.

The 2007-2014 Groundwater Vulnerability Mapping and Groundwater Protection Scheme Programmes.

By late 2007, a schedule for a five year mapping programme had been established and a consultant mapping team acquired to undertaken work. The team comprised:

• Tobin Engineering Consultants:

• Coran Kelly: project manager;

• Monika Kabza, Orla Murphy and Melissa Spillane: mapping geologists;

• Dr. Robert Meehan: Quaternary specialist and supervisor (sub-contracted to Tobins).

• Peter Cooney: GIS consultant

This team worked with the GSI Groundwater Section staff (Taly Hunter Williams, Caoimhe Hickey and Monica Lee) as well as a large number of GSI geological assistants and interns over the entire period4.

The programme was ambitious, with 15 counties that required vulnerability mapping (see Table 1 and Figure 2a).

In order to successfully complete the map production, as well as documenting the data analyses and work that supported the vulnerability classification decisions, each year had a very busy and tight schedule. The work required:

Table 1. Counties Covered During Work Programme

Work Year Counties Area Covered (km2)

Year 1 (2008/2009) Dublin, Leitrim, Longford, Louth, Sligo, Westmeath 8,100

Year 2 (2009/2010) Carlow, Offaly, Limerick, Waterford, Wexford 9,900

Year 3 (2010/2011) Mayo, Tipperary 9,900

Year 4 (2011/2012) Cork (north and west), Kerry 9,800

Year 5 (2012/2013)Re-mapping: Clare, Donegal, Laois, Kilkenny, Wicklow, Galway-Roscommon border, Tipperary-Limerick border

13,000

Figure 2a. Areas in Each Mapping Year Figure 2b. Additional Mapping Areas

2 Formerly known as the Department for the Environment and Local Government.3 The National Aquifer Map is the fundamental layer used to delineate Groundwater Bodies, which are the groundwater management unit for the

Water Framework Directive. For more information, refer to (http://www.wfdireland.ie/Documents/Characterisation%20Report/Background%20Information/Analaysis%20of%20Characters/Groundwater/GW2%20Groundwater%20Body%20Delineation.pdf)

4 Natalia Fernández de Vera, Jutta Hoppe, Magdalena Runge, Elena Berges, Shane Carey, Declan Kavanagh, Ramon Aznar, Rory Westrup, John Carroll, Marek Urbanski, Axel Keess, Sara Raymond, Nicola Salviani.


• 3-6 months of data collection and processing by the interns;

• 6-7 months of fieldwork by the three mapping geologists (see Plate 1), which included a GSI drilling programme (to gather subsoil permeability and depth to bedrock data);

• 6-7 months of data interpretation and map compilation by the three mapping geologists;

• Continual GIS work and support from the GIS consultant;

• Substantial technical supervision and support from the project manager, Quaternary specialist and GSI staff.

• Outreach and administrative support by the GSI staff and some of the Tobin team.

Due to the success of the programme, the works were extended to re-map all or part of five additional counties (Shown in Figure 2b and Table 1: Year 5). Although these areas were previously available in an appropriate digital format, it was now apparent that the data and methodologies used were out-of-date and in order to produce a standardised national product, additional work would be required. Unlike the previous four years’ of first-time mapping and map compilation though, the work needed to be tailored to the specific needs of each county or area, which was both interesting and challenging.

Present Status, Usage and Future Work

The mapping, data analysis and map compilation work is now complete with resulting National Groundwater Vulnerability, Subsoil Permeability, and GWPS Maps available for use by organisations and individuals. All counties involved now have draft GWPSs to aid them in their work. The national Groundwater Vulnerability maps are being used for source protection work throughout the country as well as being a national data layer e.g. EPA assessments of high risk areas for domestic waste water treatment systems. They are also available for the next phase of WFD work.

The follow-on work in 2014 has included amendments to the National Groundwater Vulnerability and GWPS Maps where more recent data have become available, and to produce the accompanying documentation and reports that outline the methodology and data on which the classification decisions were made. These will be available by the end of the year.

In order to expedite the national GWPS map, the source protection work and certain elements of the vulnerability mapping were postponed e.g. countrywide karst feature mapping was not specifically addressed as this would have been too labour intensive for the available funding and timeframe. Furthermore, during this period, a number of relevant pieces of research and additional geological

mapping have been completed and there are the continuing advancements in the resolution of digitally available data.

To maintain the utility of the GSI maps, these features do need to be incorporated and addressed. The GSI have already embarked on a pilot study to address how karst features can be more efficiently mapped. Results will be available in the coming months. A map review process will be started to incorporate any new geological information. More fundamentally, given the increasing requirement for accurate, higher resolution information, mapping programmes at more local scales are currently being developed.

In summary, National Groundwater Protection Scheme and Groundwater Vulnerability Maps are now available. This is a huge achievement and it has taken over 20 years to get to this point. However, given the ever-increasing awareness of issues and data that are available, there are already improvements that can be made to provide better and more useful tools to meet environmental management needs.

For further information, please visit h t t p : //www.gs i . i e/P r og rammes/Groundwater, or contact the Groundwater Section. To view groundwater maps and datasets, visit http://spatial.dcenr.gov.ie/GeologicalSurvey/Groundwater/index.html or http://spatial.dcenr.gov.ie/imf/imf.jsp?site=Groundwater. ◼

Plate 1. Images from Field Mapping

ANNUAL IRISH GEOLOGICAL RESEARCH MEETINGBELFAST 20th – 22nd February 2015

The annual Irish Geological Research Meeting will take place in 2015 at the Ulster Museum in Belfast from 20th to 22nd February, co-organised by Mike Simms (National Museums of Northern Ireland), Marie Cowan and Mark Cooper (Geological Survey NI) and Jenny McKinley and Alastair Ruffell (Queen’s University Belfast). Keynote speakers this year will be Valentin

Troll (Uppsala) and Tori Herridge (Natural History Museum). Further details will be available through the organisers’ websites and elsewhere. ◼

Issue 15 9

This article salutes a second scientist who ventured into the marine realm and who did much to unravel the complexities of Ireland’s offshore geology.

Raymond Keary can be considered one of, if not the leading light in marine geological studies in Ireland at the end of the last century. Born in 1937 in Woodford, Co. Galway he was drawn to water and the ocean at an early age through his grandfather, who had a small boat, and father who was a doctor on Inishbofin. Educated at UCD he undertook post-graduate studies on the Leinster Granite – at this time he discovered the rare orbicular facies in a loose boulder. This texture was known from granites in Donegal but until Ray’s discovery not in plutons further south. Unfortunately to date no bedrock examples have come to light.

He returned westward in 1962 to take up a lecturing position in University College Galway where he remained for 13 years. In a visionary example of recruitment, Cyril Williams the Director of the Geological Survey of Ireland (GSI) asked him to set up and head a Marine Research unit.

Prior to his appointment not a great deal of time had been devoted to the study of marine geology in Ireland. In 1901 Grenville Cole of the Royal College of Science for Ireland and Thomas Crook had reported on rocks dredged from the depths of the Atlantic, and from the 1960s various multinational companies had surveyed and drilled parts of the seabed in their exploration for oil and gas. Of course the Admiralty had already mapped out large areas of the seabed,

and quite a number of expeditions since the glory days of H.M.S. Challenger had trawled and dredged the continental shelf primarily for biological specimens.

From 1975 Ray Keary undertook a number of surveys of the seabed utilising the vessel Lough Beltra, partially necessary given United Nations directives that required the definition of national marine boundaries. Initially he worked in the Irish Sea, but later developed the GLORIA programme of deeper-water reconaissance of the Porcupine and Rockall districts. This led to the funding of a comprehensive surveying programme; the Irish National Seabed Survey ran from 1999, just before Ray’s retirement, to its completion in 2005, just after his death two years earlier.

His scientific contributions were recognised by the conferring in April 2002 of a DSc from the National University of Ireland. He is commemorated by the research vessel Keary that was named in October 2009 and which sees extensive service in shallow-water surveys around Ireland.

There is a wealth of data now gathered on Ireland’s offshore. Recent and on-going surveys and initiatives such as the INFOMAR project, coordinated by the Geological Survey of Ireland and the Marine Institute, have yielded stunning results. Cool-water, deep-water coral reefs have been extensively mapped; submarine sediments, sampled for provenance studies, have provided data on the Tertiary denudation of Ireland; microfossils have helped to document sea-level and climatic fluctuations that have affected our island over the last few million years.

There is little doubt that Raymond Keary was a driving force in the opening up of marine science research in Ireland and one can successfully argue that such research would not have commenced without his vision. His own research on sediments and the nature of the seabed around Ireland is contained in reports and scientific papers. This, together with on-going marine research, is his continued legacy.

Further information is available in an online article by Enda Gallagher (http://www.gsiseabed.ie/ray.htm) and also online at http://infomar.ie/surveying/Keary/Keary.php

I am grateful to Patrick Roycroft for alerting me to Ray’s discovery of the Leinster orbicular granite, and to sources in the GSI. ◼

Irish ‘Rock Stars’Patrick Wyse Jackson, Trinity College Dublin, continues his series

Raymond Keary - (1937–2003)

Ray Keary at his retirement party (from GSI webpage)

R.V. Keary (from Infomar webpage)

ErratumIn the article ‘Sailing Away’ (Issue 15, p.8) your editor wrongly described Peter Crowther as a Curator and an Assistant Director. Kindly replying, Peter said how much he and Jill appreciated our good wishes for their life in Yorkshire. He did, however, put me right about his job titles. With apologies and to get the record straight:

Peter firstly came to Northern Ireland as Keeper of Geology at the Ulster Museum and later became Head of Natural Sciences for National Museums Northern Ireland.

R.A.B. ◼


Theft of precious fossils at Portrush and reflections on collecting.Ian Enlander, Northern Ireland Environment AgencyReaders may be aware of the recent illegal removal of fossil material from the Portrush National Nature Reserve. The site is of international importance for the part it played in the historical debate between the Vulcanist and Neptunist schools of thought in relation to the origins of igneous rocks.

What is so special about Portrush Rock?

In summary, rocks at this site were initially identified as basalts but containing a range of fossils, predominantly ammonites. Neptunists saw this as conclusive proof, supporting their view, that what we now regard as igneous rocks originated as precipitates within a primeval ocean. How, they argued, could life exist in such rocks if, as the Vulcanists stated, such rocks began life as molten magma? The controversial rocks at Portrush were of such significance in this debate that a number of the great geologists of the late 18th and early 19th centuries visited the site. Amongst these was John Playfair who correctly interpreted the rock as a thermally altered mudstone.

This Jurassic age mudstone, typically rich in fossils wherever it is found in Northern Ireland, was altered by contact with the much younger (Palaeogene) massive dolerite sill which was injected below the mudstones and baking them in the process. The sill forms Ramore Head on which Portrush has developed. This geological conflict was resolved through good observation of the field evidence. Some have gone so far as to say that the site is one of the most important geological sites in the world given its critical position in the Neptunist/Vulcanist debate combined with use of geological field skills to overturn a position that was, at least partially, one of dogma.

Further information on this debate and on the geology of this remarkable site can be found on the Earth Science Conservation Review website www.h a b i t a s . o r g . u k / e s c r / s u m m a r y.asp?item=60.

The site is now owned by the Department of the Environment. In addition to its designation as a National Nature Reserve it is also an Area of Special Scientific Interest. Collecting any geological material here is entirely prohibited with signage to that effect present.

Illegal removal of rock and fossils

Material was removed earlier this year with the collecting mainly limited to sections ironically shielded from wider view by the Department’s visitor facility, the Portrush Coastal Zone. This suggests that the person knew that collecting was illegal. It is not clear why the material was taken – the ammonites are not of particularly good quality – but the volume removed points to this being more than just a private collector. Collecting did not appear to be systematic (e.g. bed by bed sampling) so that probably rules out genuine research activity.

The Police Service of Northern Ireland has been informed and the Department’s Minister, Mark Durkan, is on record expressing his outrage at the incident.

So why worry about the loss of a few fossils? Apart from the fact that this is a ‘no collecting’ site, the accessible outcrop is very limited in extent and

already subject to natural coastal erosion so the last thing needed is extensive ad hoc collecting – it is not a locality that can sustain collecting. Fossiliferous sections can still be observed allowing visitors to understand more fully the historical debate, but many of the better ammonites are now gone.

Geological ASSIs and the geological community

The most scientifically important geological and geomorphological sites in Northern Ireland have been identified through the Departments Earth Science Conservation Review. Many of the sites have been designate by the Northern Ireland Environment Agency as Areas of Special Scientific Interest, a process that is still continuing. The intention of the designation is to ensure that owners are aware of the geological importance on their land and that site use, management activities or future developments do not adversely impact on the scientific interest, maintaining its importance for future generations.

