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J.S.Smith
accumulated, is governed by the varying lithologies of the solid geology along the land
margin. Three broad sub-divisions can be identified where differences of lithology and
orientation have created distinctive coastal scenery.
(a)
(b)
(c)
The Highland schists of the Banffshire coast
The granites, gneisses and schists of the east coast of Aberdeenshire, to
the north of the Highland Boundary Fault
The younger sedimentaries downfaulted south of the Highland Boundary
Fault, the outliers at Pennan, together with the downwarped sedimentary
formations of the Moray Firth basin, west of Spey Bay
The Banffshire coast consists of a generally high rocky coastline with small
bays orientated in sympathy with the rapidly changing geological succession of the
Highland schists. Beach units are small and generally separated from each other by
rock cliff headlands and deep water. The bayhead orientation is continued inland by
strike-stream valleys, often markedly overfit in relation to current fluvial activities, and
the fluvial input, with the exception of the Deveron, is generally small. The coastal
scenery is bedrock-dominated and rapidly changing in character along the geological
succession.
On the east Aberdeenshire coast, the role of the underlying bedrock, although
by no means uniform, is subordinate to Pleistocene and post-Pleistocene events. With
the notable exception of the granite coastline north of Collieston (especially at Buchan
Ness), and the intricate cliff coast between Girdleness and Stonehaven, the character of
the coast is of extensive arcuate dune-backed embayments, hinged on low bedrock
outcrops and lag glacial deposits. Fluvial inputs while locally significant, are not
impressive in their supply of beach material.
West of the Spey and south of Stonehaven, the younger sedimentary rocks
form substantial lengths of high cliff coast, with variation in character according to
lithology. Particularly impressive are the Devonian conglomerate sea cliffs at Fowl's
Heugh, just south of Dunnottar. On the north coast Permian sandstones form a very
distinctive series of low sea cliffs between Covesea and Burghead, but west of this
point, and between Lossiemouth and Portgordon, the coastline is dominated by major
strandplains of late- and post-glacial age, again as in the case of the east
Aberdeenshire coast, supported by bedrock outcrops.
In relation to the soft and therefore potentially dynamic coastal elements, the
solid geology forms a varied platform on which beaches and landward blown sand
deposits have accumulated. But over more than 80% of the sandy beaches, bedrock
geology forms a minor element in their evolutionary history and present
characteristics. Exceptions occur on the Banffshire, Kincardineshire and Moray coasts,
where the beach units are set in small bayhead situations resting on rock platforms.
Here the beach arc and its landward landform characteristics are closely governed by
the geological framework within which it is lodged.
J.S.Smith
accumulated, is governed by the varying lithologies of the solid geology along the land
margin. Three broad sub-divisions can be identified where differences of lithology and
orientation have created distinctive coastal scenery.
(a)
(b)
(c)
The Highland schists of the Banffshire coast
The granites, gneisses and schists of the east coast of Aberdeenshire, to
the north of the Highland Boundary Fault
The younger sedimentaries downfaulted south of the Highland Boundary
Fault, the outliers at Pennan, together with the downwarped sedimentary
formations of the Moray Firth basin, west of Spey Bay
The Banffshire coast consists of a generally high rocky coastline with small
bays orientated in sympathy with the rapidly changing geological succession of the
Highland schists. Beach units are small and generally separated from each other by
rock cliff headlands and deep water. The bayhead orientation is continued inland by
strike-stream valleys, often markedly overfit in relation to current fluvial activities, and
the fluvial input, with the exception of the Deveron, is generally small. The coastal
scenery is bedrock-dominated and rapidly changing in character along the geological
succession.
On the east Aberdeenshire coast, the role of the underlying bedrock, although
by no means uniform, is subordinate to Pleistocene and post-Pleistocene events. With
the notable exception of the granite coastline north of Collieston (especially at Buchan
Ness), and the intricate cliff coast between Girdleness and Stonehaven, the character of
the coast is of extensive arcuate dune-backed embayments, hinged on low bedrock
outcrops and lag glacial deposits. Fluvial inputs while locally significant, are not
impressive in their supply of beach material.
West of the Spey and south of Stonehaven, the younger sedimentary rocks
form substantial lengths of high cliff coast, with variation in character according to
lithology. Particularly impressive are the Devonian conglomerate sea cliffs at Fowl's
Heugh, just south of Dunnottar. On the north coast Permian sandstones form a very
distinctive series of low sea cliffs between Covesea and Burghead, but west of this
point, and between Lossiemouth and Portgordon, the coastline is dominated by major
strandplains of late- and post-glacial age, again as in the case of the east
Aberdeenshire coast, supported by bedrock outcrops.
In relation to the soft and therefore potentially dynamic coastal elements, the
solid geology forms a varied platform on which beaches and landward blown sand
deposits have accumulated. But over more than 80% of the sandy beaches, bedrock
geology forms a minor element in their evolutionary history and present
characteristics. Exceptions occur on the Banffshire, Kincardineshire and Moray coasts,
where the beach units are set in small bayhead situations resting on rock platforms.
Here the beach arc and its landward landform characteristics are closely governed by
the geological framework within which it is lodged.