396 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 1, 



Cephalaspis-zoRQ of ShropsMre and Herefordshire in England, and 

 of Eorfar and Perth in Scotland. 



I examined the partial uprise of these lower beds through the 

 Caithness flags at Sarclet, four nules south of Wick, — a point to 

 which my attention was called by Mr. Peach. When seen from the 

 sea, as represented in fig. 10, it is manifest that the lower rocks have 



Fig. 10. — Section of the Lower and Middle Members of the Old Bed 

 Sandstone at Sarclet, near Wick. 



S. Sarclet. N. 



Caithness Old Red conglomerate Caithness flags, 



flags. and sandstone. 



been protruded by great force, which has subjected the whole of 

 the flanking series of flagstones to extensive transverse breaks and 

 fractures, which, on examining the shore, are found to exist with 

 partial reversals of dip. The little thriving fishing-station of Sarclet 

 is one of those numerous iadentations of the coast of Caithness which 

 the stormy eastern ocean has helped to open out, but which, like 

 many of the other coast- clefts which I have seen, is mainly due to an 

 original powerful dislocation, resulting in transverse gullies which the 

 sea has simply widened or deepened. Here the breccia or conglo- 

 merate, as at the Ord of Caithness, is made up chiefly of granite and 

 quartz-rock, both grey and white : the imbedded fragments, from the 

 size of a bullet to that of a man's head, are sometimes angular, but 

 often rounded as if they had undergone shore- action. Piled up in 

 massive beds of from 15 to 20 feet each, which alternate with deep- 

 red shaly layers, this conglomerate, where I examined it (for it folds 

 over in a very broken arch), dips to the north, and passes under 

 strong-bedded, hard, fine-grained micaceous grit, freckled with marks 

 of iron- ore, which in its turn is covered with thinner beds distin- 

 guished by their rippled surface. This upcast broken mass is seen to 

 be covered by the flagstones, which, as we ascend in the series, 

 whether by going towards Wick on the north or to the Yarrow Hills 

 and to Latheron on the west and south, become fossiliferous and 

 constitute the bituminous flagstone group. It is worthy of remark, 

 that even some of the lower red grits and sandstones eifervesce with 

 acids, like many portions of the overlying Caithness flags. 



Another spot where the older conglomerate and sandstone have 

 been protruded through the broken undulations of the Caithness 

 flags, is at Dirlet Castle, in the interior of the county, and about 

 twelve miles W.S.W. of Thurso, to which Mr. Peach and myself 

 were directed by that zealous and able explorer of rocks and fossils, 

 as weU as of Kving plants, Mr. Eobert Dick (see fig. 11). There a boss 

 of flag-like gneiss (probably the newer gneiss, but largely affected by 

 intrusion and pierced by granite), which is covered by the ruins of the 

 old castle, stands out of the middle of the Thurso Water. This cry- 

 stalline rock, dipping sharply to the E.S.E.,"is surmounted, as shown 

 in this diagram, by a coarse conglomerate, almost a breccia, which 