In general NIEA encourage use of this series of geological sites for a range of activities including education and research where appropriate and where access is not an issue. However site sensitivities vary enormously and while

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there are a number of ASSIs where fossil collecting (or indeed mineral or rock collecting) is appropriate and can be viewed as sustainable, others are of such importance, highly vulnerable or limited in extent that collecting is prohibited or limited to bona fide researchers. Any collecting/sampling at these sites should only happen after consultation with the landowner and NIEA. Always ask yourself ‘Will a photograph do?’

Who owns the rocks and fossils?

There is no doubt that collecting is an essential part of geology. Our knowledge and indeed the research history behind the identification of Earth Science Conservation Review sites, depended on collecting. Critical analysis of our understanding of these sites in the context of a developing science also requires appropriate sampling. So in its place collecting is critical. And in appropriate locations, fossil collecting can be fun and a great means of engaging a wider public interest in

geology. Overall however, geologists, be they professional or amateurs, and others should consider carefully whether it is appropriate to collect and the purpose behind it.

Do we have a right to remove material? This is a somewhat ambiguous area in the context of Northern Ireland’s conservation legislation. There is a clear prohibition here on picking wildflowers without the consent of the landowner but no such specific legislation currently applies to our geological heritage. But it is generally the case that rocks, minerals and fossils form part of the land and so are treated in exactly the same manner as any other material forming or occurring on the land. We are removing someone else’s property when we collect – generally thought of as theft!

Best practice

There is no formal code to guide the collecting of geological materials in Northern Ireland but there is a good literature on the subject – see below.

Reading these I was surprised that the issue of permission is not more prominent so I would add the following to the standard guidance:

• Do you have permission to collect? Permission to access and collect generally has to come from the landowner.

• Do you need to collect? What purpose does this serve? Would photographs suffice?

Further reading

• Geological Association Geological Fieldwork Code www.geoconservation.com/GCCdocs/fieldworkcode.pdf

• JNCC Conserving Our Fossil Heritage - http://jncc.defra.gov.uk/page-4206

• Scottish Fossil Code - www.snh.org.uk/pdfs/fossil_code/fossilcode_08.pdf ◼

Ode to the erudite erraticsOn Burren’s limestone terraces lie alien boulders, granite crystals glinting. On Strangford’s wave smoothed sandstone shore fire-born dolerite giants in unease lie.

Just some - of all the earth’s erratics, lying lonely, torn far from their own, left lying and lost in a foreign land, strangers on unfamiliar beds.

Hear us, hear us, the spirits of the stones plead in timeless silence. We have such tales to tell, stories of how the earth was made.

But you must look deep to learn their tales, their stories must be seen, not heard. Don’t just look at us, see into us the erudite erratics plead.

Long journeys through endless times, across ever-changing lands; Sometimes worn to sand and dust, then reborn, as hard new rock again.

That’s just a load of cobbles, some might say. You want we should talk to rocks? But think again, remember - Stones are people too!

David Kirk ◼


A remarkable story!Mike McCarthy (15th October 1927 – 20th July 2014)

“He made a difference” is a claim that can be made by few men. Mike, a modest man, never made such a claim but we do it on his behalf and pay tribute.

Mike was born and raised on a farm in Mohonagh, Skibbereen, Co. Cork where his early years were marked by his interest in horse training and breeding, which he inherited from his father Jack.

In 1949, at the age of 22, he immigrated to Canada where he learnt his trade as a bricklayer and worked throughout western Canada on building projects. It was there that he met up with Pat Hughes, Joe McParland and Matt Gilroy. Together, these four would establish an industry in Ireland and develop a group of companies which, at its peak, had mining operations on four continents. That legacy lives on, not just in the employment generated at these mines, but in the hundreds of Irish geologists working at home and overseas.

It started from small beginnings. While working in Uranium City, they spent much of their free time prospecting the area, staking claims and then selling them on.

Returning to Ireland on vacation in 1955 they looked at the country with new eyes, not believing the then dogma that Ireland had no natural resources. During intermittent visits over the course of the next few years, they examined old mining properties and areas of general exploration interest and began to apply the exploration methods that they were learning in Canada. In 1959, they established Irish Base Metals Ltd as a subsidiary of their Canadian registered Northgate Exploration Ltd. It applied for exploration licenses over a number of areas, including Tynagh in County Galway. There evidence was found of strongly anomalous zinc and lead values in soil. Drill testing began in November 1961. During the next three years they defined an orebody which they brought into

production in October 1965. This was the first base metal discovery of modern times in Ireland and established the country as a destination for exploration investment.

This investment resulted in other discoveries. They culminated in 1970 with delineation of the Navan orebody, by Tara Exploration, a sister company of Irish Base Metals. Tara had in fact been established by the four of them in 1953, while in a bush camp in the Northwest Territories of Canada. The Navan orebody was brought into production in 1977 and ranks as the largest zinc deposit in Europe.

Mike was intimately involved with all of these discoveries through his directorship of Irish Base Metals, Tara Exploration and Northgate Exploration as well as provider of drilling services through Priority Drilling Ltd

Priority Drilling Ltd (now based in Kilimor, Ballinasloe) and Priority Construction Ltd were set up in Canada in 1956 to carry out construction on mine sites and mineral exploration. Sixty years later, through the boom and busts, good times and bad times, Priority Drilling and Priority Construction are still working. Mike was there for all of these sixty years. He never retired and even when he became ill 5 years ago and could no longer visit the sites or go to Kilimor regularly, he kept his interest alive. Visits from past and present employees and colleagues brightened his days.

However, Mike also had a life outside exploration and mining. He had a passion for horses. He bred, broke and trained his own horses. He was a true “Horse Whisperer”. He could train any horse or

dog. For 30 years he competed in local fairs with his carriages and traps. Each year at the October horse fair he drove the Queen of the Fair in his carriage at the head of the Parade.

There were a number of events which were always on Mike’s calendar. None was more exciting to him than the Ploughing Championships. This allowed him the double indulgence of large machines and horses in one setting.

In 1972, Mike had his first brush with illness when he suffered a heart attack. He slowly recovered and set himself on a new path of health and fitness. Since walking set too slow a pace, he took up running. Over the course of the next 25 years he ran over 20 marathons, finally retiring after the Dublin City Marathon in 2000 which he completed at age 73.

This dedication to fitness served its purpose for another of his annual outings - Croagh Patrick. Mike had a shortcut – Straight Up. A quick Mass and confession at the summit, some banter with a Bishop or Archbishop and then home in time for the football final at 3pm on TV.

Mike is survived by his wife of 55 years, Teresa Hughes – Pat Hughes’ sister, by his 5 children – John, Miriam, Michelle, Michael and Patrice, and 14 grandchildren.

Note: Thanks to the McCarthy Family and to Priority for permission to use information published on the Priority Website.

John W Arthurs ◼

Mike before he immigrated to Canada in 1948

Mike McCarthy pictured lately

Port Albert, Canada 1952 Pat Hughes (Newry)back left. Mike McCarthy (Skibbereen) back 4 from left. Sitting bottom left Joe McParland (Newry), sitting 2nd from left Matt Gibroy (Enniskillen)

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GOLD RUSH TO OMAGHFoyle College students are guests of Galantas Gold CorporationNicole Sloane describes the day

The day had finally come! On the 25th June 2014 Foyle College’s Year 11 geology class travelled to Galantas’ open cast gold mine at Cavanacaw just outside Omagh. We had been building up to this crescendo for so long and the visit did not disappoint! What a way to end the year!! I had organised this fieldtrip to give the students an insight into mining processes.

Gold is such a scarce but valuable commodity used for everything from a means of trading, computers, electronics, jewellery, dentistry, to help remedy medical situations such as Lagophthalmos, glass making, ornamental uses and so much more!

Our day started with a safety talk and a Powerpoint on the geology of the area by Dr Sarah Coulter (Senior Geologist at Galantas). Her excellent presentation informed students of the geological events that led to the injection of gold into the ancient rocks of the area!

Rocks and core samples were laid out for us on the table in the small field canteen. Over 15,000 metres of core have been drilled during the latest exploration phase allowing Sarah and her team to evaluate the extent of the area of rocks that may host gold. Within both the cores and the rock samples we saw evidence of hydrothermal veins that hosted quartz, feldspar and mica (gangue [worthless] minerals), but also galena (lead ore) and pyrite (commonly known as fools gold) which host gold and silver in the form of electrum. 97% of the total revenue from the mine is generated by the gold found, followed by silver then lead.

Galantas

Galantas owns 220 acres of land surrounding the mine and have exploration licences for 767 km2. The operation to date has centred on open cast mining where bedrock is simply scraped out using mechanical diggers and then sent for crushing and processing. It is currently awaiting a licence for underground extraction of the gold. We saw the place where

the ground is to be broken for an adit. Galantas extract roughly 6,500oz of gold per year, which equates to an amazing 232 bags of sugar! Gold, of course, is valuable and even with the price fluctuating daily (It was £773/oz when writing this but £731/oz when going to press) what seems like a relatively small quantity is worth extracting. Although this generates a large amount of revenue the processing mill uses 135 ltrs of diesel per hour when in operation! Power is the greatest cost in the mining operation in Omagh, followed by wages!

When exploring for hydrothermal gold it is unlikely that you will find the gold in a large seam, so geologists look for associated minerals such as galena, pyrite, chalcopyrite and arsenopyrite. When hydrothermal veins with these minerals are found the cores and channel samples are then sent for chemical analysis to determine the quantity and grade of the ore.

Geology of the area

It is likely that gold is found in the Omagh area because it was carried by magma

Rock containing gold, silver and lead

Presentation


derived fluids associated with the Tyrone Igneous Complex (a series of igneous intrusions that are over 470 Million years old). This hydrothermal (hot) fluid has been injected along faults in the surrounding rocks. The rocks that host the veins are Dalradian in age (595Ma) and form an inlier. An inlier is a zone of older rocks that is surrounded by younger rocks. The Cool Fault to the north and the Omagh Thrust (an extension to the Highland Boundary Fault of Scotland) have thrust these older Dalradian rocks to the surface where they are surrounded by much younger Carboniferous rocks (359-299Ma). The Dalradian rocks are metasediments, mainly psammites (metamorphosed sandstone) and pelites (metamorphosed mudstones). To the west and south lies Carboniferous and Devonian sandstones (sedimentary rocks formed in shallow seas), to the east the Tyrone igneous complex from which the hydrothermal veins originated. The Kearney, Joshua and Kerr veins that host the gold are named after local farmers. The faults and consequently the veins trend mainly N-S. The width of the veins are not consistent; they pinch and swell. They can be as wide as 7m but narrow to <30cm at their pinch points. The veins have been traced to a depth of >300m underground. Galantas have no reason to believe that this is the maximum depth of the veins but once they go underground they will be able to be more confident of the extent of the veins.

A short walk from the site office we were on the periphery of the mine itself. What a sight it was! An open hole in the ground with what looked like an aquagreen pool at its base!! To the

west of this ‘pool’ was the working face of rock that had been excavated. The overburden and waste rock had been dumped into rock piles to the other side of the ‘pool’. When the company eventually start to dig the adit for the underground mine they will use the broken rock to backfill the opencast pit. Not before we took a few samples home (we had permission!!). We are ecstatic to have a piece of rock with gold, silver and lead in it; when reserves start to run low the Royal Mint will be looking for the geology class of 2014! The only clue to the presence of metals in the rock is the colour – some had a purple/lead grey hue – this colour signifies the presence of galena.

The gold extraction process:

To extract the gold from this very hard rock it must be crushed first. The workers have nicknamed the machine that feeds the large fragments of rock into the first crusher ‘The Grizzly’. The rocks that pass through the Grizzly are <30cm. The material is then crushed to ~12 mm before entering the ballmill. The ballmill is a cylindrical rotating drum insulated with rubber. Steel balls are placed inside the ballmill and when it rotates they pound the rock and grind it to the desired size (<75 um). The steel balls are around 80mm to start with but as they pound the rocks they become unrecognisable and distorted.

Collecting samples

1 tonne bags

Finding gold

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The crushed material is then sent to the flotation tanks into a mixture of copper sulphate, PAX (chemical that will attract the metals to the air) and MIBC (a fancy chemical detergent that will make froth bubbles). Air is pumped into the flotation tanks and as metallic sulphides are hydrophobic they attach themselves to the air bubbles and rise to the surface. This metal concentrate now contains gold, silver, lead and minor copper. The ‘metallic soup froth’ then collects and slides down a funnel at the side of the flotation tanks where it is then pressed to remove any water. Ideally this mixture would contain less than 10% moisture content. The solid residue is then bagged into tonne bags and 25 tonnes are shipped at a time to GlencoreXstrata in Canada who process the gold from the solid residue generated in Omagh. A one tonne bag would typically contain enough gold for 20 wedding rings!

