402 MR. BERT^AKD SJriTH ON THE [Sept. I 9I 2, 



22. The Glaciatiox of the Black Combe District (Cumberland). 

 By Bernard Smith, M.A., F.G.S. (Read March 17th, 1912.) 



[Plates XLI-XLIII.] 



Contents. 



Page 



I. Introduction 402 



II. Geological Struccure 405 



III. Pre-Glacial Condition of the District 407 



IV. The Maximum Glaciation 407 



V. (1) The Lake-District Ice 408 



(2) The Irish-Sea Ice 412 



VI. The Drift-Deposits of the Plain and the Adjacent Hill- 

 Slopes 412 



VII. The Lower Boulder Olav 416 



(1) The Coast-Sections 416 



(2) The Inland Sections 417 



VIII. Distribution of Scottish Boulders 420 



IX. Phenomena occurring during the Retreat of the Ice ... 421 



(1) Moraines and Trails of Boulders , 421 



(2) Marginal Channels and Associated Sands and 



Gravels 423 



(3) Sand and Gravel of the Plain 438 



(4) The "Which am-Valley and Duddon-Estuary Lakes. 441 

 X. The Upper Boulder Clay 445 



XI. Corrie-GIaciers , 445 



XII. Hanging Valleys 446 



XIII. General Conclusions 446 



I. iNiRODCCnON. 



Black Combe — a long whale-backed ridge of slate rising to a height 

 of 1969 feet — is situated a few miles south of the mouth of Eskdale, 

 and dominates the southward-trending extremity of Cumberland,, 

 which is separated from Lancashire by the Duddon valley and 

 estuary. The coast-line of Cumberland, from St. Bees Head to 

 Furness, is in the same latitude, and occupies a somewhat similar 

 position — with the exception of its trend — , as the Cleveland shoulder 

 of Yorkshire. 



While working upon the solid formations of this area four or five 

 years ago, my attention was diverted to the study of the superficial 

 deposits, dry rock-valleys, and other signs of glacial activity, which 

 presented many problems of great interest. The relations, for 

 example, between the Lake-District Ice and the Irish-Sea Ice are 

 well exhibited, and many of the glacial phenomena of the Isle of 

 Man are here repeated. 



My thanks are due to Mr. Herbert H. Thomas, Dr. J. E. Marr, 

 Mr. G. Barrow, and Mr. G. W. Lamplugh for valuable suggestions 

 and encouragement ; also to Mr. E. L. Guilford, who accompanied 

 me in the field, and placed many of his photographs at my disposal. 



