West is Best ERRATIx OPEN UNIVERSITY GEOLOGICAL SOCIETY ~ WEST OF SCOTLAND BRANCH ~ NEWSLETTER ~ JUNE 2007 Branch Organiser: South Queensferry Field Trip Treasurer: Jacqueline Wiles Hammy Corrance 21 Wedderburn Road Sun 2nd Sept 36 Bensley Avenue Dunblane Dr Andrew McLeish Girdle Toll Stirling Ayrshire KA11 1AJ FK15 0FN Carboniferous rocks and fossils 01294 212801 01786 820127 Branch Web Site: [email protected] Dr McLeish has also offered to instruct us in local history, www.ougs-wb.org.uk famous people, ecology and Scottish football if there is time! Contact Jacqueline Wiles BRANCH ORGANISER’S BULLETIN Hello Everyone, I would like to welcome the new members who have just joined the society and hope they enjoy the newsletters and field trips. For those of you who have not renewed and have forgotten, a renewal form can be downloaded from www.ougs.org and sent to [email protected] . This will (I promise) be the last reminder. There has just been a very successful trip to NE Scotland with everyone having a great time. The next trip planned is in September with Dr Andrew McLeish at South Queensferry, and I hope to see some of you there. I am still trying to arrange another couple of trips for later this year, but am having a bit of trouble with dates so far, but E.Scotland have trips in June and August for anyone who wants to get out in the summer. I think I am slowly coming to grips with job as Branch Organiser, and attended my first committee meeting in April. This was very enjoyable, apart from having to get up at 4.30 in the morning, but everyone was very helpful and it was good to put faces to names. A lot of the time I seem to be passing e-mails round but please let me know if you do not want any with attachments as I know that if you do not have broadband (as I don’t) they can take ages to download. The Society is looking for someone to take over as Newsletter Editor later in the year when David Jones’ term ends, so anyone interested should get in touch with him. I hope that you all have a good summer and do not fall too far behind if you’re still studying. Jacqueline And from the Editor........... basement rocks – like Lewisian but where from?? – Hi everyone, Well the summer is moving on and the west (underlying all of Scotland), or the east some of us have been very busy!! The trip to the (Scandian event) or possibly Peru (again!!)?? After north east of Scotland went very well and we had a lunch we headed for Cromarty and Hugh Miller’s really great time. We began in Inverness Hostel on Cottage – fascinating. Saturday night was at the Friday evening where our leader gave us an Evanton, near Invergordon, and then we drove introduction to the geology of the week, and set off north to Golspie where we explored the Triassic on Saturday morning for the Black Isle and and Lower Jurassic conglomerates, sandstones and Cromarty, joined by two ‘local friends’. The mudstones of the shore section, wandering past the morning was spent on Eathie Shore, looking at imposing Dunrobin Castle and through masses of Moine psammites and some rather strange stunning bluebells in its grounds. We found a 1 possible reservoir rock for the Beatrice Oilfield, and an old quarry of Caithness flags and then made our the shale which might cap it, plus loads of fossils – way to the true north and Duncansby Head with its shells, burrows and coal. After lunch in the sun on spectacular stacks. We walked round the coast to the shore we visited the Orcadian Stone Company John o’ Groats, examining the sedimentary rocks, in Golspie to see a magnificent display of and some volcanics, with Orkney and the amazing wonderful rocks, minerals and fossils – truly one of cliffs of Hoy in the distance, and finally drove to the best – and a wee shop to spend money!! Lastly Thurso and our last hostel. we squeezed the bus through a tiny bridge under the railway to see Middle to Upper Jurassic sandstone south of Brora, and then headed for the hostel at Helmsdale. On Monday morning we examined the Portgower Boulder Beds with intervening sandstones, shales and fossils, in the Upper Jurassic. Halfway along, we met Nigel Trewin with a group of ‘professional business’ geologists! A highlight was the ‘Fallen Stack of Portgower’ – a huge chunk of MORS which fell off the submarine Helmsdale Fault scarp in Kimmeridgian times. We lunched at a windy Lothbeg Point and then examined the Kimmeridgian sandstones and shales of the shore section with its ammonites and other fossils, admiring and identifying the local birds. Then it was back to finish the Brora area (we ran On the shore at Sarclet (by Ian Henderson) out of time yesterday!), with another tiny bridge (!), before enjoying tea, ice cream etc