Waste

During processing of the rock waste is generated. This fine grained waste is known as tailings. Tailings and process water are sent to settlement ponds. Tailings are finer than dust however may still contain gold. Some of this fine

grained sediment is also reprocessed to ensure every last valuable ounce is collected! The water used during the processing stage may have small quantities of the chemicals used during processing but these are allowed to naturally degrade (into harmless substances) before it can be output back into the rivers in the area. Galantas can output their water as they have an excellent water quality record since they remove anything potentially harmful, however around 90% of water is reused in the mill so that the mill operates in almost a closed system.

Underground

When the licence is granted for the underground mine and it is constructed Galantas have to have 2 power sources for the mine to ensure that if one ever fails then the other can still provide clean air and electricity to reach the mine face. They are currently exploring the possibility of using wind turbines along with generators.

Environmental impact

The mine itself is screened off from the road by trees and shrubs, blending in very well with its surroundings. We

actually drove past the entrance at first! Although the land has been stripped and a large hole dug into the ground the pit will eventually be backfilled and the land returned to its original use (farming and forestry) and not long after animals will be back claiming a stake in this new real estate! All companies are required to return the land to its original use after mining on the surface is complete.

Panning

At the end of the day we had an opportunity to experience gold panning. It was certainly a challenge for some of us to keep the finer grained sediment that contained the gold in the pan! A fantastic day was had by all and the upper sixth students who accompanied us told me it had been worth getting out of bed early! I have no doubt in saying that this was one of the highlights of the year for all of the students.

Thanks

We would like to reiterate our very sincere thanks to the Galantas team at Omagh and especially Dr Sarah Coulter. Not least thanks for a scrumptious Subway lunch! ◼

Letter to the EditorReading between the (basalt) columnsDear Editor, A copy of Issue 16 was passed to me a while back and, on scanning through it, Dr Stephen Moreton’s ‘Reading Between The (Basalt) Columns’ article caught my attention, so much so that I felt obliged to write an open letter to your good self as Editor in response. The views expressed in the attached letter are entirely my own as a private individual. As with my previous open letters, I am pleased that Creation Ministries International (CMI) has been kind enough to publish it on their website.

The letter will be published on the CMI website (creation.com) front page on the 23rd November,. Comments can be posted as soon as it is published. The explanatory notes have been provided to assist non-technical readers.

I trust that my letter will stimulate reasoned debate. Angus Kennedy

[The open letter was too long and came too late to repeat in this magazine but as it has been published already I recommend that interested readers should follow the link given to the publishing website. I leave readers to make up their own minds about the views expressed.

I have to comment on just one item, the last paragraph of Angus Kennedy’s open letter. It states that Dr Moreton makes a ‘thinly veiled attack on Christianity’. That is simply untrue. Re-reading Stephen Moreton’s article it will be found that he stated (Issue 15, page 30, paragraph 2) that ‘It should be emphasised that most Christians have no difficulty with either evolution or the age of the earth. This is not about them.’

As editor I do not accept that debating whether the earth is 6,000 years old or 4.5 billion years old is an attack on Christianity. It is simply a debate about the age of the earth. This magazine respects the faiths and rights of all people. Editor] ◼


The Quaternary of South Africa: the role of the Irish diaspora By Jasper Knight Them and us

For many, the long distance between Ireland and South Africa makes the latter an exciting and exotic holiday destination, but for geologists it offers more than just spectacular landscapes. South Africa has a long geological history that spans from the breakup of Pangaea in the Jurassic, to the formation of huge sedimentary basins such as the Karoo in the late Carboniferous, and to the evolution of present patterns of rivers and coasts during the Quaternary. Rock types exposed on the surface range from granites and deep crustal amphibolites, to diamond-holding kimberlites, to extensive areas of metamorphic rocks – forming some of the world’s largest gold and platinum reserves – and thick sedimentary sequences recording global-scale climate fluctuations over millions of years duration. Furthermore, these rocks and the landscapes developed from them have provided the context for hominid evolution over the last 3 million years, the record of which has been preserved within karstic cave systems, and for the development of unique ecosystems. For a geologist or anyone else with an inquiring mind, therefore, there is a wide range of things of interest, in different parts of the country and in mountain, coastal and lowland settings.

The Irish connection

Apart from the ubiquitous Irish bar, there is a close scientific connection between Ireland and South Africa, in the field of geology. Over recent decades, a wave of Irish-trained Quaternary geologists has added to our knowledge of the South African landscape, its processes and landforms. This is a good example of how scientific methods and an interest in landscape geomorphology can cross international boundaries and bring new ideas and new thinking to some old problems. These Irish Quaternary geologists have used their training in glacial and periglacial geomorphology

to look afresh at evidence for cold climate events and processes in South Africa, a region not thought to have been glaciated during the Quaternary, apart from some small cirque glaciers (but even this is disputed).

The personalities

Four key workers are mentioned here, who have not only been concerned with Quaternary geology in South Africa,

but who have also taught generations of South African students. Colin Lewis received his PhD from University College Dublin in 1966. His research focused on the periglacial geomorphology of the Brecon Beacons, mid-Wales, but in the 1970s he also published on periglacial features in southern Ireland. Since the early 1980s Colin has been based at Rhodes University, in Grahamstown, South Africa, where he has been concerned with evidence for Quaternary glaciation in the Eastern Cape mountains, east of Cape Town. Here, Colin has identified former cirque glaciers and end moraines, and a very wide range of contemporary and fossil periglacial phenomena. In the early 1990s, Colin also worked on periglacial slope deposits with two of our other

Key Books

A river meander incised into Jurassic basalt lava flows, around 2400m elevation in the Moloti mountain range of northern Lesotho

Issue 15 17

protagonists, George Dardis and Patricia Hanvey.

George Dardis received his PhD from the-then Ulster Polytechnic, at Jordanstown, in 1982. His research concerned the Quaternary glacial geology of the Cookstown area, County Tyrone. Until 1992 he worked at the University of Transkei, at Umtata, South Africa. During this time, George was concerned with a wide range of geomorphological problems including slope processes and soil erosion, with a particular emphasis on how Quaternary climate changes resulted in changing patterns of slope sedimentation. Addressing these problems, George worked particularly with a fellow Ulster graduate, Patricia Hanvey.

Patricia Hanvey received her PhD in 1988 from the University of Ulster at Jordanstown, where she looked at the glacial geology of Clew Bay and

Donegal Bay, in particular, drumlin sediments. Until 1991, Pat worked at the University of the Witwatersrand in Johannesburg, South Africa. Here, her research was mainly concerned

with periglacial and slope processes, especially their sedimentology and climatic interpretation. During this time, she continued working with George on the sedimentology of Irish drumlins.

The fourth researcher discussed here is Jasper Knight, who received his PhD from the University of Ulster at Coleraine in 1997 and who, like George and Pat, was supervised by Marshall McCabe. Jasper’s research focused on the glacial geology of Counties Tyrone and Fermanagh. He also worked on drumlin sedimentology in western Ireland, convening the VII International Drumlin Symposium in Westport, in 2010. Since 2011 Jasper has worked at the University of the Witwatersrand in Johannesburg, South Africa, and been concerned with the geomorphology of mountains, rivers and coasts. He has also, like Pat, worked on glacial and periglacial evidence in the Drakensberg mountain range in central South Africa.

The legacy, the future

The Irish landscape is a great training ground for field skills in Quaternary geology, which can be applied to landscapes worldwide that have been affected by Quaternary cold climates. The key workers described here are but some of the Irish geological diaspora that have brought their expertise and enthusiasm to bear on geological problems far from home. We need to continue training the geologists of the future, in the superb field sites of Ireland, so that they can in turn continue the legacy of these and other workers at home and abroad. ◼

View looking south from Table Mountain, overlooking Cape Town

Working on a geomagnetic survey in the Vredefort meteorite impact crater

Bedrock control on the Sabie River, near Kruger National Park


GRANITE & GLACIATION IN SOUTH CONNEMARAJonathan Wilkins takes a personal look – after spending too much time in a laboratory analysing rocks for other people.

Introduction

The landscape of South Connemara is not as well-known as it might be, but closer examination shows some interesting features relating to both very ancient and much more modern geological interludes. For granite to be visible at the surface, some rather radical erosion has to take place because the magma from which it crystallises must freeze at a depth of between 3 and 10 km. This problem and that of how the space for the body of the intrusion was created has driven geological research for many years.

This article is about the present disposition of the Galway Granite (see map), which is one of the largest granite batholiths of the North-west European continental crust, stretching from the outskirts of Galway City (GC) to the vicinity of Slyne Head (SH). An isolated pluton at Omey (O) is also part of the batholith, although slightly older. The age of the intrusion is around 400 million years, so it relates to the Acadian period when the great Caledonian mountain-building episode was on the wane and the deeply-buried crust was melting in response to de-pressurisation. Granite magmas collected in the area between major faults which continued to move for a long time as the continents of Laurentia and Avalonia ground past each other. Exposures of the contacts between the metamorphic country rock (striped

ornament) and the granite plutons are rare, and difficult to reach, except at Roundstone (R) on the seaward slope of Errisbeg, where the contrast between the dark, metamorphic rock at higher elevation and the pale granite is so great that it can be seen very clearly from a considerable distance. Beaches around Slyne Head are worth visiting (especially on a rainy day) for their beautiful, green-coloured outcrops and pebbles of metamorphosed basaltic intrusions showing an original igneous layering of white plagioclase feldspar crystals.

Granite outcrops

Examination of the granite outcrops across the area today show clearly that a number of quite distinct pulses of magma coalesced at depth to form the

batholith. Crystallisation of the granite at a depth of 10km or more beneath the surface was not the end of the matter, because the low density of the solid rock caused it to continue to rise, lifting the local crust with it, or moving along steep faults around the margin. This process resulted in its breaking to the surface before the deposition of the Carboniferous Limestone across the district, but its ascent and erosion have continued subsequently, assisted by tropical weathering conditions during the Tertiary period and the continuing movement of the boundary faults during the opening of the North Atlantic Ocean from about 60 million years ago. Major faults also cross the granite batholith (see map) along which thrusting and vertical movements have allowed the elevation of a deeper part of the batholith so that it sits next to the roof zone. Thus, the Main Granite Suite (+ ornament) which lies between the Shannawona Fault (SF) and the Barna Fault (BF) has ascended by 3.5 km relative to the enveloping Errisbeg Townland Granite (-) outcropping across most of the area described here. This elevation can be detected by detailed analysis of rare amphibole crystals which are the only mafic minerals to be found in the granite apart from biotite. Of great interest is the recently-mapped thrust fault zone (not shown) running through the Furnace district which demonstrates a westerly movement of around 1.7km laterally within the Errisbeg Townland Granite. Within the Magma Mixing Zone (MMZ, dotted ornament) it has been demonstrated that some production of magma was more mafic than the granitic majority, and a zone of magma-mingling has been demonstrated in the centre of the Main Granite. The batholith is therefore far from homogeneous and a particular feature of the local geology

Sketch map of the geology

Maumturk Mts viewed across the great bog occupying eroded granite to west of Maam Cross

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is the continued ascent and erosion of the granite; the legacy of the last glacial maximum demonstrates how rapid and effective that process can be.

Influence of glaciation

During the Last Glacial Maximum ice covered Ireland completely, although the limit of the ice sheet was not far off the midland west coast. Ice up to 600m thick buried the mountains of Connemara and ice streams clawed at the land surface, loosening material and carrying it away westwards. The great weight of ice pushed down the continental crust by around 160m, but the great difference in elevation was countered by the lowering of sea level by a similar amount as the water was frozen and piled onto the land. Although granite is quite a hard rock, it can be eroded quite quickly because it is cut by systematic joints which relate to tensions in the crust at the time of crystallisation. Large blocks can be split from outcrops and carried away, becoming more or less rounded as they are dragged along by the flowing ice, rasping at the surface in turn and

leaving long scratches across flat rock surfaces as they go. The Galway Granite is intruded into deformed, high-grade metamorphic rocks which resist the forces of erosion much better, so the granite outcrop is much lower than the famous Twelve Pins and Maumturk Mountains, often completely flat and barely above sea level.

