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(The Devonian Rocks of Achanarras Quarry) - 2003
The Caithness Flagstones of the Achanarras
Quarry from the Devonian period are of the Achanarras
Beds. It is difficult to determine the exact zones
since the quarry during the end of its production
period started to infill with spoil. The fish beds
are laminae, originated as non-glacial varves. The
upper fish bed is between two beds of thinly-interlaminated
siltstone and shale with mound structures where as
the lower fish beds are between thicker laminae of
shale and coarse siltstone and shale with shrinkage
cracks. The fish bed can be easily seen since the
upper fish bed is between two zones of a black bed
with mound structures and the lower fish bed sits
under a third black band.
(Caithless Flags, Achanarras Quarry) - 2003
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