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You are here > Home > Out & About > Classic
Sites:
Isle of Skye - Trotternish 
(Other classic sites on Skye include The
Cuillin Hills and Jurassic dinosaur
footprints at An Corran)
After the Cuillin Hills, Trotternish
is perhaps the next most visited part of Skye. Stunning scenery at the
Quirang and the Storr, post-glacial large-scale landslides, ensure that
the area is well photographed. The landslide at the Quirang is the largest
mass movement slide in Britain, extending over 2km in width. Geologically,
the west and northern parts of Trotternish consist of Jurassic sedimentary
rocks and Palaeogene
lavas intruded by later Tertiary dolerite sills. Although Jurassic rocks
are relatively rare elsewhere in Scotland, Skye offers the most complete
sequence of Jurassic
rocks in the country, with Trotternish being one of the main exposures.
The Quirang - foundering of a thick sequence
of Palaeogene lavas over the underlying Jurassic age sedimentary rocks,
has produced a landslide terrain. © Colin MacFadyen /Scottish Natural
Heritage.
The rocks at Trotternish consist of Jurassic sedimentary sequences overlain
by thick Palaeogenelava flows. Dolerite sills and dykes intrude the Jurassic
rocks. All the rocks dip gently to the west, creating slopes rising gently
across Trotternish peninsula from west to east, with steep scarp slopes
on its eastern margin. N-S trending faults are also developed along the
peninsula. The slides formed due to the overlying weight of the lava flows
(a total of 24 flows, approximately 300m thick), weighing down on the
weaker Jurassic sedimentary rocks. Under the pressure, the Jurassic rocks
sheared along the N-S faults and huge blocks slid seawards along a rotational
glide plane.
Bearreraig Bay, Skye - interpretive panels located
above the cliffs at Bearreraig Bay, interpret important Jurassic rock
sequence and associated fossils. © Colin MacFadyen/Scottish Natural
Heritage.
At the Quirang, five successive movements have been identified, extending
over 2km from the scarp slope to the coast. Although features such as the Storr
and the Quirang are currently stable, other areas remain active.
The sedimentary sequences at Trotternish comprise Middle and Upper Jurassic
clays, shales and sandstones. Bearreraig Bay offers an excellent opportunity
to examine exposures of Middle Jurassic sedimentary rock sequences.
Further reading:
Ballantyne, C.K. (2007) Trotternish Escarpment, Isle of Skye. In Mass
Movements in Great Britain (R.G. Cooper), Geological Conservation
Review Series, No. 33, Joint Nature Conservation Committee, Peterborough,
pp 196-204.
Bell, B.R. & Harris, J.W. 1986. An Excursion Guide to the Geology
of the Isle of Skye. Geological Society of Glasgow.
Stephenson, D. & Merritt, J. 2002. Skye - A
Landscape Fashioned by Geology. Produced by: Scottish Natural
Heritage & British Geological Survey.
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