18G0.] JAMIESON CKAG, ABERDEENSHIRE. 371 



height of from 30 to 40 l'cet above the present tide-mark. 

 Patches of forest-ground were submerged along the coast. The 

 clays and beds of silt, forming the " carses " of the Forth, Tay, 

 and other rivers, -were accumulated, as well as the post-ter- 

 tiary beds described by Mr. Smith of Jordanhill (Trans. Geol. 

 Soc. vol. vi. p. 153), the shells of which agree with those of our 

 present seas. 

 5th. An elevation at length took place, by which the land attained 

 its present level. As Mr. Smith has shown (see Werner. Soc. 

 Memoirs, viii. p. 57), this probably occurred before the Roman 

 invasion ; but that Man had previously got into the country 

 appears from the fact of the elevated beds of silt near Glasgow 

 containing overturned and swamped canoes with stone imple- 

 ments (sec Erit. Assoc. Report, 1855, Sect., p. 80). 



On the Occurrence of Crag Strata beneath the Roulder-clay in 

 Aberdeenshire. Uy T. F. Jamieson, Esq. 



I [Communicated by Sir Roderick I. Murchison, V.P.G.S., &c.] 



[Read June 13, 18G0, but, by permission of the Council, printed here in asso- 

 ciation with the foregoing paper, which has reference to the same district.] 



In the parishes of Slains and Cruden (see Map, p. 348) we have beds 

 apparently of the same age as the English Crag formation. They 

 consist of stratified sand and gravel underneath the boulder- clay, 

 and reposing upon the old rocks of the district. I need not enter 

 into any description of the locality in which these deposits occur, nor 

 of their general character, as these will be found detailed in a paper 

 on the Pleistocene of Aberdeenshire, which the Geological Society 

 did me the honour of printing in the 14th volume of their Journal 

 (see pp. 522-525). 



I had even at that time some suspicion of their Crag character, 

 from their position below the boulder-clay, and, further, from the 

 total absence of any glacial stria; or polish upon the pebhles : but I 

 have since then made a close search amongsl the comminuted shell- 

 fragments that are everywhere sparingly scattered through the mass; 

 and it ie from the character <>f these, combined with the geological 

 position of the strata, that I infer the age to be probably that of 

 either the Red or the fiiammaliferous Crag of England. 



I have upwards of a score of hinge-fragments which I tan Bafely 

 refer to tlic Oyprina rustica or Venus rustiea ofSowerby'fl ' Mineral 

 Conchology' — a shell which is unknown in the drift-beds, and which, 



so far as I am aware, lias been found only in the Crag; likewise a 

 few fragments of the Fusus contrariw, another Crag form. 



The prevailing species of Pecten, so bras I can judge from the small 

 pieces 1 have collected, i-, the Crag variety of /'. operations, viz. /'. 

 opereularis, var. Audovxni. Borne of the species of AstarU appear 

 also to belong to A. Omalii) and the only specimen of Purpura i^ 



a Crag \ariet\ of /'. lapilllU {int. I'. Injiillns, var. inrinsstidi of . s . 



