88 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Note on the Chalk-flints and Greensand/om/io? in Aberdeen- 

 shire. By W. Ferguson, Esq., F.L.S., F.G.S. 



Water-worn flints are found mingled with other pebbles for the 

 distance of about three miles along the shore north and south of Bu- 

 channess, on the eastern coast of iVberdeenshire ; especially between 

 the Black Hills on the north and Stirling Hill on the south, wherever 

 the rocks admit of a beach. Similar flints are found, though spa- 

 ringly, on Stirling Hill ; and they occur more plentifully on the 

 Black Hill and the neighbouring hill of Invernettie, almost covering 

 the surface ; they are traceable also along the ridge, of which these 

 last-mentioned hills are the eastern termination, at several points to 

 a distance of five miles inland from the sea. Here they occur at the 

 extreme verge of the parish of Old Deer, and are well seen upon the 

 farm of Bogingarry, on the estate of Kinmundy, where they are 

 closely packed in a clayey matrix, and contain numerous organic re- 

 mains, chiefly in the condition of casts and impressions. 



Near Peterhead also (not far north of Buchanness) flint-casts of 

 Echini and other fossils are very abundant. Flints are also found 

 on the surface of the hill of Skelmuir, adjoining Bogingarry ; and to 

 the south-west on the hill of Dudwick in the parish of Ellon. This 

 seems to be their southernmost limit. In these localities the flints 

 are angular. 



According to Mr. Christie* chalk-flints are found in the drift on 

 the high grounds between TurrifF and Delgaty Castle (Aberdeen- 

 shire), and among the shingle at Boyndie Bay, west of Banff. 



The Greensand was found at Moreseat, in the parish of Cruden, 

 south-west of Buchanness and about four miles from Kinmundy 

 above-mentioned. It was first met with in making an excavation 

 for a water-wheel ; and was again found about 400 yards to the 

 north-east of this point in digging a ditch to drain a field lately re- 

 claimed from the moss. Here it was from 1 to 3 feet below the 

 surface, and traceable in the ditch for more than 100 yards. The 

 ditch was 7 feet deep, and the section presented irregular layers of 

 unctuous tough clay, of a dark-brown colour and soapy feel, and 

 containing thin layers or patches of a compact sandstone. These 

 layers were not continuous ; they graduated into each other, thinned 

 out, disappeared, and reappeared most confusedly. They were much 

 inclined, dipping to the south. The whole mass had much the ap- 

 pearance of having been drifted ; although, from the nature of the 

 material, and the state of preservation in which the shells are found, 

 it does not appear as if it could have been transported far. The 

 sandstone is soft when newly dug, but hardens on exposure to air, 

 and becomes light-coloured in drying. When wet, it presents a 

 mottled appearance, the colouring being greenish ; when dry this 

 almost disappears. The exterior surface of the masses are reddened 

 with iron. 



Many of the organic remains in this sandstone are casts, and occur 



* Edinburgh New Philos. Journ. 1831, vol. x. p. 163. 