Eventually, the climate improved, and by 26,000 years ago the ice had become stagnant and melted at low altitude, dumping the load of material that was in transit across the landscape. Melting of those ice sheets released water back into the oceans, which rose world-wide as a result, but the land also bounced back as the weight of ice was reduced. A ding-dong battle continues to this day as the crust settles to a comfortable level, quite apart from a world-wide rise resulting from climate change and the melting of modern ice-caps. Because the ice-load was not evenly distributed, some areas have rebounded further than others. In western Britain the coast is rising faster than the sea, and

spectacular raised beaches can be seen in the Hebrides and on the Galloway and Antrim coasts. In my observations of the South Connemara coast I fell into the trap of assuming initially that the pattern across Ireland was similar!

What you see in the field

But that’s enough theory. What do we see in the field and of the Errisbeg Townland Granite in particular? Fresh granite can be seen in many working or disused quarries in the district and it is widely used as a walling stone in grandiose, modern enclosures. It is predominantly pink in colour due to the abundance of potassium feldspar, which is notably porphyritic with phenocrysts reaching 25-30mm in length. Grey quartz and whitish plagioclase make the remainder of this pretty rock. Notable is a tendency to greenish alteration of the plagioclase, but this is not universal and some parts show a greasy white instead. The two colours are often very closely associated. Mafic minerals are not very abundant. At outcrop the surface is profoundly bleached by long exposure to

Glaciated, erratic strewn granite pavement of Gorumna Island,; Leitir Moir in distance

Fossil tree-stump buried in peat for 5.000 years is eroded by the sea at Rosmuc

Ice transported granite blocks on lower slope of An Gort Mor

Sample of Errisbeg Granite pluton showing greenish feldspar alteration; large pink phenocryst is 30mm long


acidic water from overlying peat. Most locations show a pervasive jointing in a NNE-SSW direction, and this echoes the disposition of the Shannawona Fault. To the west of that fault the Errisbeg Townland Granite forms almost the entire coastal outcrop until Roundstone is reached.

To the north lie the mountains, comprising tough metamorphic rocks which stand high like an amphitheatre, reaching 600 or 700m, while much of the granite is underwater and reaches a mere 350m in the only sizeable hill, Cnoc Mordáin. The other peaks are Cashel Hill, An Gort Mór and Camus Hill ranging from 310m to less than 100m. On a fine day the southerly view from any of them is without parallel - a patchwork of islands that stretch as far as you can see comfortably, only one of them with hills of any height, Leitir Móir at just over 100m. The long, complex peninsula of Rosmuc is very nearly an island but has a central, rocky ridge preventing the sea from closing around it. The rest is a wide expanse of shallow water which surges to and fro with the tide through narrow passages and wide expanses of seaweed-encrusted boulders. Much of the land is less than 30m above sea level and almost all of it less than 60m. Large areas are scraped bare and the thin peaty soil supports only furze and heather, while erratic boulders abandoned by the ice sheet litter the landscape, ranging in size from useful stones for building walls to behemoths the size of a bus. Inland, the bowl of the amphitheatre is occupied by a vast blanket bog with myriad lochs in the hollows - and this is where the confusion starts. Spring tides creep almost imperceptibly into the bog many kilometres from the ‘sea’, and the presence or absence of the ubiquitous Bladder Wrack seaweed is the only indication of salt or fresh water. Some larger lochs have busy, tidal rapids through the narrows beneath bridges which carry the R340 and minor coastal roads. Many islands of this curious archipelago are linked by causeways initiated in the late 19th century to relieve the desperate poverty of the people. Another takes traffic to Máinis near Carna, and that was where I realised that something strange was happening. Close to the laboratory of NUI Galway’s Ryan Institute the tide was flooding sinuous channels in a peat bog, not a saltmarsh as I had first supposed, and peat bogs don’t accumulate in salt water.

Peat and sea level changes

The history of peat is about as different as you could imagine from that of granite and it originates through the preservation of organic material, mostly moss, which accumulates under waterlogged, anoxic conditions. The bogs of Ireland are not all of the same age, but few are anything like as old as the final melting of the ice sheet which covered this area around 22,000 years ago. Dating by carbon isotopes gives the peat an age of around 5,000 years and it is believed that much of it formed as a consequence of early farmers cutting down the forests which had clothed and dried the land. Sheep are also implicated in maintaining the status quo! In my travels around the coast of Rosmuc I found two localities with vigorous erosion by wave action and a similar stratigraphy. Granite outcrop is overlain by a thin layer of stony till, comprising crushed and weathered granite, above which there are numerous tree stumps with radiating root plates, apparently in their life position. These stumps are then buried beneath a variable thickness of peat, up to 2m in one locality. Whether the trunks were cut or had rotted away before burial is unknown. The level of the stumps is below the highest tide level, and it has to be assumed that they didn’t grow with their roots in the sea. So here is very powerful evidence that sea level, to my surprise, is rising in this area, and demonstrably over quite a short time scale. Changes in the disposition of the shoreline can be very complex and difficult to unravel where there is sediment redistribution in the form of shingle bars and sand dunes

which comprise re-mobilised glacial sediments, but here there are virtually none. There is just peat and granite bedrock or boulders, and once the peat is suspended in the seawater it floats away and is completely lost.

The sea level rise is well known, it turns out, and is the consequence of much thicker ice in the northern part of the country causing a stronger isostatic rebound. The crust beneath southern Ireland is being levered downwards by this movement, so Belfast, Dublin and Donegal are going up and the southern counties including Galway are going down. As the sea is also rising slowly world-wide due to warming, the picture is less simple than it is drawn here, but it is certain that the sea has encroached considerably onto the land around Galway Bay since the ice melted, and the more recent effect is demonstrated very clearly in these key localities. Erratic boulders are everywhere on the South Connemara shore, but I had not expected that they were mostly surrounded by a blanket bog until it was claimed by the sea, and that the strange, watery landscape is indeed being shaped by a slow drowning.

Acknowledgements

I have drawn on the work of Bernard Leake, Martin Feely, Marshall McCabe, Richard Carter, Sadhbh Baxter and their co-workers and I thank them for their assistance where appropriate. The sketch map is based upon published work by Baxter, Leake and the Geological Survey of Ireland. Photographs are all by the author helped by the spaniels. ◼

Glacially smoothed granite outcrop by Turlough Quay looking towards Croc Mordain

Issue 15 21

McKinstry’s Dictum: Geological Maps in Mineral ExplorationBy John ArthursAs a passionate advocate for the application of science in mineral exploration, Roy Woodall tells the story behind one of the world’s great gold discoveries: “When the famous American geologist, Dr Hugh McKinstry, came to Australia in 1933 ... what did he and his geologists “see” at the abandoned gold mining centre at Norseman in Western Australia? Not a mined out quartz vein which had

bottomed because of the vagaries of a mysterious hydrothermal system, but a link structure in a major reverse fault system, and therefore the possibility of other gold-bearing reefs at depth. This simple improvement in “vision” made possible by science produced three million ounces of gold worth over $1.5 billion” (Woodall, 1983).

We know what must have led McKinstry to “see” because his classic1948 textbook on mining geology begins, “A map is a record of geological facts in their correct space relations – facts, be it noted, not theories. There must always be a sharp distinction between observation and inference.”. McKinstry’s “vision” at Norseman surely began with geological maps and sections. He must have filled in the blank space beneath the existing mine openings and drill holes with his own theory about where undiscovered gold-bearing veins might be found.

The “geological facts” which McKinstry emphasises had, and still have, their source in the traditional geological field skills of hand specimen identification, mapping, core logging and sampling. With the powerful and increasingly sophisticated addition of geophysics and geochemistry, the essential skill of a latter-day exploration geologist still is the ability to see the connections between the facts and to create the vision of where a new discovery could be found.

If the language of engineering is design then perhaps the language of mineral exploration is geological mapping. Mineral exploration is a spatial science. The fundamental questions it addresses are where is the mineral deposit located in space and what shape and size does it have? Our understanding of the geology of a mining district or mineral property is expressed in geological maps and drill sections. They are the text in which the prospector develops and communicates the geological model to other geologists, as well as to directors and investors.

Subtle changes in nuances and tone in any language alter how the message is perceived. In the same way, geological maps and sections can be presented without us being fully aware of hidden inconsistencies and biases. Even though McKinstry wrote his textbook more than 65 years ago, it is still regrettably common to see maps and sections shown which blur the distinction between facts and

theory. Interpretative geological maps and sections, the ones we normally see in presentations to investors, represent current theories. The dependant assumptions may remain unspoken, even unrecognised. By closely examining a geological map and recognising gaps and hidden assumptions we can revise our understanding of the geology of the mineral property and create investment success. Note that, in this sense, “success” can be either the rationale for continued exploration investment or else early withdrawal, thus saving cash for another opportunity. Whichever it is, McKinstry’s Dictum is at the heart of any successful exploration programme.

What are the Essential Features of a Geological Map?

McKinstry insists on making a clear distinction between observation and inference because mineral exploration necessarily involves inductive reasoning. Unlike deductive reasoning, which guarantees proof on the basis of the premises supplied, observational science can only produce a probable conclusion. Even with good evidence, our interpretation of the geological situation can still be wrong. The best we can do is to carry out investigations which test the current interpretation for falsity. McKinstry, in drilling below the worked-out mine at Norseman, could only look for evidence to disprove his predecessors’ conclusion that the vein was exhausted. The first successful drill intersection did not, by itself, necessarily prove that a new deposit could be found and mined, only that the interpretation current at that time was wrong. The only proof that McKinstry’s inferences were

Hugh E. McKinstry, Professor of Economic Geology, at his desk at Harvard, circa 1959. (Courtesy of the Society of Economic Geologists, Inc.)

The Norseman gold mines in the late 19th Century. (With thanks to Moya Sharp, www.outbackfamilyhistory.com.au)


correct was when renewed mining finally exposed the ore.

In looking at historical exploration maps and sections, we need to bear in mind the rational purpose and process of exploration and use that to guide us in assessing the quality of the data before us. This, in turn, allows us to evaluate the geological model on which the exploration is based and identify where there might be gaps and flaws in the chain of evidence. Following McKinstry’s Dictum, we suggest that there are five essential and interrelated features of an effective geological map:

1. Not One, but Two (or More) Maps McKinstry’s Dictum calls for “…

geological facts …”. The practical result is what we would call an outcrop map or a fact map. Clearly, that is insufficient by itself. The field geologist is closest to the data and should have the responsibility to draw conclusions from the evidence he/she has collected. So there also must be an interpretative map. In large data sets, a GIS platform is required to produce a set of several maps of the same area, not just one or two, with an interpretive map as the link between them all.

2. A Four-Dimensional Geological Model The phrase “… facts in their correct

space relations” implies that a two-

dimensional surface map should be drawn with structural data to enable cross-sections to be constructed to show the third dimension in a cross-section. The task is eased nowadays with mining software which draws 3D images of ore deposits. Note that the “when” in geological systems usually also conditions the “where”. Following the laws of superposition and cross-cutting structures, the spatial context often implies the temporal sequence. Maps and sections should therefore be presented which enable us to infer the sequence of geological events. In effect, a geological “map” is the expression of a total 4D geological model.

3. Logical consistency The geological map (or set of maps

and sections) should be drawn to allow readers to follow the chain of evidence from factual observations, such as outcrops, minor structures, drill holes, geophysics, geochemistry, etc., to the geological model or theory upon which they depend. The reliability of the inference should be apparent from the density and type of observations shown. Reliability can be made clear by symbology (e.g.: varying styles of solid and dashed lines to indicate the degree of uncertainty about the location of a geological boundary).

4. Drawing Consistency Without consistency and of map

elements the map will necessarily be inaccurate and misleading. Consistency in the location reference system, topographic features, nomenclature, symbol systems, surface projection of 3D bodies, and interpretive principles is essential. As a corollary, the legend, or key, is an essential part of the map.

5. Fit for Purpose and Truthful The geological map needs to include

all the data necessary and sufficient to express the model which drives an exploration programme. With a lack of focus on possible geological models, it is easy to miss significant evidence which should have been collected. Alternatively, out of fear of missing something important, it is common practice to collect a huge range of very detailed geological data from all available sources. Not only does this waste time and money, it is potentially overwhelming and misleading. The map-maker needs to steer a course between showing too much irrelevant data, providing only evidence to corroborate his/her preferred geological model and showing data which supports alternative explanations.

I would like to add that the geological map should be aesthetically satisfying, although, in practice that is not a logical necessity. However, a pleasing colour scheme, a clear layout and an elegant interpretation do go a long way towards making the geological model more acceptable and persuasive.

