Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/122

 48 PROCEEDINGS OF THE GEOLOGICAL SOCIETY.

POSTPONED PAPERS.

On Flint Flakes from Carrickfergus and Larne. By G. V. Du Noyer, Esq., of the Geological Survey of Ireland.

(Communicated by Sir R. I. Murchison, Bart., K.C.B., F.G.S.)

[Read June 17, 1868*.]

[Abridged.]

On the 3rd of March last I had the honour to address a letter to the Director-General of the Geological Surveys of Great Britain, Sir Roderick Murchison, Bart., K.C.B., on the subject of worked flint flakes from the " drift " of the Belfast district, of which the following is an extract : —

These worked flint flakes, of which I send a typical collection to the Museum in Jermyn Street, were picked up by me, during the progress of my geological work last summer, from the gravelly drift and subsoil clay of the districts around Carrickfergus, Larne, and Belfast, in the co. Antrim, and Holywood and Bangor, in the co. Down.

I enclose a list and descriptive catalogue of these flint flakes, which I believe are capable of being subdivided into eleven groups, placing the rudest form of flake in the first.

When these singular implements were discovered, some four or five years ago, in the co. Antrim, along the chalk escarpment, their mechanical origin was questioned ; indeed, I thought at first that their primary origin might possibly be due to the natural crushing of the flint nodules, which occur as a conglomerate enclosed in a red or haematitic paste, resting on the subaerially eroded surface of the chalk, and therefore directly interposed between it and the basalt, — granting at the same time that the chippings round the edges of the flakes were artificial.

Subsequent examination into the subject, however, clearly showed me that every flake, no matter how rude its form, provided it exhibited that conchoidal fracture called the bulb of concussion at any of its edges, is certainly artificial ; indeed I have succeeded in making flakes, of the primary form myself, showing this peculiar conchoidal fracture.

Journ. Geol. Soc. vol. xxiv. p. 484.
 * For the other communications read at this Evening Meeting, see Quart.