64 Robert Campbell — South- Eastern Kincardineshire. 



Upper Cambrian (?). 



Between Craigeven Bay and Garron Point occurs a series of crushed 

 green igneous rocks with thin intercalated black shales, jaspers, and 

 cherts, which are shown on the Geological Survey Maps as of 

 Arenig(?) age. In August, 1909, on the occasion of a visit to 

 Craigeven Bay in company with Dr. B. jST. Peach and Mr. W. T. 

 Gordon, we spent some time in searching for fossils in the above- 

 mentioned sediments, and in the black shales we succeeded in finding 

 organic remains, including a linguloid shell and a bivalve phyllocarid 

 crustacean. The assistance of Mr. D. Tait, of H.M. Geological Survey, 

 was obtained in making a detailed search in the fossiliferous beds. 

 He collected a remarkable suite of fossils which have thrown important 

 light on the age of these rocks. Dr. Peach, in whose hands the fossils 

 were placed for determination, has very kindly supplied the following 

 note : — 



"The collection includes several specimens of hingeless brachiopods 

 belonging to the genera Lingulelia, Ololella, Acrotreta, Linnarssonia, 

 and Siphonotreta ; a few specimens of a bivalve phyllocarid allied to 

 Caryocaris and Linguloearis ; cases of a tubicolar worm, the structure 

 of the tubes being like that of the modern Bitrupa. 



" Without further study it may be premature to express a definite 

 opinion about the horizon of these fossils. The genera represented 

 are most commonly found in the lowest division of the Lower Silurian 

 (Ordovician) system and the Upper Cambrian. The absence of grapto- 

 lites, however, suggests that they may belong to the latter rather than 

 to the Lower Silurian." 



These rocks extend as a narrow belt from St. Mary's Chapel to 

 Garron Point (see Sketch-map). Whatever may be the ultimate 

 decision as to their stratigraphical horizon, it will readily be admitted 

 that the fossils must determine also the age of the similar groups of 

 green crushed igneous rocks and associated sediments which occur at 

 intervals along the Highland border. 



The Highland Fault. 

 The Highland fault has hitherto been represented as a normal fault 

 forming the boundary between the Old Bed Sandstone formation and the 

 older rocks to the north-west. A visit to the coast section at Craigeven 

 Bay, in company with Dr. B. N. Peach, showed us that, along the 

 south shore of the bay, what has hitherto been regarded as the Lower 

 Old Bed Sandstone formation rests unconf ormably on Upper Cambrian (?) 

 strata. This boundary-line has always been looked upon as marking 

 the line of the Highland fault, and, indeed, masked as the unconformity 

 is by minor faulting and by the red staining of the underlying rocks, 

 it is not perhaps surprising that the basement breccia has been mistaken 

 for a fault breccia. The northern boundary of the Cambrian (?) is an 

 overthrust fault, and this line of faulting is probably the continuation 

 of the great Highland fault, which elsewhere in this district forms the 

 northern limit of the Old Bed Sandstone. In the only inland section 

 in Kincardineshire in which the actual line of fault was seen — in 

 a small stream near Elfhill, about 6 miles west of Stonehaven — the 

 fault is undoubtedly an overthrust. 



