Glenelg – Attadale Inlier residential trip

Leader: Professor Simon Cuthbert 

This four-day excursion visits part of the northwest Highlands opposite the Isle of Skye that is well known for its dramatic scenery and human stories, encompassing the dramatic fjord of Loch Duich and Lochalsh, Eilean Donan Castle, the hidden gem of Glenelg and Sandaig Bay. Exposed in these hills and shores, emerging from under the Wester Ross Supergroup (the “Moines”), is an enigmatic complex of ancient gneisses – the Glenelg-Attadale Inlier (GAI), the largest of the so-called “Lewisianoid” basement Inliers of the Northern Highlands Terrane. The rocks resemble the Lewisian Complex further north, but enclose a beautiful garnet-pyroxene rock-type – eclogite – that formed at extreme pressure when this continental crust was subducted during continental collisions. This is the only example in the British Isles of well-preserved eclogite and is unusually old for such rocks – early to mid-Proterozoic – and were formed long before they were caught up in the Caledonian orogeny and thrust westwards along the Moine Thrust system. This area is where some of the great figures of Scottish geology have worked and we can admire their insights and originality.

Thurs: We will meet in Glenelg in the afternoon of the first day, with the option of exploring the hillside above the village and / or visiting the fascinating Brochs at Gleann Beag. 

Friday: On the second day we will climb about 300m up into the hills north of Glenelg to see gneisses, marbles and c. 1200 myr old eclogites with (hopefully!) spectacular views to Skye and the peaks north and south. 

Sat: On day 3 we drive over the high Bealach Ratagain with superb views of the Kintail mountains and a chance to see the late Caledonian granites of the Ratagan pluton, then swing northwest along the south shore of Loch Duich see high-pressure gneisses that show, perhaps surprisingly, how continental crust may be subducted. We will explore structures and timing in eclogites and climb the hillside to see a very unusual iron-rich metamorphic rock known as “eulysite” – one for the mineral fanatics! Then we will visit the spectacularly located Eileen Donan Castle and nearby garnet granulites of the GAI, then take in another great view from Carr Brae high above the loch. 

Sun: On day 4 we will walk down to beautiful Sandaig Bay, Gavin Maxwell’s “Ring of Bright Water” to see much older, c. 1700 myr. eclogite bodies similar in age to the Rhinns complex on Islay and the Laxfordian of the main Lewisian outcrop. We will also see the contact of the “Lewisianoid” gneisses with the Wester Ross Supergroup schists and a mylonite shear zone related to the Caledonian Moine Thrust. 

Monday: On the final day, before returning home, there is the option of stopping in the dramatic glacial trough of Glen Shiel to see the Sgurr Beag Slide marking the top of the Moine Nappe and Glenfinnan Group migmatitic gneiss in the Loch Ness Supergroup. 

The region we will visit has seen some interesting new interpretations recently, but overall tells the story of three episodes of supercontinent assembly including the enormous Grenville-orogeny, possibly the greatest mountain-building in Earth’s history. The excursion will explore the evidence, but should reward you regardless of whether you are a metamorphic fanatic or just love beautiful rocks and scenery! If you are a student studying geosciences you might wish to join to gain some extra experience of high-grade metamorphic rocks and structures.

*Reaching some of the sites will require good mobility, stamina and physical fitness.

Travel to the field area and during the trip will be in participants’ own vehicles; please share if you can.

Hotel accommodation has been pre-booked at the Glenelg Inn, and Seaview Cottage both in Glenelg village.

Costs:

4 nights bed and breakfast at the ‘Glenelg Inn’

3 sharing a room £274.00 pp

2 sharing a room £320.00 pp

Double room £520.00 single occupancy or £640.00 per couple.

OR

4 nights Self Catering at ‘Seaview’ cottage £206.00 per room. (Only 4 available)

**Each option is Plus £55 pp towards leaders costs. (Only returned if trip is cancelled at least 4 weeks before departure)

*Lunches and evening meals are not provided, packed lunch can be supplied at around £15 each and evening food can be purchased in the hotel.  Members will be responsible for paying their own meals and drinks directly to the hotel. These do need to be booked in advance.

A useful introduction to the area can be found in two articles by Craig Storey: Scottish Journal of Geology 44, 1–16 and 17–34 (2008).

* PLEASE PAY ONLY THE DEPOSIT AMOUNT AT THIS TIME TO CONFIRM YOUR SPACE AND WE WILL COLLECT ACCOMMODATION COSTS AFTER PLACES HAVE BEEN CONFIRMED **DEPOSIT DUE BY 31st MAY 2025**