Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/531

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6. On the Correlation, Nature, and Origin of the Drifts o/ Northwest Lancashire and a part of Cumberland, with Remarks on Denudation. By D. Mackintosh, Esq., F.G.S.

Contents.

1. Introduction.

2. Coast-section of Drifts at Blackpool. a. Upper Boulder-clay. b. Middle Sand and Gravel. c. Eagberg " Rockery." d. Lower Boulder-clay and Loam. e. Postglacial Deposits. f. Origin of the Blackpool Drifts.

3. Drifts between Lancaster and Carnforth. a. Derivation of Limestone Boulders.

4. Denudation of Drift Deposits. a. Origin of Lake- and Swamp-basins in Drift. b. Subaerial Denudation of Drift Deposits. c. Origin of Drift Escarpments and Valley- plains.

5. Smoothed Rock-surfaces and Drifts of the Furness peninsula. a. Distinction between Glaciated, Rain-worn, and Sea-worn Rock-surfaces. b. Rockwork of Birkrigg Moor and Hampsfell. c. Glaciated Rock- surfaces Ulverstone. d. Lower Boulder-clay or " Pinel " between Bardsea and Bay-cliff. e. Pinel and Contorted Sand and Gravel near Ulverstone. f. Contorted Sand and Gravel in other parts of the Furness peninsula. g. Pinel at High Levels. h. Upper Boulder-clay. i. Drift Capping of Dunnerholme. j. Upper Boulder-clay at Barrow. k. Surface Boulders. l. Sections obtained by Borings near Ireleth.

6. Drifts of Whicham Valley and Blackcombe.

7. Direction and Derivation of the Flow of Granitic Drift in Northwest Lancashire.

8. Connexion between Boulder-drifts and Superficial Accumulations at High Levels.


1. Introduction.

Are the drifts of different districts merely local variations of one great formation which cannot he systematically divided? or can these deposits in their more persistent features be satisfactorily synchronized over extensive areas ? As this is a very important question, and as little or no notice of any attempt to classify or correlate the drifts of the north-west of England has yet been communicated to this Society, the author hopes that the following account of observations made during prolonged visits to Blackpool, Ulverstone, and Lancaster in 1868-69 may not prove unacceptable.

2. Coast-Section of Drifts at Blackpool.

There are perhaps few parts of England where such extensive and instructive sections of distinct kinds of drift are clearly exposed as in the immediate neighbourhood of Blackpool. Beyond an acquaintance with the fact, derived from the Geological Magazine*, that Mr. Binney, F.R.S., had found sea-shells in, and had written on these drifts about eighteen years ago†, when the triplex division of drift

  • Mr. Darbishire on " Drift-beds," vol. ii. No. 7, July 1865.

† Memoirs of the Lit. and Phil. Soc. of Manchester, vol. x.