(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

Devonian	Late	Famennian	354 to 364
		Frasnian	364 to 370
	Middle	Givetian	370 to 380
		Eifelian	380 to 391
	Early	Emsian	391 to 400
		Praghian	400 to 412
		Lochkovian	412 to 417

Givetian 370 - 380 MYA
FORMATIONS AND DEPOSITS			LOCATIONS
M I D D L E R E D S A N D S T O N E	Carne Formation		Pendower Beach
	Millbuie Sandstone Group		Eathie Balintore Cromarty Tarbat Ness
	Strath Rory Group
	John O'Groats Sandstone Group		John o' Groats
	Upper Caithness Flagstone Group	Mey Subgroup	Thurso
		Ham-Skarfskerry Subgroup	Thurso
		Latheron Subgroup	Thurso
		Spital Beds	Spittal Thurso
	Achanarras & Niandt Limestone Member		Achanarras
	Lower Caithness Flagstone Group	Robbery Head Subgroup
		Lybster Subgroup

1:250 000 Geological Map of Achanarras Geological Maps are sold either Flat or Folded for Solid, or Seabed geology. Special editions may be available for certain locations. For a complete list click the link below. Click here to BUY ONLINE from our Store

1: 50 000 Geological Map of Achanarras Geological Maps are sold either Flat or Folded for Solid, Drift or combined geology. Special editions may be available for certain locations. For a complete list of 1: 50 000 maps, click the link below. Click here to BUY ONLINE from our Store