VOLUME 48 . MARCH 2017

INSIDE:

Visit of the minister to the Council for Geoscience I 1Mahlako Mathabatha

Airborne geochemical mapping in the Mpumalanga Province I 2Ndivhuwo Cecilia Mukosi/Valerie Nxumalo/Eliah Mulovhedzi

Passive treatment technology for long-term mine water management I 4Obed Novhe

Nigeria–South Africa joint cooperati on: second session of technical meeti ng in Nigeria I 5Refi lwe Shelembe

Geoscienti sts allay fears of local community! I 6Pieter Bosch/Neo Moabi

Reviving the photographic history of the CGS I 7Rehan Opperman

Laboratory Services – Mineralogy Secti on I 8

Visit of the minister to the Council for Geoscience

On Thursday, 12 January 2017, the Minister of Mineral Resources, the Honourable Mr Mosebenzi Zwane (MP), accompanied by the Director-General, Mr David Msiza, and his delegation, visited the head offi ce of the Council for Geoscience in Pretoria. The acting CEO, Mr Mosa Mabuza, welcomed the ministerial delegation and Executive Management in the auditorium and called upon Mr Msiza to introduce the minister to the CGS employees.

In his address, the minister acknowledged the role the Council for Geoscience plays in the mandate of the Department of Mineral Resources to achieve its goals of transformation, economic growth and investment attraction. He emphasised the work of the organisation as key to the research and development initiatives of the country. One of the mandates of the Council for Geoscience is mapping and he urged the scientists to continue to work hard at remaining a leader in geomapping on the continent and worldwide. The minister further recognised the long-service employees who have been working tirelessly with pride and distinction to achieve the goals of the organisation.

The honourable minister and his delegation took the time to visit the facilities of the CGS laboratory. Mr Supi Tlowana, the Laboratory Services Manager, presented an overview of the activities of the laboratory. The delegation visited the XRF and chemistry and mineralogy sections and Mr Tlowana briefl y explained the technology of the following instruments to the delegation:

• The new wavelength dispersive XRF spectrometer for elemental analysis in solid samples.

• Three ICP-MS instruments for ultra-trace liquid sample analysis under clean laboratory conditions.

• The new ICP-OES used for trace liquid sample analysis.

• The SEM used for mineralogy identifi cation.

• The X-ray diffractometer, an instrument used for the qualitative and semiquantitative identifi cation of minerals.

Mr Tlowana acknowledged the funding allocated to the laboratory recapitalisation project as this has enabled the Council for Geoscience to procure state-of-the-art instruments and equipment which will

Minister Mosebenzi Zwane, ministerial delegation and the CGS Executive Management.

I GeoClips2

For more information contact:Mahlako MathabathaGo to Market+27 (0)12 841 1220mmathabatha@geoscience.org.zaMs Michelle Grobbelaar, microzonation project manager, explaining the functions of the seismograph network

screens to the ministerial delegation.

Airborne geochemical mapping in the Mpumalanga Province

improve the quality of the outputs and replace obsolete instruments.

Furthermore, the Minister visited the CGS seismograph network screens which are situated on the sixth fl oor of the main building. Ms Michelle Grobbelaar, the manager of the microzonation project, explained how the screens can display ground movement, registered by the seismograph stations installed both nationally and in neighbouring countries. The monitors can also display the automatically calculated time, location and size of the tremors. She pointed out the mining regions in South Africa where the Council for Geoscience has installed a denser network of monitoring stations (Klerksdorp, Carletonville and Johannesburg) that will be used for further research into mine safety. She concluded by mentioning the various international networks to which the Council for Geoscience contributes data (AfricaArray, CTBTO and IOTWS) and the benefi ts of these networks to the organisation and the country.

Welcoming address by the acting CEO, Mr Mosa Mabuza, in the auditorium.

