Highland Geological Society | News | March 2025 Newsletter

March 2025 Newsletter

Added at 10:06 on 11 March 2025

The Highland Geological Society March 2025 Newsletter

Scottish Charity No. SC004427

Welcome to our March newsletter with details of our remaining lectures and information on the summer field trip programme.

HGS Committee

At the AGM there were some changes to the committee: Ann Reynolds stepped down after 2 years as chair, remaining on the committee; Stephen Young, our previous chair, has stepped down from the committee; and Andy Leggat has stepped down as webmaster, remaining on the committee. We would like to thank you all for giving your time and energy to do the many tasks needed and for all your contributions to the society.

HGS transition to a Scottish Charitable Incorporated Organisation (SCIO).

At our recent AGM we agreed that HGS should finalise a submission to become a SCIO and throughout the year members will be given updates on how the application is progressing.

HGS Website

Karen and Kathryn are continuing to gather ideas on how we can improve the HGS website and make it more interesting and useful for members. We are still exploring opportunities on how to advertise HGS with a view to increasing our membership.

List of Events

We now have two talks before the Summer Programme begins. David Jarman’s online talk on 30 April has been added, as explained. The talks begin at 7:30pm, and when in-person are held at the Inverness Youth Hostel, and an (optional) meal with the speaker is arranged beforehand. If you wish to join us for the meal on 26 March, please contact Anne Cockroft. Zoom details will be sent out shortly before the lecture.

Wednesday 26th March: Tom Sharpe, Geologist/Author. Mary Anning (In-person & Zoom)

Tom Sharpe is a geologist who has worked as a national museum curator, university lecturer, and expedition travel guide, mainly in the polar regions. He is a Fellow of the Geological Society and has been Chair of its History of Geology Group and Geological Curators’ Group, as well as a trustee of Lyme Regis Museum

Mary Anning described as ‘the greatest fossilist the world ever knew’. Drawing on recent research into her life and times, yet always aware of her character and personality, Tom Sharpe has taken a fresh and often surprising look at the achievements of a woman who is finally gaining the recognition she merits.

Wednesday 30th April: David Jarman, HGS. The Mull of Kintyre RSF (Rock Slope Failure) sequence (Zoom only)

Some of us will be visiting Kintyre on 3-10 May, on the excursion arranged by Ann Reynolds, see below. This talk will be of particular interest to those attending as we expect to see some of the features David mentions. It should also be of interest to those going to Cluanie and of general interest to all members and is open to all. David has spoken to us before about his research into Rock Slope Failures in Scotland. In 2013 and 2014 he visited the Mull of Kintyre, and this talk is based on his findings.

“A journey down the western coast of the Mull, discovering the extraordinary scale and extent of its failure, including some of the largest and most dramatic sites in Britain, second only to Skye for coastal locations. On the way, we can glimpse how people have made much use of this slipped and broken rim of the land - leaving scant remains...and poignant names for their precarious places”

Summer programme 2025

Saturday 3 to Saturday 10 May: Kintyre, HGS self-led

Wednesday 21 May: Cluanie, David Jarman

Tuesday 3 to Wednesday 4 June: Grampian Shear Zone, Dr Martin Smith

Day 1, Lochindorb and Loch an t’Sidheim. Day 2, Kincraig GCR

Thursday 14 August: Coire Glas hydro-scheme, Dr Martin Smith/Dr Romesh Palamakumbura (BGS) https://www.coireglas.com/project

Saturday 17 to Monday 19 August:: Ballantrae, Prof Alistair Robertson

Saturday 6 September: Nigg and Cromarty, Prof Peter Scott

Saturday 3 to Saturday 10 May: Kintyre and Gigha. Self-led trip arranged by Ann Reynolds

The intention is to spend the week exploring “the beautiful Isle of Gigha and the rarely visited geological sites on the Kintyre Peninsula. The geology will be a mixture of Dalradian, Carboniferous, and Quaternary”*. Ann and Peter have prepared a two-page summary with photos of some of the sites we expect to visit, available on request.

Self-catering accommodation has been booked in a farmhouse between Campbeltown and Machrihanish. We have 12 members booked to attend and all the places in the farmhouse are taken but if you still wish to come then you are welcome to join the field trip but you will have to find your own accommodation. This should be somewhere between Campbeltown and Machrihanish. There is a campsite at Machrihanish which also has lodges and static caravans – it is about 6 miles from the farmhouse.

*STOP PRESS: Devonian has now been added to the list.

Wednesday 21 May: Rock Slope Failures, Cluanie. David Jarman (HGS)

"This visit is to the densest cluster of RSFs (Rock Slope Failures) in the NW Highlands and exemplifies their strong association with breaches of the Main Watershed of Scotland. It highlights the general displacement east of that divide by Quaternary glaciation”.

We meet at the Cluanie Inn, Glen Shiel (Bakehouse café), and then walk up a stalker path climbing about 300m to Loch a' Mhaoil Dhisnich from where we should have views of a range of rock slope failures of different types. Optional open grassy ascent (no path) up a further 400m to explore a classic Rock Slope Deformation (GCR Site) on the flank of Druim Shionnaich. Return to Cluanie, continue by car to the Pass of Glen Shiel (1719 Battle site) to view foot of dramatic Sgurr na Ciste Duibhe rockslide (GCR Site).

Good footgear and reasonable walking fitness needed. Weather-dependent. The visit may be postponed or curtailed if the weather is poor, especially if the cloud base is low.

