Vol. 62.] GLACIAL PEEIOO IN AEEEDEEXSHIBE, ETC. 19 



this was a deep mass — 20 feet thick or more — composed of 

 darkish mottled brown clay, varying much in colour, as if a red 

 and a blue had been jumbled together. It was quite unstratified, 

 and contained more stones than the Red Clay beneath. These 

 stones are of a great variety of kinds, and among them are some 

 large ice-worn boulders, from 2 to 4 feet long. Above this came 

 from 3 to 4 feet of coarse pebbly clay, of a more ferruginous 

 tint, with a foot or so of arable soil at the surface. The total 

 height of the bank is about 65 feet above the sea. The relative 

 thickness of the beds varies in different places, but the section is 

 now quite obscured by slips. In some places here the Red Clay 

 is curiously streaked with clay of a dark bluish colour, derived 

 apparently from a different source. In one spot, near the base 

 of the section, I found a boulder of granite 2 feet in diameter, 

 sticking in the fine sand and reaching partly up into the laminated 

 clay above it. This stone was encased in a skin of bluish-grey 

 gritty mud, 1 or 2 inches thick, quite different from the clay 

 surrounding it, as if the stone had been covered with this mud 

 when it dropped out of the ice, and fell down into the clay at the 

 bottom of the water. 



In the excavations for the convict-prison, which adjoins Inver- 

 nettie on the south side, an irregular undulating band of blue clay 

 was found in the midst of the red, accompanied occasionally by a 

 bed of gravel, which contained a few broken shells. Many blocks of 

 red sandstone were met with in the cuttings for the prison ; likewise 

 a bit of hard Chalk, with a cylindrical fossil in it about the size and 

 thickness of a cigarette (? Belemnitella), and stones of many different 

 kinds. Among the broken shells, I observed Gyprina islandica, Pecten 

 islanclicus, Astarte arctica, Panojxea, Mytilus, Oardium, Fiisus, and 

 Balanus. 1 



I have noticed a similar bed of blue clay among the red near 

 Cruden Bay. It is generally very undulating, of irregular thickness, 

 and contains ice-scratched boulders. To the north of Peterhead, 

 in the parish of St. Fergus, dark-blue clays are more developed, 

 and are found embedded in the red, which shows that they belong 

 to approximately the same period. North of St. Fergus the Red 

 Clay disappears, and is replaced by clay of a dark indigo colour, 

 sometimes nearly black. This dark clay extends along the coast 

 westward, past Banff, on to Portsoy and Cullen, and indicates a 

 transport from north-west or west. 



Since writing my former paper on the Red Clay 1 have 

 found a few more instances of glacial markings on the rocks 

 along the coast of Cruden, running in a general direction 

 from south to north, or parallel to the coast ; but t^ey were 

 exceedingly slight and of no great extent. Those at Murdoch 

 Head, pointing towards the Buchan-Xess Lighthouse, are still the 

 best that I have been able to discover, and are unequivocal. The 



1 Further details regarding the clay -beds near Peterhead will be found in 

 Quart. Journ. Geol. Soc. vol. xiv (1858) p. 518. 