in this lovely Thursday began at Dwarick Pier, in the rain, and the little town!! Tuesday, and we were off to try some Upper ORS of Dunnet Head. The beds were about gold panning at Kildonan on a rather a cloudy, 0.5m thick, with erosive bases, and traces of mud damp day. Again we were joined by ‘two other and rip-up clasts. The cross-bedding structures friends’, and had some success in finding tiny indicated a braided river system, flowing to the NE, pieces of the ‘yellow stuff’. After lunch beside the and there were good examples of soft sediment burn, we set off for the Helmsdale shore section – deformation suggesting earthquake activity when more boulder beds (this time Helmsdale) with large the rocks were only partly lithified. Southeast of blocks of ORS and also clasts of MORS flagstones the pier, wave-cut platforms enabled us to examine with a coarse bioclastic matrix, interbedded with the rock more closely. They were deposited as sandstones and shales. As we approached Navidale large alluvial plains at the margin of Lake Orcadie, Bay (in the sunshine), a dramatic seaward plunging with eroded sediment carried by braided rivers from anticlinal closure of the boulder beds was exposed the vast Caledonian Mountains. on the shore. In the distance we could clearly see Dun Glas, where the Helmsdale Fault crosses the shore and leaves the coast. On Wednesday we left Helmsdale and headed north, first to the Camster Cairns, ancient mysterious Neolithic burial mounds, set in a dip in the hills, and probably in use for more than 1000 years. Then to Whaligo Geo, a cove accessed by means of thousands of steps. We drove north to Sarclet, another spectacular cove, with intriguing rocks that were folded and fractured, with low angle dislocations, possibly a result of the nearby junction of the Helmsdale, Great Glen and Wick Faults. Soft-sediment deformation in the cross-bedded Upper ORS of Dunnet Head (by Avril Cormack) Here we lunched in the sunshine. We travelled to 2 We moved on to Brough Harbour where Middle granite sheet. On the beach were outcrops and (alternating sand and mud layers) and Upper ORS boulders of Port Mor marble, containing scapolite- meet, separated by a fracture zone due to movement diopside-orange spinel. Walking back across the on the Brough fault. After taking in the scenery at top of the cliff we found a string of retrogressed Dunnet Head, we drove to Dirlot and an pyroxenites with beautiful big dark crystals. unconformity between Moine schists and Middle ORS flagstones, with stromatolites coating the breccias between. Using the professional influence of one of our party, we obtained entry to a working quarry of Caithness flagstones for a very interesting visit, and lastly arrived at the disused Achanarras quarry, rooting around, with a permit, in the spoil heaps for some of its famous fish. In the evening we met for a group dinner in the Pentland Hotel, where Iain and everyone were thanked for such an enjoyable trip!! Descending into Port Mor (by Bob Alderman) Further west we came to Cnoc Mor, where strongly The party at Dunnet Head (by Bob Alderman) folded migmatitic gneisses display at least two phases of pre-Caledonian deformation, with folded It was Friday, our last day, and we drove west along axial surfaces producing hook-like structures (as the north coast to Portskerra harbour and the opposed to egg boxes or mushrooms!!). Then unconformity between Moine psammites and ORS across the Swordly Thrust to Glais Geo, near Farr (thought to be Middle). The sun, blue sky, wind Bay, where we traversed from the Bettyhill and rain kept coming and going all day!! Then to assemblage of quartzose gneisses to the hornblende Strathy Point, where a slice of very old lower schists/gneisses of the Clerkhill augen gneiss body, crustal gneisses and amphibolites were exposed. with huge ‘dent de cheval’ perthitic K-feldspars. We revelled in the garnets and searched for The augens were something to behold!!! Finally, staurolite before continuing towards Armadale, and near Clerkhill, in the rocks above the beach, we saw a granular quartz garnet rock on the Reismeave ‘some of the finest refolded folds in the British peninsula. Lunch in the sun on the hill and then off Isles’. One clearly showed three episodes of to the spectacular Port Mor gorge where folded and folding, three deformations, and was particularly deformed Moine biotite gneisses, amphibolites and amazing. granites to the west were separated from the tightly We returned to Thurso for the last night, and then folded, striped amphibolites of the Strathy complex dispersed on our separate ways on Saturday by a huge zone of sheared gneisses and morning, after a really fantastic week.