Vol.51.] RAILWAY-CUTTINGS NEAR KESWICK. 493 



33. Notes on some Eailway Cuttings near Keswick. 

 By J. Postlethwaite, Esq., P.G.S. (Read May 8th, 1895.) 



[Abstract.] 



Several cuttings have recently been made on the Cockermouth, 

 Keswick, and Penrith Railway, chiefly through drift, though some 

 occur in the Skiddaw Slates, and in one case a diabase dyke (much 

 decomposed) was met with. It is similar in character to a rock 

 exposed about | mile west of Troutbeck. 



The Author describes the drifts as blue clay beneath, and brown 

 clay above, and considers that these two clays were produced during 

 two separate periods of glaciation, with no long interval between. 

 In some places near Keswick water-borne gravel may be seen 

 surmounted, by blue clay ; this gravel is considered by the Author 

 to be of fluviatile origin. A section at Keswick Station is described ; 

 it is 130 yards in length, with a slight break in it, 50 yards of the 

 western end being cut back 9 feet to the north. At the point 

 where the break occurs, and for 17 yards eastward, some beds of 

 current-borne materials take the place of the lower part of the blue 

 clay. There is a bed of a very fine brown sediment 1 foot thick ; 

 above it is 2 feet of fine sand, and above that a bed of coarse gravel 

 and pebbles, which is succeeded by blue clay of the usual type. 

 The whole of these beds dip south-west, at an angle of about 9°. 



Tho Author has searched both blue and brown clays diligently 

 for shells, but hitherto without success. 



Discussion. 



Mr. Marr said that he knew the igneous rock occurring near 

 Troutbeck Station ; it was one of the most rotten rocks in the 

 district. His examination of the brown and blue clays described in 

 the paper led him to infer that the ' brown clay ' was merely the 

 weathered condition of the blue clay. With regard to the gravel- 

 deposits mentioned in the paper, he would say little, but each gravel- 

 deposit in the district required explaining, for the various gravels 

 had very different methods of origin. 



Dr. Hicks was also inclined to believe, from evidence in North- 

 west Middlesex, that much of the brown clay was merely weathered 

 Chalky Boulder Clay, and this had often been mistaken for London 

 Clay ; indeed large areas supposed to show on the surface true London 

 Clay were entirely mantled by this weathered Boulder Clay. 



Dr. Hinde also spoke. 



