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Branch Organiser Cliff Probert 21 Dunscore Brae Hamilton ML3 9DH

west.scotland@ougs.orgUU

Post Exam Weekend trip to Arran

Leader Dr NeilClark

Accommodation Kilmory Public Hall Bunkhouse

Contact: west.scotland@ougs.org

Treasurer

Hammy Corrance

36 Bensley Avenue Girdle Toll

Ayrshire KA11 1AJ 01294 212801

Branch Web Site:

http://ougs.org.

ERRATIx

OPEN UNIVERSITY GEOLOGICAL SOCIETY ~ WEST OF SCOTLAND BRANCH ~ NEWSLETTER

October 2012

West is Best

Ed’s ramblings

Again I have to apologise for a large gap in the newsletter copies.

Lame excuse but this summer has been extraordinarily busy for me. Instead of trawling around with my nose on rocks, I was preparing and being involved in the most exciting sports competitions around. Namely the Olympic and Paralympic Games in London. As a technical official, I had some preparatory competitions as well as the main ones to keep me occupied and was privileged to be involved duringf the most exciting few weeks of my life.

While there, I was quizzed about some of the stones used to build some of the blocks of flats and walls in the picturesque Olympic Village. However I had to disappoint the questioners as the building stones were all man-made,although some were spectacular in their likeness to natural conglomerates, polished igneous ‘building front-ite’ and fossil-filled limestones.

Now back to the real business.....I only have one trip to report on since no one else has offered any reports although I am sure many of you out there will have some stories to share of sites visited and interesting rocks pored over. Please feel free to share your experiences and photographs with fellow members.

Finally, it would help the Society’s financial position if more members were willing to take newsletters by emai. Please think seriously about opting for electronic versions of Erratix. You will already havebeen asked to take the OUGS newsletter electronically.

Joyce

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WHERE DO WE GO FROM HERE? Branch field trips have been few and far between this summer. I am sure Cliff and Stuart would be happy to hear from members where they would like to visit. Remember that anyone with a good idea or locality close to them can put forward ideas for trips, be it day visits or weekends. We have had Kintail (and Ayrshire with the Easties) this year so far with Arran looming. What about somewhere in the Central belt, although the Glasgow Society does their area very well? Are members local to Glasgow dipping into lectures and visits …and hopefully formally joining those fondly referred to by Maggie as the ‘Glasgow Crowd’. Have a think about it and come to the AGM with ideas and proposals. AYRSHIRE TRIP The East of Scotland Branch trip to Ayrshire was well attended by members of West Scotland, being in easy reach of many of us. The trip was led by that fount of knowledge, Professor Brian Upton. Meeting on a spare piece of ground in Darvel, we were assured by a passing bus driver that we could leave our cars there as long as he had room to spin his bus round. We received our directions from Brian and headed off to our first locality, Loudon Hill – leaving just two vehicles to the bus driver’s mercy.

BRANCH ORGANISER’S NOTE

Hello Everyone I hope folks have been able to enjoy some of the early autumn sunshine that we have had recently. A few members from the West of Scotland attended the East of Scotland field trip to East Ayrshire lead by Prof. Brian Upton of Edinburgh University. This was my first time in this area and so I had a very interesting day learning about some of the volcanic intrusions in the area. Many thanks to Stuart Swales for organising the day. Next year’s field trip to Inchnadamph is now fully booked, but it is not unusual for somebody to withdraw from trips and so there will be a waiting list for anybody who is interested in going on the trip. At around the same time as the Inchnadamph trip there will be a field trip to Arran led by The OUGS President Dr Nick Rogers which may be of interest to members. Details of the Arran trip are on the OUGS website and more information can be obtained from the organiser Chris Arkwright (events@ougs.org). .

Cliff

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Loudon Hill (Photo J Rammell)

Sandstone cliffs (and Prof Upton’s hat) (Photo J Rammell)

Weathering on boulder (Photo M Perkins)

After a short briefing in a small quarry, we set off up Loudon Hill which is the remnants of a phonolitic trachyte volcanic plug rising dramatically out of the surrounding farmland. The plug was estimated to have had 500m to 900m of cover eroded through time. The whole area has been peppered in the past by numerous small volcanoes and the plug may be the feeder conduit. Although contemporaneous with the likes of North Berwick Law in the East, research shows they are not from the same deep crustal origin. Reaching the side of the scree slope we examined the fine

grained igneous loose rocks but had difficulty identifying any minerals. On our return, we spotted a fallen boulder with some unusual weathering patterns, These were circular with lines radiating outwards, The explanation was poorly formed columnar jointing. Returning to the cars, we moved to the South Side of the plug, where we had a better view of the plug and what was described as some columnar jointing but did not have time to climb across to look at it close up. While there, we used the car park to have a short lunch break and read the information board that unfortunately did not describe the geology but the historical significance of the area as the scene of battles against the English won by William Wallace and Robert Bruce a mere10 years apart.