The Sabie–Barberton geochemical mapping project in the Mpumalanga Province is a continuation of the mid-term expenditure framework project mandated by National Treasury through the Department of Mineral Resources (DMR) for mineral target generation in South Africa. The objectives of this helicopter-based geochemical mapping project are:

(a) To stimulate exploration and mining investment in the mineral and energy sectors by generating mineral potential targets.

(b) To aid in the acquisition of exploration geochemistry data for the generation

of mineral potential target areas and the establishment of an updated geochemical database, as this will assist in providing a variety of geoscientifi c solutions.

The study area is situated in the eastern edge of the Kaapvaal Craton in the Barberton Greenstone Belt (BGB) and in the Sabie–Pilgrim’s Rest goldfi eld. The BGB is one of the famous greenstone belts in the world, with ages ranging between 3.5 and 3.2 Ga. The BGB is associated with gold mineralisation and, as such, there are several active and dormant gold mines in the area. The study area is mainly composed

of a volcanosedimentary succession named the Swaziland Supergroup and is surrounded by Archaean granites and gneisses as well as some formations of the Transvaal Supergroup. The Swaziland Supergroup consists of (a) the Onverwacht Group that is composed largely of mafi c and ultramafi c volcanic rocks; (b) the Fig Tree Group that consists of successions of greywacke, shale, chert and siliceous fragmental volcanics, and (c) the Moodies Group that is composed mainly of lithic, feldspathic and quartzose sandstone, conglomerate, minor amounts of siltstone and shale and thin units of basalt, jasper and magnetite-bearing shale. These

GeoClips I 3Geoclips - Volume 48 - March 2017

a. A team of geologists, geochemists and technicians were involved in consultations with farmers, landowners and stakeholders. Top left to right — Mr S. Zondi,

Ms N.C. Mukosi, Mr R. Netshitungulwana, Mr J. Mokoatedi and Mr J. Radebe. Bottom left to right — Mr A.E. Mulovhedzi, Ms N. Mashale, Mr S. Hlatshwayo and Ms

V. Nxumalo. b. Consultations with landowners is a necessary task for geological or geochemical work. c. Sabie–Barberton team at the Mbombela airfi eld: Top left to right:

Mr Z. Bubani, Mr D. Mathabatha, Ms L. Madiba, Mr T. Ntikang, Mr F. Bornman, Middle row: Mr A. Rikhotso, Mr R. Lusunzi, Mr M. Malatji, Mr K. Sekiba, Mr S. Cele, Mr

J.P. Havenga, Ms N.C. Mukosi, Bottom row: Mr J. Mokoatedi, Mr M. Kobolo, Mr D. Nxumalo and Mr M. Breakfast. d. Mountains of the Barberton Greenstone Belt along

the R40 to Barberton/Mbombela. e. ZS-RZJ helicopter in action. The area is very mountainous and densely vegetated, which makes the operation challenging. f. Technical

offi cer sampling the soil.

a

c

e

b

f

d

I GeoClips4

groups are further subdivided into formations.

The Sabie–Pilgrim’s Rest goldfi eld mainly includes a sedimentary succession of the Transvaal Supergroup. This succession occurs along the preserved eastern margin of the Proterozoic basin. The rocks of the Transvaal Supergroup comprise the chemical sediments of the Malmani Subgroup at the base, which are overlain by mostly siliciclastic rocks of the Pretoria Group. The base of the Malmani Subgroup consists of the lowermost Black Reef Formation which is widespread and marks the regional unconformity. The carbonate rock units of the Chuniespoort Group and Malmani Subgroup in the Sabie–Pilgrim's Rest goldfi eld are the principal rocks to host gold mineralisation.

Generally, the economy of the Mpumulanga Province is based on agriculture, tourism and mining. Therefore, prior to conducting the airborne soil sampling survey, consultation sessions were conducted by senior geologists and technical offi cers in July 2016 with farmers, farmer associations, land owners, public and private entities such as SAPPI (South African Pulp and Paper Industries) and the Mpumalanga Tourism and Parks Agency (MTPA), and representatives of the gold mining industry, to mention a

few. Furthermore, communication was extended to community leaders and traditional leaders in the study area. Consequently, this led to the smooth running of the operations in the fi eld. In areas where there is wildlife, a team consisting of geologists and technical offi cers were deployed to focus on foot sampling since conservation is important to the province. Thus far, over 50 % of the airborne soil survey has been completed in the area.

