143 



THE ICE=BORNE BOULDERS OF YORKSHIRE. 



J. H. HOWARTH, J. P., F.G.S. 



{Contimied from page 99). 



There have been three directions of source, or at any rate, 

 three principal directions of source. 



In his paper on ' A System of Glacial Lakes in the Cleve- 

 land Hills,' in the ' Quarterly Journal of the Geological Society,' 

 (vol. Iviii.), Professor P. F. Kendall describes these directions as 

 * Western,' ' Northern,' and ' Eastern.' These terms are 

 accurate, clear, and easily understood, and are adopted here. 



THE WESTERN GROUP. 



These include rocks from Cumberland and Westmorland^ 

 and from the Upper Tees Valley. The rocks recorded herein 

 are ^'erv widely distributed in Yorkshire. 



The description given by the writer in ' Notes on Boulder 

 Markings/ * may be repeated here, with certain later records 

 also included. 



The ' Western ' Group rocks range all along the East coast,, 

 down into Lincolnshire, and inland from tlie coast to elevations 

 of over 800 feet, O.D., and to 30 to 120 feet below the surface 

 (Shap Granite) in borings at North Ormesby, near Teesmouth. 



They occur spread over the central plain of the Vale of 

 York, from the Tees to Doncaster, Tickhill, and Bawtry ; 

 abutting against the Hambleton Hills on the east,, 

 and reaching to five miles west of Ripon on the west. 

 They occur also plentifully in the Valley of the Yorkshire 

 Calder, fr{)m Todmorden to below Wakefield. They are also 

 in the Valley of the Dearne, but under a certain amount of 

 suspicion as to details, since human aaency is known to have 

 at least contributed. They are, however, certainly at Stain- 

 cross, at the end of the Dearne Valley above Barnsley. 



These rocks reached Yorkshire by two principal and widely 

 divergent routes. Those of the east coast and the Vale of 

 York are traceable up the Tees valle}'^ to just below Middleton- 

 in-Teesdale, and over the higher pass of Stainmoor (1800 feet), 

 to Brough, in Westmorland ; thence to Wastdale Crag (the 

 Shap Granite outcrop), to the Permian area around Penrith, 

 to Eycott Hill and Carrock Fell, in Cumberland ; to Threlkeld, 

 St. John's Vale, Armboth and Skiddaw ; and to the further 



* Proceedings Yorks. Geol. Soc, vol, xv., pt. i, p. 46. 

 1908 April I. 