Tuesday 3 to Wednesday 4 June: Grampian Shear Zone, Dr Martin Smith

2-day trip, overnight at Grantown. Accommodation details tbc.

The Grampian Shear Zone is an enigmatic zone of distributed ductile shear located within the margins of a series of basement inliers in the Grampian Highlands of Scotland. It has been interpreted as a mid-crustal shear zone focussed along and obscuring, an unconformity at the base of the Dalradian Supergroup and a zone of thrusting repeating the cover basement contact. Early attempts to date the timing of shearing used Rb-Sr dating of muscovite porphyroblasts and yielded ages for the shearing at c. 740 Ma (Piasecki, 1980; Piasecki and van Breeman, 1983; Piasecki and Temperley, 1988). Later isotopic U-Pb age determinations of single grain zircon and monazite within syn-shear zone granitic pegmatites and the host rocks refined the ages to 840 ± 11 Ma in the host migmatitic and gneissose rocks and 806 Ma from the syn-tectonic granitic pegmatites confirming pre-Caledonian (Knoydartian) tectonothermal events (Noble et al., 1996; Highton et al. 1999).

The aim is to investigate two key GCR sites where the Grampian Shear Zone and surrounding rocks can be observed.

Day 1: Lochindorb and Loch an t’Sidhein GCR – basement gneisses, shear zone with metagabbros, granitic pegmatite, interleaving of gneissose and non-gneissose lithologies. If time permits we will also look at Grampian Group lithologies with good sedimentary structures.

Day 2: Kincraig GCR – traverse from basement gneisses up through the shear zone and an amphibolite unit into basal Grampian Group represented by a condensed sequence of semipelite, pelite, calc-silicate rock and metalimestones. Above are thinly banded ‘rhythmites’ passing up into graded bedded psammites of the Grampian Group.

Thursday 14 August: Visit to Coire Glas pumped hydro scheme (in development), Dr Romesh Palamakumbura (BGS)

“Coire Glas is the first large scale pumped hydro storage scheme to be developed in the UK for more than 40 years. It is located on the shores of Loch Lochy in the Scottish Highlands, between Fort William and Inverness and has a potential capacity of up to 1300MW with energy storage of around 30GWh. It will double Great Britain’s existing electricity storage capacity, providing homegrown renewable energy when the demand is high or other variable generation is low. The Coire Glas project is 100% owned by SSE Renewables”

See https://www.sserenewables.com/hydro/coire-glas

https://www.coireglas.com/project

Devonian sediments, and fracture systems associated with the Great Glen Fault.

Saturday 17 to Monday 19 August: Ballantrae, Prof Alastair Robertson (University of Edinburgh)

“Observation, discussion and interpretation of rock types and settings related to the genesis and emplacement of the Ordovician Ballantrae Ophiolitic Complex and related units, Ayrshire”

There are 19 participants and our leader – there may be room for a few more.

Three full days – arrive Saturday afternoon, geology on Sunday, Monday and finish Tuesday afternoon and drive home on Tuesday late afternoon/evening. If anyone else is interested in joining us please note that participants have independently booked to stay in Girvan - many at the Westcliff Hotel (Tel: 01465-712128). The owner is very helpful and if she still has rooms then mention that you are with the HGS. The cost is £80 for a double/twin bed with no breakfast or £90 with breakfast for 2 for an ensuite room. Those of the party staying in this hotel will be making their own arrangements for dinner, as the hotel no longer does evening meals. You will need to provide your own lunch. Some of the exposures require care as the rocks may be slippery, although the dates have been chosen for low tide.

It is recommended that you read chapter 6 of the 5th ed of the Geology of Scotland. Other geology books will have summaries of these rocks but the one mentioned is the most up to date.

Saturday 6 September: Prof Peter Scott: Nigg and Cromarty.

Due to the time of low tide this will be an afternoon and early evening excursion. We plan to arrange a meal together in Cromarty at the conclusion. If you have a Highland Bus Pass, then bring it – it will cover the cost of the ferry crossings.

We expect to start this field trip at about 14.00, meeting at Nigg ferry pier in Cromarty after everyone has had their lunch. The object of the trip is to look at the Old Red Sandstone, first on the north shore as far as North Sutor and then on the south shore as far as South Sutor. We shall also examine the unconformity with the Moine and the fish beds on the south shore. Expected finish time about 19.00.

Items of interest, geological websites

SGT Geosite and SGT GeoGuide.

The SGT Geosite project continues apace with many Scottish SSSIs and GCR sites now covered with a photographic record. https://geosites.scottishgeologytrust.org/

The accompanying SGT GeoGuide website now has scanned versions of an incredible 173 publications including all GCR volumes, a huge resource: https://geoguide.scottishgeologytrust.org/

Orkney Science Festival YouTube channel

This channel features videos produced for the Orkney Science festival and features geology, geomorphology, archaeology and local history and is recommended.

https://www.youtube.com/watch?v=CaGCmTAfF98

Hugh Miller Cottage Museum

https://www.nts.org.uk/visit/places/hugh-millers-birthplace/

Friends of Hugh Miller

A link to the Friends of High Miller website https://www.thefriendsofhughmiller.org.uk/

The Scottish Geology Trust

http://www.scottishgeologytrust.org/

Other Scottish geological societies:

Aberdeen Geological Society

http://www.aberdeengeolsoc.org.uk/

Edinburgh Geological Society

https://www.edinburghgeolsoc.org/