Each project comes with its own challenges. In this particular project the main challenges have been the terrain, which is very mountainous with dense vegetation and forestry. Furthermore, bad weather (rain, strong wind, fog and mist) has led to delays in the operations. Technical challenges include the main and tail rotor blades tape of the helicopter becoming worn out and scheduled and unscheduled maintenance taking longer than expected.

The project team wishes to thank the DMR for fi nancial support and BAC Helicopters for their services. The Sabie–Barberton team consists of: Geochemistry Task Leader - Mr R. Netshitungulwana; Project Task Leader - Mr A.E. Mulovhedzi; Field Supervisor(s) - Ms N. Mashale, Mr S. Hlatshwayo, Mr T. Ntikang and Ms N.C. Mukosi; Geologists - Mr M. Breakfast, Mr R.

Lusunzi, Mr M. Kobola, Ms V. Nxumalo, Ms M. Modiba, Mr T. Mofokeng, Mr R. Chauke, Mr M. Malatji, Mr A. Rikhotso, Mr L. Chiya and Ms T. Mudau; Technical Offi cers - Mr J. Radebe, Mr J. Mokoatedi, Mr S. Zondi, Mr M. Mudau, Ms L. Madiba, Mr D. Nxumalo, Mr D. Mathabatha, Mr Z. Bubani, Mr T. Thiba, Mr B. Makofane, Mr I. Chuene, Mr R. Ngobeni, Mr S. Cele, Mr K. Mogowe and Mr K. Masemola. A special word of thanks goes to the sample transportation team led by Mr D. Makgate and to the senior level team who assisted towards the success of the sampling phase of the project — Dr A. Billay, Dr S. Foya, Mr J.H. Elsenbroek, Mr J. van der Merwe and Mr J.P. Hunt.

For more information contact:Ndivhuwo Cecilia MukosiMapping Geology+27(0)15 295 3471cmukosi@geoscience.org.za

Valerie NxumaloEconomic Geology+27 (0)12 841 1511vnxumalo@geoscience.org.za

Eliah Mulovhedzi (Project Task Leader)Economic Geology+27 (0)12 841 1408emulovhedzi@geoscience.org.za

Passive treatment technology for long-term mine water managementMany of the abandoned coal and metal mines in South Africa generate acid mine drainage and over the years this has contributed to the pollution of water resources. Owing to the nature of past legislation, the South African Government has inherited the environmental liabilities of most of these sites and hence there is an urgent need to develop long-term sustainable remediation or management solutions.

Passive treatment is a technology of choice for the long-term remediation of polluted mine water at abandoned

mine sites in many parts of the world (e.g. the USA and UK). The technology is considered to be inexpensive since it relies on natural processes and eliminates the use of expensive chemicals, electricity and manpower. However, applicability of this method in South Africa is limited.

To contribute towards the development of sustainable mine water management solutions in South Africa, the Council for Geoscience has constructed a pilot passive treatment system consisting of integrated anaerobic and aerobic units to treat acid mine drainage discharging

from an abandoned underground coal mine in Carolina, Mpumalanga.

Two anaerobic units were constructed in 1 m3 intermediate bulk containers using limestone (containing at least 85 % CaCO3) and organic substrate (a mixture of cow manure, compost and chicken manure). The pilot plant was operated for 15 months, with regular monitoring of the water quality. Water parameters, such as pH, redox, EC and the alkalinity of the infl uents and effl uents were analysed daily for the fi rst three months and thereafter on a weekly basis. Water samples were also collected

GeoClips I 5Geoclips - Volume 48 - March 2017

and analysed by means of ICP-MS and IC analytical techniques. Precipitates were collected after 12 months of operation, and analysed for mineralogical compositions using X-ray diffraction and scanning electron microscopy.