From there we travelled to Locality 2 to view the Mauchline sandstones in the gorge of the river Ayr, laid down at the Permian/Carboniferous boundary. Brian informed us that these sandstones are the youngest sedimentary rocks in the Midland Valley – on the mainland that is, – younger ones outcropping on Arran. We walked to a very steep-sided disused quarry which has provided the building materials for many local buildings as well as some in the Edinburgh and Glasgow areas. On the vegetation covered sides, we could see the bedding structures clearly. Further along we were able to look closely at samples and under the hand lens it was obvious that the grains were well-sorted and aeolian in origin. We could distinguish coarser layers on what appeared to be the bedding surfaces.

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Lugar Sill (Photo J Rammell)

Howford Bridge Sill (Photo J Rammell)

We walked on upstream along the road and over old Howford Bridge to view a 30m thick sill. At first we thought it was just two 30cm thick sills either side of a larger, massive structure, but we were informed that it was all one alkali dolerite sill. We were unable to examine the sill closely because it was on the opposite bank of a river in spate. However Brian, in his younger days, had scrambled down from the newer bridge to obtain samples of the upper surface of the sill and was able to let us examine his excavations to support the story. The story is that the coarse-grained syenite

sill was intruded into the sandstones and the two ‘outer’ layers are the most differentiated part of the mix ‘squeezed’ out of the mix to the edges. We then drove south to Lugar and, after not a little confusion over where to find the best parking spot, walked along the Lugar Water to view the Lugar sill. This is a classic example of a multiple intrusion.’ The magma body was presumed to have been compositionally stratified, with more evolved compositions at the top and the most primitive compositions at the bottom of the magma chamber. The sill was then fed in successive pulses, emptying the chamber from the top downwards on five different occasions, giving nine ‘layers’, the most primitive of these being the last to be intruded’ This has been proved by a bore having been taken through the 49m sill. Again the river level was too high for us to examine the sill itself or river boulders but again Brian did his Blue Peter act and had brought samples taken previously from the area. The samples showed the different compositions of the pulses with abundant phenocrysts which we had fun trying to identify. The most spectacular were the cm-long needle-like amphiboles of the kaersutite from the most differentiated part of the sill.. By the time we walked back to the vehicles, the light was about to go and we agreed it had been a very worthwhile day out, especially since the rain had managed to stay away with only one shower making us put our hoods up! Brian was thanked by Stuart in the normal OUGS fashion and we all parted company to find our way home.

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FUTURE EVENTS for 2012/13 Talks………….

………..and Events

Contacts Cliff Probert: west.scotland@ougs.org Stuart Swales: 01887 840377; OUGS: http://ougs.org east.scotland@ougs.org (AGS) Aberdeen Geological Society . Lectures – Thursdays in the Meston Building, University of Aberdeen, Old Aberdeen at 6.30 pm. For further details see UU Uwww.aberdeengeolsoc.co.uk

(EGS) Edinburgh Geological Society . Lectures are held Wednesdays, 7.30 pm in the Hutton Lecture Theatre in the Grant Institute of Geology, on the University of Edinburgh's King's Buildings campus. For details of field trips please contact the EGS Excursions Secretary, e-mail excursions@edinburghgeolsoc.orgT. For further details see www.edinburghgeolsoc.org. (GSG) Geological Society of Glasgow . Lectures are held Thursdays, 7.30 pm in the Gregory Building, Lilybank Gardens, University of Glasgow. For details of lectures and field trips please contact secretary, Dr Iain Allison, geolsocglas@uk2.net. UUUUUUor Margaret Donnelly, 0141 334 0559, mmdonn@btopenworld.comUU. For further details see Uwww.geologyglasgow.org.uk

(HGS) Highland Geological Society . Lectures are held at 7.15 pm in the Fairways Leisure Centre, Castle Heather, Inverness. For details of events please contact Alison Wright, a.j.wright00@aberdeen.ac.uk.

Date Organisation Details Time Location

Nov 8th Geological Society of Glasgow

Ice streams in the British (Scottish) ice sheet: Theory and observations from off-shore and offshore Dr Tom Bradwell British Geological Survey, Edinburgh

7.30 pm Glasgow University Gregory Building, Lilybank Gardens,

Dec 13th Geological Society of Glasgow

Annual General Meeting Presidential Address by outgoing President’ Miss Margaret Donnelly

7.30 pm Glasgow University Gregory Building, Lilybank Gardens,

Date Location Details Organisation Contact

Feb 1st to 3rd 2013 Pitlochry Youth Hostel

Annual General Meeting along with East Scotland Branch Field trip, Talk and Burns Supper are optional extras

West Scotland Branch

west.scotland@ougs.org

May 11th to 17th Assynt

Visit to the NW Highlands led by Dr Iain Allison There is now a waiting list for participants

Cliff Probert west.scotland@ougs.org

May 13th to18th Arran Presidential trip led by Dr Nick Rogers Chris Arkwright events@ougs.org

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ELECTRONIC ERRATIx Over half of our readers now receive their copy of ERRATIX via e-mail as a PDF file (300-500KB). If anyone else would like to do so, then please let me know (Adobe Reader can be downloaded free). Benefits are: • You’ll receive your copy 2-3 days ahead of postal delivery • It will be in glorious technicolour • You can store your copy on hard disk or print off if you wish – saving shelf space • Postal costs to the Society will be reduced.

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