References:

Woodall, R. 1983. Success in mineral exploration: confidence in science and ore deposit models. Geoscience Canada, v11.No3. pp127-132

McKinstry, H.E. 1948. Mining Geology. Prentice-Hall Inc. New Jersey.

Since 2009 John has combined training, executive coaching and mentoring with his established geological consultancy practice to help international mining and exploration companies with issues in professional staff development. E-mail: [email protected] ◼

An example of a gold discovery made by drilling after solving a fault problem at Eureka, Nevada. Colours added: yellow = gold ore, red = discovery drill holes. (From McKinstry, 1948, Fig.110, Prentice-Hall Inc., with acknowledgements to William Sharp)

Issue 15 23

Julius Hanna, mineral collector - A little more is knownPatrick Roycroft writes:Preface: In a previous issue (14, p 4-5) of Earth Science Ireland, Kenneth James of the Ulster Museum wrote about the mineral collection of Belfast industrialist Julius Hanna but could give only minimal details about Hanna himself: seemingly, nobody has written about him. At the end of the article, ESI’s Editor, Tony Bazley, asked if any readers/genealogists could find any additional information on Hanna. By coincidence, I had recently given an Irish Geological Association workshop on how amateurs could do their own research; this included a section on how geologists could use genealogical techniques to solve just such a problem [Next issue will have more]. I offer the following short chronology of Julius Hanna to answer Tony’s plea. But I want to emphasise that all the information below came only from following the basic advice given in the IGA workshop, and it could have been done by anybody. In the process, I also found out about Julius’s parents (John Alexander Hanna and Julia Spackman), his two grandfathers (James Hanna and William Spackman), several great aunts and uncles (one great aunt, very unusually, married an Italian man in Shankill, Belfast, in 1853!), and a first cousin who also became a prominent Belfast businessman. But their stories can wait for another day.

Julius Hanna was born Julius Alfred William Henry Spackman Hanna on 27 November, 1866, in Holywood, Co. Down, some 6 km NE of Belfast (Antrim). His parents were John Alexander Hanna (1835 - 1913; managing director at Musgrave and Co. Ltd. and an inventor with three patents to his name) and Julia Spackman (b.1845 - d.1866), and they were married 17 March, 1866, in Belfast. So, either Julius’s parents married when Julia was about one month pregnant with Julius and she gave birth after 9 months, or she became pregnant around the time of the marriage but gave birth after only 8 months. Tragically, Julia died giving birth to Julius, or very soon thereafter, possibly the result of early labour and complications. She died aged only 21.

On 2 September 1882, when Julius would be about 16, there was a large bazaar held at Knock, where the family was living and close to where Julius had been born, by the young people of the congregation of Dundela Presbyterian Church. The bazaar was held in the then-new Sabbath-school building that is attached to the church. The proceeds were to go towards paying off a remaining £200 debt for the cost of the new building. John Alexander Hanna (Julius’s father) contributed to the bazaar by donating various plants (e.g., tree ferns, plants in pots, hand bouquets, or single roses). Julius Hanna ran the post office stall for the day.

Some three years later, on 19 October 1885, there was the annual entertainment evening held at the Presbyterian Dundela Sabbath School, Knock. This was of the educational entertainment type and was given to the young scholars in the schoolroom itself. Fruit was given out to the children, various Reverends said their pieces, and a choir sang “Jessica’s First Prayer”. Julius Hanna (aged 19) then read the story behind this song, and it was noted that he read it in such a way as it showed how carefully he had grasped the pathos of the tale.

In his early 20s, Julius attended a

number of a banquets and receptions. Around 20 September 1889, there was a banquet held in the Ulster Hall in honour of a visit from the recently titled Marquis of Dufferin and Ava - aka, the triple-barrelled Frederick Hamilton-Temple-Blackwood. Many attended, and among those honouring the new Marquis was Julius Hanna (age 23), stated as still living at Knock. And around 3 April 1891, there was a visit to Antrim by Sir Henry James, for whom there was a large reception at the Ulster Reform Club and at which important deputations were delivered by representatives of the local community. This was a far more serious anti-Home Rule gathering, and Sir James was there primarily to reinforce Protestant interests and business in Ulster and to reinforce the unity of Protestants in Ulster. Many hundreds attended this enormous “business lunch”: the stated theme was Ulster loyalty, Ulster industry, and no toleration for Home Rule. Several members of the Hanna clan were present, including Julius (aged 24).

In the 1891 census, taken on April 5th, we get a curious titbit. Julius Hanna (aged 24) was with an Ethel Hanna (aged 14, no indication of her relation to Julius though he must be looking after her), both from Ireland, and they were staying in England as ‘visitors’ at the Prince of Wales Hotel in West Park St., Harrogate, in Yorkshire. This does look

Rubellite crystals


like our Julius [name, age and birthplace are correct] and his profession is stated as ‘Iron Founder’. If this is our man, he might have been doing some training ‘abroad’ for his career at Musgraves and Co., where his father was a managing director. The year 1891 was also an especially important one for Julius. Sometime in the April-June quarter of 1891, Julius married Isa Calder in Belfast. They never had any children. Thus, Julius was an only child and he himself died childless: so there are no direct descendants of Julius Hanna.

Around 17 September 1896. Julius Hanna (aged 30; described now as an ‘esquire’) was noted to be on board the Royal Mail route ship from Larne to Stranraer as a saloon passenger; he may have been travelling regularly to and from Scotland.

The following year, on 24 April 1897, Julius (aged 31) attended a meeting at his old school of Dundela for the purpose of forming a local lacrosse club. The idea was passed and Julius, who was presiding over the meeting, was then elected the club’s first Captain.

Some insight into the domestic life of the married Julius can be gleaned from an advertisment that appeared in the Belfast Newsletter of Friday 27 May, 1898, from Mrs Julius Hanna (i.e., Isa), for the sale of some newly hatched pure-bred Indian game chickens. The price was nine for 15s or, with hen, 17s 6d. The reply address was given as Ruedesheim, Knock, Belfast. The Hanna’s would appear to be at least partly self-sufficient.

The 1901 census, taken on 31 March, records Julius Hanna (34) as head of the household, Presbyterian, born in Down, and with the profession of a heating and ventilation engineer. Isa (34) is his wife, Presbyterian, and born in Antrim - in fact, she was born in 1867 in Belfast. They have a female servant in Catherine McKenna (Catholic, 25, from Monaghan), and they were all living at 176 Albertbridge Road, Pottinger, Co. Down - on the same road as Musgraves. However, later in 1901 Julius, described as an engineer, moves the family to Paulett Avenue, which is a small street just off Albertbridge Road.

And in 1902, Julius and Isa move again, this time to Brandon Tower, off (11) Sydenham Park. He is now described as a manager at Musgrave Ltd. He is evidently following closely in the footsteps of his father. Musgraves had been originally founded in 1843/44 by several Musgrave brothers (and their uncle) and initially specialised in ironwork (in 1890, for example, they supplied the ironwork for the bandstand in Dublin’s Phoenix Park), but diversified into manufacturing ventilation equipment, stoves and other kinds of machinery. The company was central to the careers of both Julius Hanna and his father, John Alexander Hanna. Julius remained at Brandon Tower until 1910, when he moved again, this time to Park Avenue, with Julius still described as a manager at Musgraves.

I couldn’t find Julius on the 1911 census, taken 2 April; at the very least, he is not at home with Isa. However, Isa Hanna is recorded as 44 years old, married for 19 years and with no children; also in the house was an Ethel Thomas (34, from Belfast, visitor) and a female servant (Emma Hutton, 27, from Down). In 1911, they were living at 11 Park Avenue, Victoria, Co. Down.

Moving house seems to have been quite a thing with Julius, for in 1918, while still being a manager at Musgrave & Co. Ltd., he and Isa move yet again, this time to The Den, Station Road. But the reader should be aware that, despite all the different addresses (and remembering where the border lies between Down and Antrim), in effect, Julius was born, bred and worked in what is effectively East Belfast.

Julius died 17 August 1925, aged 59. His last address was at Lismoyne in Dunmurry village, some 7 km SW of Belfast. He had an earth burial on 19 August 1925 in Belfast City Cemetery. His wife, Isa, considerably outlived him, passing away, it says on the gravestone, aged 75 on 01 July 1944. Oddly, her age here conflicts with her census and birth record ages, which would actually make her 77 upon death. If you want to pay your respects, they are both buried in grave J 428 in Belfast City Cemetery.

[Editor - Can anyone find a photograph of Julius Hanna or some Musgrave records to add to this?] ◼

Rubellite crystalsWater-melon tourmaline crystal

Congratulations to Students and TeachersThese were the best in Northern Ireland in this year’s Geology A level exams. Note the great success on a UK level:

AS

1st - Jamie Walsh - Methodist College (Ranked 11th in UK) 2nd - Andrew Dickson - Foyle College 3rd - Ethan Lapsley - Foyle College

A2

1st - Bethan Heath - Foyle College (Ranked 4th in UK) – Bethan is now studying geology at St Andrews University. 2nd= - Conor Boland - Methodist College 2nd= - Connor Mckee - Methodist College 2nd= - Conor Forbes - Methodist College

Issue 15 25

Finding ‘proper’ Earth Science data in the maze that is the InternetGearóid Ó Riain points the wayMuch progress has been made over the past decade or more in the creation of digital datasets; datasets often created under programmes of work that have been required by EU Directives alongside national and local initiatives. However how do we find such datasets when these data can also be lost in the digital equivalent of filing cabinets?

In response to this data discovery challenge, the concept of metadata catalogues have grown steadily, with associated standards. These catalogues provide ‘data about data’ – descriptions of datasets so that the potential user can assess if the data is fit for the purpose planned, and can understand the conditions around use of that dataset, such as licensing. This metadata is set out in a standardised structure and is also served out live from the catalogues so that the metadata can be read and shared by users and machines in a consistent way.

What about the data itself? It is work in progress but gradually datasets are being improved and are being made available as ‘live’ web services where you never need to download the data but rather link live to it within your software – such as GIS. A range of ISO standards have been developed so that computers and software know what to expect and how to handle these data web services.

Initiatives are also on-going to save data from loss – these are often datasets

which might have been generated through local projects and are stored on local drives or datastores. It is this type of data where the Heritage Council’s National Biodiversity Data Centre and also its Heritage Viewer, just as two examples, play a valuable role – finding, saving, improving and publishing data – with metadata catalogues, data web services, and also data visualisation through maps, graphs, and tables.

So what about earth science data? Where do I go to find it?

The Irish Spatial Data Exchange (isde.ie) is a metadata catalogue that focusses on data from the Geological Survey of Ireland, the EPA, the Department of Environment, Community and Local Government, the Marine Institute, and

the Coastal and Marine Research Centre (UCC), along with seven other agencies and also local authorities. The user can search the catalogue by keyword, topic, date range or by map with the dataset description being returned, including links to data web services or data downloads or viewers where available.

A related earth science resource is the Marine Data Online system (http://data.marine.ie) from the Marine Institute that provides another route into the ISDE metadata catalogue and additional data search and download features. The Marine Institute’s new integrated Digital Ocean initiative (www.digitalocean.ie) is also worthy of mention as it is looking to apply new technologies, including Microsoft Research’s FetchClimate application, to provide an integrated digital view of Ireland’s marine territory. Initially this is to support the research community but it will also be used for public services as it matures over time.

Another more recent and broader catalogue is the pilot national Open Data Portal (data.gov.ie) currently containing over four hundred datasets from 45 public bodies. The portal is operated by the Department of Public Expenditure Reform and developed by the Insight Centre for Data Analytics, NUI Galway. This service, like similar data.gov.uk and data.gov sites in the UK and US, using the same base software, focusses on a whole range of datasets across organisations and across data types.

Data download and visualisation sites of particular note regarding earth science


include the Geological Survey data downloads site (gsi.ie/Mapping.htm) and the EPA’s geoportal (gis.epa.ie), while services such as the OSi’s geoportal.ie, and the All-Ireland Research Observatory site (airo.ie), among others, provide broader coverage.

The author’s colleagues have had the privilege of supporting the ISDE, Marine Data Online, EPA and other portals, including – to mention again - the Heritage Maps initiative (http://www.heritagecouncil.ie/maps/welcome-to-

heritage-maps/). Heritage Maps allows you to look at a wide range of built and natural heritage data sets in map form, much of which have never been accessible to the public before, and also provides metadata on these. It also combines biodiversity data from the National Biodiversity Data Centre systems (biodiversityireland.ie).

The above note is a short summary and introduction to the discovery of earth science data and access to that data. It is not by any means exhaustive. Importantly

the same cataloguing and web services approaches can be used internally within organisations to facilitate the saving and sharing of data, allowing organisations to efficiently combine internal datasets with external local, national, and international datasets.