During the fi rst six months of operation, the pilot plant has successfully neutralised the water and substantially removed contaminants such as Fe, Al, Co, Zn, Ni, As, Pb and V, but has achieved only minimal SO4 reduction (only a 30 % removal rate was achieved). Thereafter, there has been a decrease in treated water quality over time, and this was largely due to clogging of and/or depletion in the treatment materials.

For more information contact:Obed NovheSustainable Resources and Environment+27 (0)12 841 1387onovhe@geoscience.org.za

pH of the infl ow and outfl ow water in the passive treatment system.Reducing and alkalinity producing system (RAPS) (anaerobic units) and oxidation

pond (aerobic unit).

Metals were removed as sulfi des in the anaerobic units and as hydroxides in the aerobic units.

The study demonstrated that passive treatment technology can be a long-term sustainable solution for the remediation of polluted mine water at abandoned mine sites in South Africa, depending on site-specifi c characteristics such as fl ow rates, land availability and topography. The geochemical mechanism of passive treatment of polluted mine water is a complex process, comprising a number of reactions that occur under different pH and redox conditions. Hence, to achieve optimum long-term remediation of polluted mine water in

South African abandoned mine sites, an integrated passive treatment approach is recommended. However, further work is ongoing to evaluate the performance of the system in view of optimising the design criteria and ensuring improved effi ciency and longevity.

Nigeria–South Africa joint cooperation: second session of technical meeting in Nigeria A technical meeting was held from 16 to 20 January 2017 in Abuja, Nigeria, between various counterpart departments and science councils of the Federal Republic of Nigeria (FRN) and the Republic of South Africa (RSA). This technical meeting follows a Memorandum of Understanding (MoU) which was authorised in 2013 by the RSA and the FRN.

Various technical working groups were formed through the MoU to address the areas of cooperation, including geology, regulatory frameworks, licensing, mineral processing, metallurgy, capacity building and artisanal and small-scale mining for investment promotion. The acting CEO

of the Council for Geoscience, Mr Mosa Mabuza, and Ms Refi lwe Shelembe attended the technical meeting.

The MoU was re-activated at the end of 2015 through the formulation of a two-year Implementation Plan (2017– 2018) which was forged between the South African Department of Mineral Resources (and its entities including the Council for Geoscience) and the Nigerian Ministry of Mines and Steel Development and its entities. Through this two-year implementation plan, the Council for Geoscience will work together with the Nigerian Geological Survey Agency (NGSA) on issues including agriculture, energy,

advancement of scientifi c knowledge generation and capacity building with the economic development of South Africa and Nigeria as the main objective. In order to direct and focus the prospects of development opportunities in Nigeria, the following tasks in terms of which the two science councils will work together are considered:

Food security/agricultural developmentFor sustainability, it is important for any country, especially an African country, to have concrete plans for food security to promote the welfare of its citizens. Food security policies are largely linked to agricultural policies and, in many African

RAPS 1

RAPS 2 Oxidation pond

I GeoClips6

countries, there is a large gap between the policies and the actualisation of these policies. Like other countries, Nigeria and South Africa are assessing the robustness of their food security plans. Although Nigeria has conducted nationwide agromineral mapping on phosphate, limestone, gypsum and feldspar, the country is seeking to fortify its food security. As a start, the Council for Geoscience and the NGSA will evaluate the extent of mineralisation within three identifi ed sedimentary basins in Nigeria for fertiliser production. The assessment of the quantity and quality of mineral input and the related existing datasets will be followed by a feasibility study to establish a fertiliser plant proximal to the source area.

