282 Reports c& Proceedings — Yorkshire Geological Society. 



of cassiterite illustrated by a series of drawings of microscopic 

 sections ; lie noted that all sections lie had examined showed the 

 cassiterite to possess cleavage. 



" Ancient Documents relating to Cornish Mining." By F. J. 

 Stephens, F.G.S. 



In which he advocated the possibility of profitable lead deposits 

 'still existing in Coriiwall. 



" Note on a Pegmatite from Cam Marth." Bv E. H. Davison, 

 B.Sc. 



Who described a pegmatite which had recently been exposed and 

 which showed crystals of orthoclase showing Baveno twinning, and 

 crusted with secondary mica on which occurred crystals of tourmaline, 

 purple fluor, blue apatite, etc. The field relations of the pegmatite 

 were described and the genesis of the minerals indicated. 



" The Geology of Godrevy." By C. Frazier (student of the 

 School of Mines, Camborne). 



In which the writer described the geology of the Godrevy area and 

 gave assay results of the manganese and gold value of the manganese 

 layer in the raised beach of Pleistocene age. 



A prize of £5 was awarded for this paper fiom the proceeds of the 

 Bolitho Fund. 



" The Geology of Worras Hill, St. Ives." By A. H. E. Turner 

 (student of the School of Mines, Camborne). 



The writer described the geology of Worras Hill and some types 

 of altered granite occurring there. He also dealt with the micro- 

 scopic characters of the igneous rocks and their altered forms. 



" Fossils near Bude." By F. M. H. Stephens (age 14). 



In which fish and plant fossils were described as well as some 

 concretions of clay ironstone which occur in the Culm Measures 

 near Bude. 



YoRKSiiiEE Geological Society. 

 29th March, 1922. 



" Some new Observations on the Glacial Geology of Furness." 

 By Geo. Grace, B.Sc, and F. H. Smith, B.Sc. 



To a great extent the topography of High Furness is the result of 

 abnormal erosion during and immediately after the Glacial Period. 

 The series of events that produced the basin-like depression in part 

 of which Coniston Lake lies were described in detail, and it was 

 shown that it originally consisted of two distinct valleys at over 

 300 feet O.D., and that its present condition is due to the erosion of 

 ice coming down Church Beck and Yewdale, assisted by that from 

 several smaller valleys to the north-east. 



This origin is confirmed by the profiles of the various becks which 

 run into it, all of which occupy hanging valleys. Many areas in the 

 valleys and much of Low Furness were eroded below sea-level, and 

 the greatest depth seems to be somewhere about 200 feet below O.D. 