Technical note: The ISDE on-line system uses open source GeoNetwork catalog software ‘under the hood’ with .Net coding of the website and an open source Open Layers map viewer. The Marine Data Online uses similar technology with a screen design that responds well to different screen sizes. The data.gov.ie service uses the very useful CKAN software which is similar to GeoNetwork but seeks to support the storage and sharing of data in many different formats and is well suited to broad open data initiatives and also for multi format intranet catalogues.

Gearóid Ó Riain is founder and managing director of Compass Informatics, an information and location technologies company. ◼

Belfast Geologists’ Society David Kirk reportsMixed weather had its effect on the Belfast Geologists’ Society summer programme of field trips but, nothing if not intrepid, the members did not allow it to put them off.

The season began in April with an evening excursion to the north Down coast with Bernard Anderson leading a walk through the best, and classic, exposures of the Ordivician-Silurian Moffat shales around Donaghadee.

In May Mark Cooper and Gareth Barker

led an outing again to the Ordivician-Silurian shale structure, but this time to the Down-Armagh border to reveal the graptolite localities which have been discovered using Tellus Electromagnetics - along with some good old-fashioned fieldwork.

June saw two trips – one in the evening of 18th to examine the building stones of Queen’s University led by Ian Forsythe and three days later Robert Raine demonstrated the importance of the Triassic sandstones under Scrabo Hill as a valuable water source.

August 2nd was one of the wettest days of the year and also the date of Ian Meighan’s Presidential excursion to study the Palaeogene plutonic and volcanic rocks of Slieve Gullion and Carlingford. To add insult, when the members arrived to start the drive round Gullion they found the road blocked by a fallen tree! Undaunted they drove to the extensive rock exposures revealed by the cutting of the new motorway where Ian ably demonstrated the sequence of events that created this dramatic scenery.

Final event of the season was in October when John Walsh of University College Dublin led members in an examination of the structure of the rocks in the Carboniferous Dublin Basin around Loughshinny.

Now, the indoor winter lecture season is well underway. So far we have heard a fascinating description of the rocks of the Cape Verde Islands by Jim Floyd, of the British Geological Survey and Dave Chew of Trinity College Dublin has explained the tectonic evolution of the Laurentian margin in NW Ireland and Scotland. Rob Raine then asked ‘What lies beneath’ and peered into our own basalt lava covered region of NE Ireland and that of India.

Still to come on 19th January is Adrian Finch from the University of St Andrews with an enthralling title of ‘Smart phones, i-Pads, laptops…igneus geology and exploration for critical metals in Greenland’. This is followed on 16th February by Sam Robertson of the GSNI with something appropriate for the month, ‘Periglacial Ireland: looking for frozen ground’. Maybe just step onto the grass of the Botanic Gardens?

Finally, the Harold Wilson Memorial Lecture will bring back Donny Hutton of Bristol University to give an overview of the Donegal granites, a topic that blends spectacular scenery with international quality science. This talk will be given on 16th March with the Annual General Meeting on 20th April.

Further information about events and how to join the society can be found at www.belfastgeologists.org.uk. We are always happy to see new faces. ◼

Carlingford August - President Meighan explans!

Issue 15 27

NEW GROUP HITS GROUND RUNNINGGeological Society of London – Northern Ireland Regional Group

Mike Young may have retired as Director of the Geological Survey of Northern Ireland but he remains very much on the Irish Scene. He holds the prestigious position of a GSL Council member and so is able to actively promote Northern Ireland. As part of that responsibility he has put right what has been a glaring omission in the GSL – the fact there was no Northern Ireland Regional Group. He held exploratory discussions earlier in the year, a useful niche was identified and the Northern Ireland Regional Group was formed.

The Fellowship of The Geological Society in Northern Ireland is broadly distributed across the mining industry, engineering consultancies, the universities and the Geological Survey. The objectives of the group are to foster the aims of the Society and to provide professional support and networking opportunities for Fellows, through meetings, field excursions and participation in activities to promote the earth sciences.

Its meetings are open to all. Although the Group is focused on Northern Ireland it warmly welcomes participation from Fellows anywhere in Ireland and members of other earth science societies, which the Group hopes both to complement and support.

The Group contributes to the Learned

Societies and Professional Bodies Forum, which provides advice on scientific issues to the All Party Assembly Group on Science and Technology.

For the record:

Chair, Mike Young, GSNI, Secretary, Thomas Cash, RPS [email protected] Treasurer, Sarah Coulter, Galantas Committee Members, Mark Kelly, MK Environmental ; Paul McErlean, White Young Green

So far the group has visited the Cavanacaw gold mine and Curraghinalt gold project, County Tyrone, been present with a stand at the annual ‘Science and Stormont’ seminar and exhibition, Parliament Buildings, Belfast, and held its own reception and Inaugural Lecture. The latter, on Monday 27th October, took the topic ‘Geology and the low-carbon economy’ and was delivered by Professor Paul Younger of Glasgow University. It was attended by around 150 people.

For future events, there is a joint GSNI and ICE excursion next May, check the GSL web site or email Thomas Cash, [email protected]

Editor ◼

We take off our hats to:Professor Charles Hepworth Holland of Trinity College Dublin has just published a paper entitled “Biostratigraphy of British Silurian nautiloid cephalopods” in the Bollettino della Societa Paleontologica Italiana 53(1) 2014, pp 19-26.

Ireland’s most distinguished geologist, Professor Holland was a founding member of the Ludlow Research Group that has been so influential in Lower Palaeozoic research. He will be used to plaudits but there are not many who continue to carry out top level research into their tenth decade.


A TALE OF TWO MAGMASFiona C. Meade & Valentin R. Troll, Uppsala University, SwedenA new scientific paper, recently published in the prestigious journal Nature Communications, uses detailed chemical analyses of rocks from the Carlingford Igneous Centre, a large, extinct volcano in northeast Co. Louth to investigate a 160-year-old geological conundrum. The article offers a new perspective on how some of the most explosive volcanic eruptions seen on Earth might come about.

The British and Irish Palaeogene Igneous Province (BPIP) formed 60 million years ago, when America and Europe were slowly breaking apart and the North Atlantic Ocean was only beginning to open. This process was exacerbated by an increased flow of molten rock from the Earth’s mantle, known as a mantle plume, which caused extensive volcanism throughout northeast Ireland, Greenland and western Scotland. Fissure-fed basaltic lava, as seen at the Giant’s Causeway in Northern Ireland, was the most common type of activity,

but a number of large central volcanoes

also formed e.g. at Carlingford and Slieve Gullion in Ireland. A key feature of these volcanoes was that they were short-lived and produced significant amounts of light-coloured felsic rhyolite and granite

magma, as well as dark mafic basalt. These rock types are at opposite ends of the magmatic compositional range and have very different physical properties, including their chemistry, colour, density and viscosity.

Typically, we would expect a magma

system to slowly evolve in composition from basalt to rhyolite through a process known as fractional crystallisation – where the composition of the basaltic parent magma progressively changes due to crystallisation and settling out of minerals such as olivine, pyroxene and hornblende. This process results in the formation of a continuous range of igneous rock compositions, with lots of basalt, medium amounts of intermediate andesite and eventually low volumes of rhyolite. In the BPIP, however, intermediate rocks are very rare, whilst rhyolite (and granite) is far more common than expected, a phenomenon known as ‘bimodal volcanism’.

Mafic-felsic bimodal volcanism was first recognised by the German chemist Robert Bunsen whilst on a geological excursion to Iceland in the mid-19th century, though these fundamentally different lava types have now been found together at sites across the planet. Crucially, the mixing of basalt and rhyolite in a volcano’s magma chamber is a major cause of violently explosive eruptions, such as those seen at Katla in Iceland. Despite this fact, in the 160 years since Bunsen’s observations no consensus has been reached on how bimodal volcanism actually originates.

The Carlingford Igneous Centre erupted 60 million years ago, but a new study published in Nature Communications reveals it has much to teach us about currently active volcanoes.

Geological terrane map of the British Isles showing the major geological divisions of the region and the Palaeogene volcanic centres. Pie charts give the proportion of mafic (black) and felsic (white) rocks exposed at each volcano. After Chew (2003), Geological Magazine, and Bell (1982), Igneous Rocks of the British Isles (Editor: Sutherland, D.S).

Mafic and felsic magmas are seen in close association throughout the Carlingford Igneous Centre. Intermediate rocks are almost completely absent, making this a bimodal volcanic centre. In this image mafic gabbro is intruded by felsic microgranite, forming a particular kind of intrusion breccia, known as ‘back-veining breccia’. These impressive features can be seen on the south-eastern part of the Barnavave ridge (J 176 947, J 176 088).

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Indeed, Bunsen himself is more famous for discovering the elements caesium and rubidium and inventing the Bunsen burner! Potential explanations that have been suggested for bimodal volcanism include liquid immiscibility (separation of basalt and rhyolite like oil and water), deep trapping of intermediate magmas below the volcanic edifice and chemical interaction of magmas with crustal rocks of a different composition.

The Carlingford Igneous Centre, Co. Louth, is a typical BPIP bimodal volcanic complex, with a large felsic microgranite ring-dyke (bell-shaped intrusion) cross cut by a mafic gabbro lopolith (dish-shaped intrusion). The final phase of intrusion was a swarm of basaltic cone-sheets. As the hot basaltic magma (>1200 °C) beneath Carlingford made its way from the mantle to the surface, it passed through the continental crust, which is 30 km thick in this part of Ireland. This crust is dominantly metasedimentary in origin, comprising mainly Silurian meta-siltstones. These meta-siltstones are rich in clay minerals and water and were easily metamorphosed by the hot magma, forming a hard, black rock, known as hornfels. In fact, the meta-siltstones were heated so much that they began to deform and the thermal aureole of the intrusions became partially molten. This crustal melt was then available to mix with the ascending mantle-derived magmas as they made their way through the crust.

Luckily, rocks from the crust and rocks from the mantle have characteristic chemical compositions. By analysing the isotopes of specific chemical elements, e.g. strontium, neodymium and lead, we can identify if mantle magmas have mixed with crustal melts – like geological DNA testing! By using these cutting-edge isotope analyses on the volcanic rocks from Carlingford, we detected that

crustal melts from the heated aureole were mixed into the ascending magmas, causing fundamental changes to the parent magma composition. These findings indicate that such large amounts of silica-rich molten crust were mixed into the mafic parent magma that it became granitic in composition. In fact, the felsic igneous rocks at Carlingford (e.g. the microgranite ring-dyke) were

Geological map of the Carlingford Igneous Centre, Co. Louth. Reproduced with permission from the Geological Survey of Ireland 1:100,000 scale bedrock geology map, Geological Survey of Ireland/Government of Ireland (2014).

Silurian meta-siltstone forms the majority of the crust around the Carlingford Igneous Centre. It is fine-grained and is rich in clay minerals. These rocks are very well exposed in the layby west of King John’s Castle in Carlingford, and on the adjacent shoreline (J 188 121).

The meta-siltstone was metamorphosed by the heat of the magma. Once it reached >750°C the meta-siltstone started to melt, seen here as pale veins. This melt collected and flowed, mixing with the intruding magma. The remaining baked rock is known as hornfels. Hornfels is best exposed across the slopes of Slieve Foye, below the contact with the main gabbro intrusion. It can be accessed via the Táin Way walking path, NW of the Slate Rock bend (J 175 115). The metamorphic grade (i.e. the degree of heating) increases as the gabbro intrusion is approached.


not formed by traditional fractional crystallisation at all, but by crustal melting.

Significantly, our team’s work has shown that the continental crust was most strongly involved during the early stages of activity at Carlingford. It appears that while a first flush of crustal melt was easy to extract, melting became increasingly difficult and granite formation eventually stalled. This is because not all minerals in crustal rocks melt at the same temperature, and while some components are readily incorporated into the magma, others are left behind and will never melt (known as ‘resite’). This research suggests that crustal melts are vital for the formation of rhyolite/granite magmas in continental volcanic systems, and that once the crust can no longer produce such melts, the volcanoes rapidly return to producing basalt – forming a bimodal rock suite, as we see at Carlingford, and throughout the BPIP. In fact, the wide variation in mafic-felsic rock proportions recorded across the BPIP (see regional map), is likely to be a direct function of the variable ability of different crustal rocks to melt. The higher the melting temperature of the

crust, the less granite that is likely to form. For example, the BPIP centres in northern Scotland have large volumes of mafic rocks, likely reflecting the high-grade gneissic basement in the region. This gneiss is more difficult to melt than to the clay-rich meta-siltstones at Carlingford, suggesting a key control on the resulting magmatism.