Energy securityLike South Africa, Nigeria is seeking to improve and diversify its energy mix and, for this reason, the FRN has set a target of 30 % (from 0 %) for its energy production from coal sources. The Council for Geoscience and the NGSA have agreed to work together on evaluating the extent of the

coalfi elds in Nigeria to inform prospects of development and to conduct a feasibility study to establish a briquette manufacturing plant(s) to replace the use of wood for energy requirements in rural Nigeria so as to reduce deforestation. It is envisaged that the work will be carried out in line with the national energy objectives as well as the upcoming Investment Promotion conference to be held in Nigeria.

Packaging of existing geoscientifi c informationPreliminary evaluation of the various datasets and a map output is essential for gap analyses. This will allow for the strategic integration of the existing geoscientifi c datasets and the promotion of the existing geodata into marketable forms which will be used for investment promotion. This is fundamental for both countries.

Human and infrastructure capacity building (*together with Mintek)Professional capital (knowledge and skills) exchange between Nigeria and South Africa is a vital and inherent

For more information contact:Refi lwe ShelembeMapping Geology +27 (0)12 841 1098rshelembe@geoscience.org.za

aspect of this agreement and will include the following:

- *Formulate a laboratory training programme for counterpart scientists

- Accommodate one or two early-career counterpart scientists in some of the Council for Geoscience fi eld training programmes

- *Assist to formulate standard operating procedures and source reference standards for laboratory centres

- *Assist to formulate maintenance plan development in respect of analytical equipment

- *Assistance with laboratory certifi cation application.

The Council for Geoscience is proud to work together with another African country for the upliftment of African communities. Together we can “Power Africa”.

Geoscientists allay fears of local community!Around 16:00 on a sunny afternoon early last year, the local community of the Dikgopheng Section of Mokuruwenyane Village, about 50 km northeast of Lephalale, was rocked by explosions and strange sounds. Upon the arrival of the police, another explosion was heard, causing the police to depart hastily. The Waterberg District Disaster Management Centre contacted Ms Michelle Grobbelaar to investigate the event, but Mr Ian Saunders of the Seismology Competency could fi nd no records of a seismic disturbance at that time and place.

Mr Pieter Bosch and Mr Neo Moabi were requested to investigate the event further and soon afterwards they visited the area. An “Indaba” with representatives of the Waterberg District Disaster Management Centre, local municipality and the residents was held promptly under the shade of a big acacia tree.

The “culprit” appeared to be a low-lying granitic dome which crops out along a portion of a resident’s yard and in the neighbouring fi eld. An investigation of the granite revealed the presence of large fl at slabs of granite with fresh dislocated surfaces. It became apparent that a weathering process known as exfoliation may explain the strange behaviour of the rocks. During the process of exfoliation, individual layers of granite gradually “peal” from the outer layers of especially igneous rocks. However, it was established that the explosions took place during the exceptionally prolonged heat wave that had engulfed large portions of the country at the time and the locals confi rmed that it had been especially hot on the day of the incident. It is therefore highly likely that the granitic dome had been heated abnormally by the warm conditions and hot rays of the sun which had resulted in above normal expansion of the granite. The outer layers of the

granite could therefore have “popped off” when the stresses overcame the strength of the rock portions that were holding it. When this happened, the outer skins were ripped off disturbing the air pressure. This resulted in loud bangs and a surfi cial shock wave that produced dust and a light breeze. The strange “moaning” sounds may have been caused by the rubbing of the different layers against each other.

Research on the Internet revealed a similar phenomenon that was recorded on video where exfoliating granite rock had “popped” after baking in the hot desert sun of the Sierra Nevada. Similar slabs of rock at granitic and other igneous rocks outcrops show that this kind of event probably takes place often in nature, although it is seldom recorded. However, owing to the very local nature of the occurrence, fortunately no instances of harm to people and animals were recorded. Exfoliation indeed

GeoClips I 7Geoclips - Volume 48 - March 2017

sometimes causes damage to property, for example a dam started to leak along its foundations owing to this weathering process. Slabs of slate or sandstone often explode when they are thrown into a fi re or are used as a barbeque griddle

For more information contact:Pieter Bosch/Neo MoabiGeoscience Mapping +27 (0)12 841 1350/1087pbosch@geoscience.org.zanmoabi@geoscience.org.za

Pieter Bosch explains the process of exfoliation and

thermal expansion to the residents, members of the

community and members of the Waterberg District

Disaster Management Centre.

