Correspondence — F. L. Kitcldn cC; J. Fringle. 283 



As in other areas in the Lake District, the usual evidences of 

 glaciation cease about the 2,000 ft. contour, probably on account of 

 frost action during the latter part of the Glacial Period and since the 

 disappearance of the ice. During the period after maximum 

 glaciation, but before the ice was definitely confined to the present 

 valleys, its motion appears to have ignored the present drainage 

 system completely and evidences of cross-channels cut by these 

 high-level glaciers are very common on the mountain-tops. 



One episode in the later Glacial Period was the formrtion of a 

 lake in the Duddon Estuary, which, for some time, discharged its 

 water across South Furness into Morecambe Bay. Low Furness 

 is an area of deposition and is largely covered with Drift. This is 

 of two kinds : — 



1. The Irish Sea Drift, divisible into three horizons : {a) The 

 Upper Boidder Clay ; (b) the Middle Sands and Gravels ; (c) the 

 Lower Boulder Clay. These contain erratics from many places on 

 the west coast of Cumberland and probably still further north. 

 It has been fully described by Mackintosh. 



2. The Local Drift, a heterogeneous series of deposits, mostly of 

 limited extent, and probably with no simple relation to one another ; 

 certainly not divisible into three series, as has been claimed by 

 previous writers. The line of demarcation between these two drifts 

 nms across Low Furness from Dunnerholme to Newbiggin. North 

 of this line no erratics have been found which can be ascribed to 

 the Irish Sea Drift. 



CORRESPONDENCE. 



GAULT AND LOWER GREENSAND NEAR LEIGHTON BUZZARD. 

 Sir, — We have read Mr. G. W. Lamplugh's paper, " On the 

 Junction of Gault and Lower Greeiisand near Leighton Buzzard 

 (Bedfordshire)," which has recently appeared in the Geological 

 Society's Quarterly Journal (vol. Ixxviii, part i). Mr. Lamplugh's 

 main interpretation, violating, as it does, the most elementary 

 principles of zonal palaeontology and entailing the correlation with 

 one another of four distinct deposits of widely separate ages, 

 appears to us to be so fantastic as to be unworthy of serious con- 

 sideration. The fallacy of this attempted correlation must be 

 patent to all who arc acquainted with the faimal characterization 

 of the zones in question. Rock-specimens and fossils from these 

 beds may be seen at the office of the Geological Survey by any 

 geologists who are interested. The specimens provide clear evidence 

 that Lower Gault and Upper Gault have been confused by 

 Mr. Lamplugh, and no amount of special pleading will lessen the 

 force of their testimony. As regards the limestone-lenticlcs found 

 at Shenley Hill, amply shown by their fauna to be of Cenomanian 

 age, the matter is equally simple to those who are competent to 

 make a proper use of the evidence. 