Importantly, the mafic and felsic rocks at Carlingford are not just separate intrusions, but preserve evidence of interaction and magma mixing. Basaltic injection into rhyolite/granitic magma chambers is known to be a key trigger of large, explosive volcanic eruptions and caldera collapse. This suggests that violent eruptions are likely to have occurred early in the lifetime of the Carlingford volcano, and while Carlingford has not posed any danger for 60 million years, it gives us a major insight into the processes that drive currently active volcanoes elsewhere on the planet.

This project was initiated at Trinity College Dublin by Prof Valentin Troll and Dr Fiona Meade, who are now based at Uppsala University (Sweden), and was supported by an international team of co-workers from institutions in the UK, Italy and the Netherlands. The research was funded by Science Foundation Ireland (SFI), the Irish Research Council for Science, Engineering and Technology (IRCSET) and the TEKNAT faculty at Uppsala University.

For more information please contact Prof Valentin Troll ([email protected]) or Dr Fiona Meade ([email protected]).

Meade, F.C., Troll, V.R., Ellam, R.M., Freda, C., Font, L., Donaldson, C.H., Klonowska, I. (2014) Bimodal magmatism produced by progressively inhibited crustal assimilation, Nature Communications, doi:10.1038/ncomms5199, (go.nature.com/XJg4xn). ◼

Mixing of basalt (dark) and rhyolite (light) magmas is preserved in the rocks at the Carlingford Igneous Centre. This process is known to lead to explosive volcanic eruptions, implying Carlingford was behaving like e.g. Krakatau or Vesuvius in its early stages! These mixing structures are seen in the vicinity of Cooley Castle Quarry (J 172 077), accessed using a rough track from the public road.

Carlingford has a beautifully exposed cone-sheet swarm; a series of inclined basaltic dykes which dip towards the centre of the complex (A). Some of these dykes are highly porphyritic (i.e. they have lots of big feldspar crystals)(B & C). Using a drill bit similar to a dental drill, we can sample individual crystal zones for chemical analyses. The crystal in C is only 1 mm across! The dark scars on this crystal show where core and rim samples have been collected for strontium isotope analyses. Like tree rings record the climate as they grow, crystal zones record changing conditions in the magma chamber and show that the influence of the crust on the Carlingford magma system decreased throughout the volcano’s lifetime. Well-exposed cone-sheets can be seen in road cuts at the King John’s Castle layby, just outside Carlingford village, and on the shore below (J 188 121). There is also an excellent example of a crystal-rich sheet just north of the Slate Rock (J 175 115).

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The sculpting of Scrabo Country By David KirkNo icy peaks reach for its skies, no water-falls thunder into deep ravines, few forest giants stride its slopes. Just a 500-foot hill and about 40 square miles of curvaceous pastoral landscape traced and explored by winding roads and clothed with the riches of one of the agriculturally most blessed parts of County Down.

Not in Scrabo Country the histrionics of the world’s wild and high places, just a beauty to be found in the diversities of a gentle land bursting with exuberant life in summer, slumbering in winter - and always patterned by the ever changing patchwork of pasture and tillage.

The scenery of this gentle landscape was given its final polish by the hands of man - but four hundred and thirty million years it took to build, shape and reshape, and finally gentle it.

It is the creation of all those endless millennia with their dramas of tectonic upheavals, of continents colliding and being torn apart again, of cold ocean depths, of high scorched deserts, of mountains of ice grinding away ancient rocks before melting away leaving deep rich soils where a new wave of life would come to spread and flourish.

Birthplace of farming?

It could be claimed in fact that Scrabo Country was the birthplace of farming in Ireland! The oldest known Neolithic site on the island, containing remains

of man’s first domesticated animals, was found beside Ringneill Quay, just six kilometres south of Scrabo Hill. It’s age was calculated at 6,200 years.

Finds of late Mesolithic flint implements at sites all round its shores reveal that for the previous 2000 years Strangford Lough had fed generations of hunter-gatherers who fished its rich and sheltered waters and hunted the deep woodlands that clothed the hilly lands around. The bay-filling inter-tidal mudflats that characterise the upper lough now would not then have been anything as extensive.

The soils the first farmers cleared and cultivated had been waiting for them for 7,000 years, left to blanket the eroded solid rock surfaces - stiff clays and fine sands dropped by the melting ice and moulded into little drumlin hills, and

stretches of well-drained gravels spread by the torrential rivers of glacial melt-water, especially along the Dundonald Gap. It was the end of the last period of glaciation, the Late Midlandian, which lasted from 23,000 to 13,000 years ago. The alignment of the drumlins show that the ice flowed from the direction of Lough Neagh, although there are some older drumlins left by earlier ice advancing southwards from Scotland.

But this was only the final phase (so far!) of nearly two million years of long glacial episodes with grinding ice sheets sometimes higher than the Mourne Mountains, alternating with warm spells such as we enjoy at present and which sculpted the solid bedrocks and created the setting and scenery of Scrabo Country.

The rock foundation

Scrabo Country lies between the arms of two ridges of the ancient hard rock that underlies most of County Down, the Silurian greywacke, once seabed of the ancient Iapetus Ocean that was turned to rock in the collision of the American and European continents 430 million years ago. Today’s broad Dundonald valley floored with Triassic sandstone hides a more dramatic one carved out of the Silurian rock - a borehole west of Scrabo Hill passed through more than 1,500 feet of sandstone and dolerite before reaching the greywacke!

And of course this Triassic sandstone is the rock virtually synonymous with Scrabo. Although it underlies the north end of Strangford Lough as far south Quarry in greywacke at Ballystockart, west of Comber

The rich drumlin landscape bequeathed by the Ice Age


as Greyabbey, the Dundonald Valley and the Lagan Valley from Whiteabbey to Lurgan it rarely appears above the layers of glacial till and soil and it is its ‘exposure’ from nearly a thousand years of quarrying Scrabo Hill for great building works that has given it iconic status.

It is not known how thick the sandstones were at their maximum but staining of the Silurian rock show that they once were almost as high as the Craigantlet hills, almost filling the Dundonald Valley.

They were formed at a time when for 40 million years Scrabo Country was located in the interior of the ‘super-continent’ Pangea, formed when all the earth’s land masses were fused together in one. It was at the present latitude of north Africa, a vast area of scorched desert building huge thicknesses of wind-blown sand from mountain ranges being eroded far away and occasionally swept by torrents that brought flash floods and even temporary lakes, evidence of which can be seen in the form of layers of mudstone. Life was sparse but hardy pre-dinosaur creatures, among them the archosaurs, obtained a living - and sometimes left their footprints in the sands, still preserved. Worm casts and those of fresh-water shrimps can also be found.

But it was 150 million years after the last of the sandstone layers were laid that the event happened without which there would have been no Scrabo (or much else of the north of Ireland’s most distinctive geology). As North America began to pull away from Europe, giving birth to the Atlantic Ocean, the same tectonic convulsions that created the granites of the Mourne Mountains and the Giant’s Causeway basalts were trying to force deep magma up through the thick sandstones too. It failed to reach the surface but the pressure split the rock between the horizontal layers deep down and surged in to harden as ‘sills’ of dolerite, some a few inches thick, others hundreds of feet.

One of these, an estimated 200 feet thick, but probably originally thicker, provided the armour plating that protected the sandstone below it from the grinding ice - it survived to form Scrabo Hill while all the rock around was eroded away.

Benefitting from a beautiful natural resource

Meanwhile the cutting, splitting and

removal of millions of cubic metres of its layered sandstone certainly changed the shape of Scrabo Hill - and it also shaped much of surrounding landscape created by man.

Steep faces of a beautiful white, pink and dark red stone, accessible, easily split, shaped and carved, was the stone worker’s dream, and over almost a thousand years it was eagerly ‘devoured’ for building homes and walls and creating some of the most elegant buildings man created for his gatherings and worship, not just in the neighbouring towns, villages and farms but across much of Ulster and as far away as Dublin and even, it is reputed, New York.

By the time quarrying had ended in the early 1960s an estimated 12 million cubic metres of rock had been cut away from the east and south sides of the hill, leaving more than a mile of almost vertical rock faces around 160

feet high in places. The intrepid walker, leaving the tracks (and negotiating some dense vegetation), can come across other small workings, possibly marking the first cuttings, which could have been from where stone was taken for the first known building works such as Grey Abbey (1193) or the twelfth century Holywood Friary.

Quarrying, which involved the splitting of stone into blocks by driving steel wedges - plugs and feathers - between the layers would have expanded to meet the needs of a growing population and local builders and farmers took full advantage of having such an ideal stone on their doorstep. It was appreciated elsewhere too, being carted to Dublin and elsewhere ‘in great abundance’ (William Montgomery, 1683). By the middle of the eighteenth century is had become an important industry with a number of companies operating quarries, the most important of which was the one opened

Stone from this quarry built much of the town spreading below

A fine example of a Scrabo sandstone building

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PEERING INTO THE DEPTHS!Peadar McArdle explainsThis article summarises the well-exposed rocks of the island of Fogo, off the northern coast of Newfoundland, which displays a composite granite-gabbro pluton with many features illustrating modern concepts of igneous intrusions.

The island of Fogo, an area of great natural beauty, lies off the north coast of the Canadian Province of Newfoundland and Labrador (Figure 1), and its population of 2,500 is distributed in several communities around its coastline. Traditionally reliant on cod fisheries since the mid-eighteenth century, a fishing moratorium imposed twenty years ago has had a negative and enduring impact on the island’s economy. Many young people now seek careers

elsewhere in Canada. Nevertheless the island has a resilient community that seeks to encourage tourism in harmony with its natural tranquillity. ◼

in 1826 by Robert Corry who went on to found the building supplies firm that still bears his family name.

But it was the industrial revolution of the mid-nineteenth century with the burgeoning construction of factories (such as the huge spinning mill built in Comber by the Andrews family), the building of churches and homes to cater for growing urban populations, and perhaps above all the arrival of the railways which transformed the transport of cut stone.

This really took extraction to a new level, with steam-powered mechanisation and a tramway linking the two quarries and down to a specially constructed railway siding at Newtownards.

The surge in production created hundreds of jobs with skills being passed down through generations (some families actually lived in the quarry complex). However changes in building technology, especially the use of concrete, the availability of cheaper sources of sandstone and also an increasing difficulty in cutting back into the hill safely led to a gradual decline during the 20th Century. Production had virtually ceased by the end of the Second World War and the South Quarry finally closed in 1966.

This feature is based on extracts from the author’s book ‘Scrabo Country’ due to be published this autumn by Cottage Publications. ◼

Location of Fogo Island

Fogo Map of rock formations

‘Climate science is settled’The idea that “Climate science is settled” runs through today’s popular and policy discussions. Unfortunately, that claim is misguided. It has not only distorted our public and policy debates on issues related to energy, greenhouse-gas emissions and the environment. But it also has inhibited the scientific and policy discussions that we need to have about our climate future. --Steven E. Koonin, The Wall Street Journal, 20 September 2014


Fogo, and all of Newfoundland, is part of the Appalachian Orogen, a major mountain-building event on a continental scale which resulted from the major plate collision event that marked the closure of the ancient Iapetus Ocean – an event also so important in Ireland. The line of closure, the Iapetus Suture, runs across central Newfoundland, with Fogo Island lying just to the southeast of it. The Leinster Granite occurs in an analogous position to the suture on this side of the Atlantic.

Fogo bedrock is dominated by the well-exposed Fogo Island Intrusion, a sheet-like composite intrusion emplaced along the bedding of its wall rocks (Figure 2). The sheet is 7km thick and consists of a relatively homogeneous granitic upper

half and a more heterogeneous gabbroic lower half. The granitic magma was produced by crustal anatexis caused by the hotter gabbroic magma as it ascended along fractures from the deeper mantle. Both magmas then moved upwards along such tectonic zones as the Dog Bay Line, a nearby dextral terrane boundary. The resulting magma chamber was assembled incrementally over a period that may have lasted as long as 20 million years. Feeder dykes are actually exposed beneath the intrusion, some being composite granite-gabbro bodies up to 60m wide. The entire intrusion has been tilted on its side so that now it is possible to examine its constituent parts by traversing from south to north across the island, thus going from its floor to its roof.

The Fogo Island Intrusion is emplaced in Silurian sediments of the Botwood Group. These are exposed above and below the intrusion itself as sandstones and siltstones which formed in a shallow marine environment (Figures 3 and 4). Some bedding surfaces have ripple marks and there is evidence of local slumping. There are also some turbidite sediments including a few rich in carbonate which may have poorly preserved fossils.