View of slabs of granite that had been dislocated from

the main granite dome.

The slabs of granite revealed fresh underlying rock

when removed.

Neo Moabi investigates the slabs of granite that had

been ejected from the dome.

support and this practice may well lead to injury.

It is our sincere hope that the fears of the local community were laid to rest and that they slept much better after our visit!

Reviving the photographic history of the CGSSome time ago, a client requested digital images of a few old glass negatives kept in the archives of the Council for Geoscience. Converting old glass negatives into a digital format takes effort and is a fragile and costly process. Ms Estelle van Tonder, who is in charge of

the archives, asked Mr Rehan Opperman to assist with the delicate process of converting the glass negatives into digital format.

As a test run, a few negatives of approximately postcard size were

Barberton (ca 1905–1908). Looking southeast

from Hospital Hill (Google Earth 25°46'50.56"S,

31°2'31.13"E).

illuminated using a light table similar to the tables used by cartographers to draw maps. A DSLR camera with a tripod, remote trigger and a prime 50 mm lens was used to take photographs of the glass negatives.

Using IrfanView freeware downloaded from the Internet, the photos were cropped and limited editing was done. The main challenge was to convert the negative images into positives. To accomplish this, the “negative (invert image)” function of IrfanView was used on the principle that converting a negative image into a negative image results in a positive image.

Acceptable results were obtained and after forfeiting a couple of lunch breaks, the rest of the glass negatives (about 65 in total) and some old photographs were converted to digital images.

Old bridge across the Komati River likely taken from

the weir just upstream from the bridge (Google Earth

26°2'9.96"S, 30°59'51.50"E).

If you are not on our mailing list and you would like to receive a copy of GEOclips, please send an e-mail to:Mahlatse Mononela, Go to Market, mmononela@geoscience.org.za

Private Bag X112, Pretoria 0001, South Africa / 280 Pretoria Street, Silverton, PretoriaTel: +27 (0)12 841 1911 / Fax: +27 (0)12 841 1221 / www.geoscience.org.za

For more information contact:Rehan OppermanMineral Resources Development+27 (0)12 841 1121opperman@geoscience.org.za

Unfortunately, some of the negatives had deteriorated beyond repair, but, as can be seen from the photos, there were some real gems. It would appear that most of the photographs could have been taken by the well-known Dr A.L. Hall as some of the photos were recognised

Offi cial transport of the CGS. Field camp set-up.

Council for Geoscience hosted some well-known overseas geologists on a nine-month fi eldwork stint throughout South Africa and Namibia. Results from this expedition (especially the visits to the Bushveld Igneous Complex) apparently played a major role in the decision to host the 1929 IGC in South Africa. If time allows, it is hoped that these photographs will also be converted into digital format.

from old publications of the Council for Geoscience. The images probably date from 1905 to 1912.

There are also some substantial photo albums containing pictures of the 1922 Shaler Memorial expedition when the

Laboratory ServicesThe Mineralogy Section of the laboratory recently acquired a high-resolution digital microscope. The Leica DVM6 microscope offers versatile functionality for manual or automated imaging. The instrument is equipped with a tilting stand, combined motorised precision xy-stage with manual coarse positioning and motorised focus for automatic 3D image stacking, allowing for sharp multifocus images, 3D analysis and high-resolution scans of larger areas. The microscope can accommodate various sample types and sizes up to 2 kg with a stage travel range of 60 mm. The software package includes image capturing and image management, 2D imaging, measurements and annotations, images with high depths of fi eld, an autofocus function, multifocus images with 3D view and 3D inspection and measurement, and the ability to create xy-panorama images in 2D and 3D.

For more information contact: laboratory@geoscience.org.za

Mineralogy Section