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Spey Bay
The Spey Bay area around the mouth of the River Spey on the Moray coast is
Britain's best example of a shingle strandplain. The whole area has allowed
for the study of the interaction between active and relict coastal and fluvial
processes - unlike any other river estuary in Britain today. Active and relict
shingle ridges are juxtaposed with other coastal and fluvial landforms that
represent the area's evolution since the end of the last ice age approximately
10,000 years ago.
At the end of the last ice age, a rapid rise in sea level flooded the mouth
of the Spey, forming a wide estuarine embayment. Large quantities of shingle
were washed onshore as a result of the rising sea levels. This, in addition
to the post-glacial shingle being washed downstream, caused the embayment to
become infilled (i.e. prograding). As sea levels fell again, an extensive shingle
ridge system developed. These relict ridges remain very well preserved and
their trend indicates that the orientation of the coastline has switched over
time from E-W, to WNW-ESE. The currently active ridges stretch for over 8km
along the coast.
Landforms near to the mouth of the River Spey indicate a complex geomorphological
history that combines both fluvial and coastal processes. These landforms include
raised delta, marine deposits, river terraces, palaeochannels and glacio-fluvial
deposits. Active processes include the formation of a shingle spit, a large
offshore delta and small areas of saltmarsh. Although the evolution has been
dominantly progradational, evidence of active regression has been identified
in most parts along the complex in recent years.
Further reading:
Gregory, K.J. 1997. Fluvial Geomorphology of Great Britain, Geological Conservation
Review Series No. 13, Joint Nature Conservation Committee, Peterborough.
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