1858.] JAMIESON PLEISTOCENE, ABERDEENSHIRE. 517 



layers of fine brick-red clay. The appearance of these sandy strata, 

 deep down in this bank, very closely resembles the lower part of the 

 cliff at Collieston ; and in like manner I found them to contain mi- 

 nute fragments of shells. A shell, said to have been obtained in 

 these banks, is in my possession, which I received from Mr. Dawson 

 of Cruden. It appears to be the Mangelia turricola of Forbes and 

 Hanley, and is somewhat water-worn, although almost entire. The 

 only stone of any kind which I found in these sandy layers was a 

 small pebble of flint. The strata here are horizontal, not undulated, 

 but often finely rippled. 



Higher up, the sandy strata seem to be of a more reddish hue, 

 containing seams of red clay ,- and some coarser stuff, with boulders, 

 appears to occur occasionally, as if it had slipped down in some 

 places. The upper part of the bank is not exposed by any good 

 section, but seems still sandy ; while higher up still, where the 

 ground slopes back, there is some coarse gravel or stony stuff ex- 

 posed at the side of the adjacent fields. 



These Pleistocene deposits, although still of great depth in this 

 locality, have no doubt been worn down and washed away to some 

 extent during the course of events which intervened betwixt the 

 period of their deposition and the last movement of elevation. This 

 denuding agency, in cutting down the stratified beds, must have 

 thrown their materials, together with other debris, into positions 

 which are now difficult to be explained. It will be safest, therefore, 

 to rest any theories upon good, clear, extensive sections, where this 

 disturbing element can work no mistake. 



To the north of Cruden Bay the coast is composed of red granite 

 all the way to Peterhead, forming cliffs from 70 to 150 feet high, 

 and upwards. The top of these rocks is more or less bare, and 

 destitute of any considerable covering of loose matter. In some 

 places a depth of 3 to 4 feet of clay and stony rubbish occurs ; and 

 it is worthy of note that the stony debris is not made up of granite, 

 but of the detritus of slaty gneiss, with varieties of porphyry and 

 quartz : sometimes a few bits of red sandstone may be found. Some 

 slight difference may be occasionally remarked in this superficial 

 mass, the upper part being less stony, and of a red colour, more of 

 the nature of red clay, while the lower portion next the granite is 

 little else than a mass of small stony debris, the fragments mostly 

 angular or little worn, although there are also many rounded peb- 

 bles. One large boulder of red granite, perhaps 6 feet in diameter, 

 I noticed amongst this stony stuff, resting on the top of a narrow 

 precipitous ridge jutting out into the sea, immediately south of the 

 Bullers of Buchan. 



To the north of the Buchan Ness the rocks sink down to a low 

 height, and in some places disappear, and the Pleistocene deposits 

 again show themselves. No good section is seen, however, except at 

 Invernettie, where a brick- and tile-work has long been established. 

 The excavations are made in the face of a bank, which rises up 

 from the sea-beach to a height of nearly 50 feet. I found its 

 structure to be as follows : — 