More dramatically, the wall rock sequence contains evidence of a major volcanic episode which was broadly contemporaneous with the intrusion itself. The volcanic products are best seen at Brimstone Head on the island’s north shore. This is a popular visitor destination because, as well as being a scenic location from which to

Siltstones and sandstones of the Botwood GroupSandstone bedding surface with ripple marks visible on the right-hand side

Bed of ash-fall tuff in the sediments near Brimstone Head

Dark grey gnimbrite with flattened lava fragments, Brimstone Head

Shoal Bay Granite Shoal Bay Granite with dark igneous rock inclusions

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view offshore icebergs and cetaceans (whales/dolphins/porpoises), it has been designated by the Flat Earth Society as one of the Earth’s four corners (see: www.itaylorresearch.com/ ). The earliest volcanic beds are sandy textured and characterised by coarse-grained angular lava fragments (Figure 5); there is some discussion as to whether they are ash-fall or lahar deposits. The fragments tend to stand out on weathered surfaces because they are mantled or partially replaced by diagenetic silica. The main eruption was significant in scale and very different in nature from earlier events. A huge glowing ash cloud was erupted by a

nearby volcano and deposited considerable thicknesses of very fine grained ash as ignimbrite. These ashes contain lava fragments which were still molten and have been squashed into very thin pancake-shaped fragments (Figure 6). No doubt the eruption was accompanied by clouds of volcanic gases which would have increased the acidity of nearby seawater. At the time, there were few if any land-based animals, otherwise the environmental disaster might have been on the scale of Pompeii.

The most widespread unit of the Fogo Island Intrusion is the Shoal Bay

Granite. It is medium to coarse grained and pink or grey in colour (Figure 7). It contains small phenocrysts of feldspar, green hornblende and brown biotite, but no muscovite. Inclusions of mafic igneous rock are common with rounded or angular outlines and no more than 10cm across (Figure 8). The granite has some small aplite veins as well as some felsite dykes which are considered the feeders for the Brimstone Head volcanic eruption. The felsite is similar in age and composition to the Shoal Bay Granite.

There are extensive coastal exposures of granite along the north coast of the

Rafts of sandstone in Shoal Bay Granite near its roof Compositional layering in the Tilting Layered Complex

Intrusion breccia, showing rafts of pale-grey sandstone which has become brecciated within, and veined by, gabbro

Dyke of fine-grained pink felsite traversing the Tilting Layered Complex

Seldom Gabbro (RHS) in contact with pale grey bedded sandstones

Intrusion breccia where Seldom Gabbro has invaded the footwall sediments


island. These become spectacular near the roof of the magma chamber where intrusion breccias are developed on a grand scale. Large rafts and inclusions of the wall rock sandstone have been stoped into the magma where they are chaotically arranged (Figure 9). The sandstone blocks themselves have been mildly metamorphosed by the granite and show biotite and poikiloblastic-textured spots which are possibly garnets. Intrusion breccias are best displayed on the foreshore at the recently-opened Fogo Island Inn. This is an up-market hotel of striking architecture and constructed in spruce timber (www.fogislandinn.ca/), which is attracting visitors in increasing numbers.

The gabbroic part of the Fogo Island Intrusion is most conveniently seen in the Tilting Layered Complex. The approach to Tilting town is signposted “Fáilte go Tilting” and the Irish tricolour flies proudly in its centre. My accent did not stand out among those of its inhabitants, many descended from Irish emigrants of the eighteenth and nineteenth centuries. Most came from the Waterford region to fish for cod on the continental shelf around the Grand Banks. The Tilting Layered Complex was first studied by the legendary Newfoundland geologist, Hank Williams (1934-2010), well known to Caledonian experts on this side of the Atlantic. It consists of layered mafic and ultramafic rocks, including gabbro, pyroxenite and norite. The layering occurs on varied scales (Figure 10) and it is possible to establish the presence of repeated magmatic pulses. There are some intrusion breccias formed where one rock-type has been invaded by another (Figure 11). In addition, there are also

some pegmatite veins composed of very coarse-grained hornblende and feldspar, as well as some prominent felsite dykes (Figure 12) which are considered to be feeders to the Brimstone volcanics.

The Seldom Gabbro forms the lower half of the Fogo Island Intruson and occurs extensively in the south and east of the island. The rocks range in composition between diorite and gabbro (Figure 13). There are extensive veins and dykes of granite which are identical to the Shoal Bay Granite. The rounded, bulbous contacts between this granite and the mafic rocks suggest that both were at least partially molten at the same time. The contact of the Seldom Gabbro with the underlying sandstones is exposed and is marked by extensive intrusion breccias (Figure 14). The gabbro displays layering just as at Tilting and some have graded compositions due to settling of the early-formed mineral grains. The intrusion accumulated incrementally over a significant time period. The contact between Seldom Gabbro and Shoal Bay Granite is a complex one and there is considerable interlayering of both rock types. Angular blocks of each appear in the other, but there is also evidence that both were molten or plastic at the same time.

Fogo displays the features of a very modern granite - a stratiform and composite sheet emplaced incrementally along the bedding of its wall rocks. It is considered that granitic and gabbroic magmas coexisted at the same time and that their density contrast has led to the observed separation of the resulting rock types, the lighter granite forming the upper part of the magma chamber. Fogo

is an excellent place to study the variety of relationships that can arise locally depending on the relative fluidity of the two magmas. Few intrusions expose such relationships so clearly, although I have been reminded at times of our own Carlingford Igneous Complex, which has granite stacked on top of gabbro. But Fogo’s layers have been helpfully tilted so that we can examine each part in turn on a north-south traverse across the island.

For more information on Fogo’s geology start with: Kerr, A. (2013) The Fogo process from a geologist’s perspective: A discussion of models and research problems. Current Research, Report 13-1. Newfoundland and Labrador Department of Natural Resources Geological Survey, pages 233-265. (http://www.nr.gov.nl.ca/nr/mines/geoscience/publications/currentresearch/2013/Kerr-Fogo_2013.pdf ).

My wife, Frances, took the photos (except numbers 15 and 16) while we lived on Fogo Island during Summer 2014. I participated in the Geologist-in-Residence Program of the Shorefast Foundation, a philanthropic organisation dedicated to rejuvenating the island’s economy. Its founder, Zita Cobb, is a woman of great vision and determination and it was she who established the Fogo Island Inn, as well as sponsoring an artists’ community. The Geologist-in-Residence Program, established in 2013, conducts outreach activities such as geological walks, lectures and research based on Fogo’s geology. Applications are now open for the 2015 season and more information can be found at: www.facebook.com/GeologyAtTheEdge. ◼

Hank Williams (1934-2010) pictured against a map of the entire Appalachian Orogen Joseph Beete Jukes (1811-1869)

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BETWEEN A ROCK & A CRYSTAL…and then you mention Professor Martin Feely and everybody will smile at you and of course they know him too! After over 30 years of great work at the National University of Ireland Galway (NUIG), Martin retires this November and although he promised that he won’t go anywhere and that he will keep working, he deserves special recognition for all he has achieved. Every Earth scientist around the country as well as the numerous collaborators and friends he met along the way, will join in to celebrate one of the greatest interpreters of local geology but most importantly a truly distinguished Irish scientist.

Martin graduated in Geology in 1973 in what was at the time University College Galway. In 1978 he completed a MSc at University College Dublin and was awarded his PhD at NUIG in 1982 with a thesis entitled “Geological, geochemical and geophysical studies on the Galway granite in the Costelloe/Inveran sector western Ireland’. He was appointed junior lecturer in Geology at NUIG in 1985, followed by a college lecturer appointment in 1994. In 1999, he became senior lecturer in Earth and Ocean Sciences. He became a professor in 2011 and soon after was appointed Deputy Head of Earth and Ocean Sciences.

Between 1997 and 2006 Martin was adjunct associate Professor of Earth Science at Boston University, USA and since 2006 has been adjunct Professor of Geological and Environmental

Sciences at James Madison University, Virginia, USA.

Martin has become a leading national expert on fluid inclusions. In 1990 he established the Geofluids Research Laboratory at NUIG. which has attracted significant funding from all over the world from both the public and private sectors. The Laboratory, which he directs, is the only one of its kind in Ireland and it attracts, on a regular basis, numerous researchers from overseas universities. Visitors from China, USA and Colombia, amongst others, have visited and very complimentary words have always been used to describe the level of research carried out. In 2004, he launched the Diploma in Scientific Studies in Gemmology, the first ever scientific Diploma offered by the Faculty of Science in NUIG. This course, which is run in collaboration with the Centre for Adult Learning and Professional Development at NUIG, is the only one of its kind available in Ireland. Citing the words used by a past student “what made the course experience all the more worthwhile was the care and dedication shown by the course lecturers” This care and dedication together with the desire of sharing his passion and his knowledge with the students made Martin an outstanding lecturer for which his past students will always be grateful..

Martin so far has authored/co-authored over 200 publications from pure research articles to field guides. Over the years he supervised and co-supervised to completion 27 postgraduates by research and 7 postdoctoral fellows. His research interests span from mineralogical and geochemical investigations to geofluids, igneous and metamorphic petrology, hydrothermal mineralization, gemmology and, currently, geomicrobiology. He has also always left some room in his schedule to carry out fieldwork, mainly in the West of Ireland and with particular emphasis on his beloved Connemara. Current research includes geological

evolution of the Caledonian-Appalachian Orogen and cross-Atlantic correlations with Newfoundland & North America, hydrocarbon and aqueous fluid inclusion studies in a variety of geological settings from around the world; 3-D visualization studies of geological landscapes; studies of the emplacement history of the Connemara granites; microbes in ancient and modern evaporite-hosted fluid inclusions. Today his active research and teaching has links with numerous institutions in Europe, India, USA, Brazil, Canada and China.

Martin remains very committed and enthusiastic about his ongoing research. This October he will start supervising, in collaboration with Microbiology, a PhD student who will be looking at microorganisms and biosignatures trapped in fluid incusions. Speaking on behalf of all the people who worked with him over the years, I thank him for what he taught us and for all the help and advice offered. Working with Martin over these past few years has been a blessing for me. I am fortunate to benefit from his personal wisdom and expertise every day and I will always applaud his integrity and try to follow his directions. As colleagues and friends, we have accomplished much together and we will still do…because there is a lot more to fight for and he is only retiring from this job; there must be a lot more to come.

Alessandra Costanzo (NUIG) ◼

Giant Beryl crystals, Albany, Maine, USA, photo taken in 1929 and an inspiration

Martin explaining deformational folding in the Connemara Marble

1999, 1st International Conference held by the Min. Soc of GB & Ireland outside the UK and organised by Martin


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HUBBLE, BUBBLE, TOIL…and you might just be inspired to learn more about our worldAt the annual BT Young Scientist Exhibition in Dublin young people, and some not so young, can be inspired by the science being done at primary as well as secondary level at our schools. This is where young people have a chance to show off their skills to the public. Do remember they have all been guided by wonderful teachers. Many schools attend, of course, not just to see what their friends have done but also to look at the exhibits of professional scientists from the public and the private sectors. This is where students can start to consider their future career paths.

We missed reporting last January’s exhibition in our spring issue but make up for that now. There were chemists playing with strange mixtures, physicists looking at aspects of gravity and biologists showing how algae might save the world. AND not least, with their feet

firmly on the ground, were the geologists.

The Geoscience Stand at the exhibition is always popular and very much a team effort led by the Geological Survey of Ireland (GSI), supported by the National Museum of Ireland, the Dublin Institute for Advanced Studies, the Institute of Hydrology, the Irish Geological Association and other volunteers. Matthew Parkes does a great job for the museum as well as promoting Earth Science Ireland. Activities on the stand include gold panning, minerals for living challenge, earthquake simulation, rocks of Ireland challenge, groundwater fun and other things.

The stand was busier than ever and there was lots of positive feedback, not least about the great variety of hands-on activities on the stand and the

enthusiasm of those working on it! The photographs we show are evidence.

In case you didn’t see it reported, the winners of the GSI Special Award were Tess Casasin-Sheridan & Aoife Doherty from Mary Immaculate Secondary School, Lisdoonvarna, for their project “Why are the beaches in Clare different colours?” We show a photograph of them with their teacher John Sims. They were worthy winners among the geoscience related projects.

And when you get this magazine the next annual event will be around the corner. We will report on it again in the spring but if you get a chance to go the quality and enthusiasm of everyone involved might surprise – and inspire - you.

Editor, with thanks to Matthew Parkes ◼

Issue 15 39

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