... and there is no original magnetization preserved. Flagstones of the Spital Group in the upper Caithness Flagstones have stable magnetizations carried by authigenic pseudo single-domain (PSD) magnetite apparently produced during early diagenesis. Throughout the Caithness Flagstones both normal and reversed components...

... . (1974) revised the stratigraphy of NE Caithness and subdivided the Upper Caithness Flagstone Group, above the Achanarras Fish Bed, into three subgroups. The lowest Latheron Subgroup was equivalent to the Spital Beds, the middle Ham-Scarfskerry Subgroup was approximately equivalent to the upper part...

... Published thickness ( Donovan et al . 1974 ) (m) Thicknesses from 11/25-2 ST1 (m) Unit Thickness Number of cycles Average cycle thickness Equivalent onshore outcrop average cycle thickness  Upper Caithness Flagstone Group ≥1500 Mey Subgroup 345 57 6.05 6.15 (Thurso, Andrews...

... is probably the result of low sedimentation rates in a low-relief region of the basin (Andrews & Trewin, 2010 ). A similar, low sedimentation rate, low-relief setting is postulated for stromatolites from the Upper Caithness Flagstone Group in the Thurso area on the north coast...

... succession is laterally equivalent to the Upper Caithness Flagstone Group of Caithness and consists of alternations of channel-dominated and sheet sandstone-dominated facies. When the thicknesses of the channel-dominated facies are plotted against their positions in the section ( Fig. 8 ), subordinate...

... (not shown), a splay of the Helmsdale fault, which parallels the coast a short distance inland. JOHN 0 GROATS SANDSTONE 4kmj UPPER CAITHNESS FLAGSTONE F LOWER CAITHNESS FLAGSTONE t- SARCLET SUB-GROUP 7777777777777772 MEY HAM- SCARFSKERRY LATHERON ROBBERY HEAD LYBSTER HILLHEAD CLYTH TYPE %Ro SECTIONS .OA...

... 4750m of cyclic Middle Old Red Sandstone lake sediments. This included more than 2300 m of the Lower Caithness Flagstone Group below the Achanarras Fish Bed, and at least 1450 m of the Upper Caithness Flagstone Group between the Achanarras Fish Bed and the mainly fluvial sediments of the John O Groats...

... on metamorphic rocks of the Moine supergroup at between −330 to −450 m OD ( Chapman & McEwen 1991). The rocks exposed in the cliffs and shore platform between Dounreay and Brims Ness to the NE have been assigned by Donovan (1980) and by Johnstone & Mykura (1989) to the Upper Caithness Flagstone Group...

... of the lacustrine sediments occurred during Eifelian – early Givetian time, represented by the Lower Stromness Flagstone Formation (Orkney), Upper Caithness Flagstone Group (Caithness) and middle Givetian Eday Flagstone Formation ( Fig. 2 ). These lacustrine sediments are characterized within the Orcadian Basin...

... th Lower Caithness Flagstone Group/Lower Stromness Flags from the Upper Caithness Flagstone Group/Upper Stromness-Rousay Flags. Definition of the top of the Devonian sequence at 1950 m is poorly constrained, given the absence of reliable palynological control above 2029 m. Authigenic illite fractions...

... ( Wilson 1935 ) separated the full sequence into Lower and Upper Stromness Flags, divided by the Achanarras–Sandwick horizon, followed by the overlying Rousay Flags and Eday Group. Miles and Westoll (1963) correlated the Spital beds of Caithness with the Upper Stromness Flagstone in Orkney, based...

... . Transactions of the Royal Society of Edinburgh , 69 , 167 – 201 , https://doi.org/10.1017/S0080456800015118 Hamilton , R.F.M. and Trewin , N.H. 1994 . Taphonomy of fish beds from the Upper Flagstone Group of the Middle Old Red Sandstone, Caithness . Scottish Journal of Geology , 30 , 175...

... collected from the Southhead Formation of Wick Flagstone Group (Lower Caithness Flagstone Group) exposed in Wick (Donovan et a1. 1974) and from the Thurso Flagstones of the Thurso Flagstone Group (Upper Caithness Flagstone Group) exposed in Sandside Bay, Reay (Crampton and Carruthers 1914, Mykura 1983) (see...

... stratigraphic sections. ( a ) Wester Clett; ( b ) Geodh' Ruadh; ( c ) Portskerra. The WCT shows features typical of subglacial till and has been regarded as the upper weathered part of the underlying EGT ( Gordon 1993a ). The usual maximum depth of oxidation in the Forse Till of SE Caithness is c...

.... Subaqueous shrinkage cracks from Caithness Flagstone Series (middle Devonian) of northeast Scotland J sedim Petrol 1972 42 309 17 Donovan R. N. Foster R. J. Westoll T. S. A stratigraphical revision of the Old Red Sandstone of northeastern Caithness Trans R Soc Edinb 1974 69 167...

...Benjamin H. Tindal; Anthony P. Shillito; Neil S. Davies Abstract Two newly discovered specimens of the fish locomotion trace Undichna ( U. britannica and Undichna isp.) are described from the Middle Devonian Achanarras Limestone Member (Caithness Flagstone Group, NE Scotland). Fish trace fossils...

... of the slab containing the chasmataspid. The strata in Achanarras Quarry [ND 150544]; see Trewin (1993 a , fig. 3 )) include the Achanarras Limestone Member at the top of the Lower Caithness Flagstone Group of the Middle Devonian fill of the Orcadian Basin (summary in Mykura 1991 ). The Achanarras...

... to date. Two main formations are known to contain vertebrate fossils at this level, the Lower Stromness Flagstone Formation in Orkney and the Lybster Flagstone Formation in Caithness; in western Caithness and Sutherland these are equivalent to the Bighouse and Sandside Bay formations. The Lower Stromness...

... Flagstone Formation (Givetian), the uppermost formation of the Upper Caithness Flagstone Subgroup, Eifelian-Givetian, Middle Devonian. Occurrence . Apart from the type locality, Fallodentus davidsoni also occurs at Lythmore, a drainage ditch to the east of Lythmore farm south of Thurso, Caithness...

... are in excess of 4 km thick and are divided into three stratigraphic groups based on lithology and fossil content (from oldest to youngest): the Lower Caithness Flagstone Group, the Upper Caithness Flagstone Group and the John O'Groats Sandstone Group ( Fig. 2c ; Andrews et al. 2016 ). With the exception...