282 Reports and Proceedings — Geological Society of London. 



in Cambridgeshire, a curved line a little below the crest of the 

 Upper Chalk escarpment. The author in 1902 found evidence 

 which satisfied him that the disturbances, previously supposed to be 

 an anticline, were due to glacial action, a view confirmed during 

 the present year. Four sections are described : Great Chishall, 

 Pinner's Cross, the Limekiln south-west of Newsell's Park and north 

 of Barkway, and north of Eeed. The disturbed Chalk near Royston, 

 with its fractured and displaced flints, occurs in conjunction with 

 Boulder-clay, and the latter is found beneath a considerable thick- 

 ness of disturbed Chalk. This is compared with similar phenomena 

 near Trimingham, and at Litcham in Western Norfolk. While 

 Boulder-clay occurs along the high ground bounding the disturbed 

 area to the south, the vale and undulating downs immediately to 

 the north are devoid of this Glacial Drift. The facts were to be 

 explained, on the land-ice theory, if the ice were at first welded to 

 the rubbly surface strata in regions north of the escarpment, and, 

 when movement set in, there were overthrusts of debris-laden ice, 

 and upper layers of ice were rent asunder from and moved over 

 lower ones ; while to the thrust or long-continued pressure of ice 

 along shear-planes at the higher levels may be attributed the belt 

 of disturbed strata. Certain patches of esker-like gravel in 

 Wardington Bottom might be explained by streams due to the 

 melting of the ice banked up against the scarp ; and we might go 

 some way with Sedgwick in believing that the outlines of the 

 combes " do not appear to have been produced by a long-continued 

 and slow process of erosion ; but rather to have been cleanly swept 

 out by rapidly descending water-floods." 



2. " On a Section at Cowley, near Cheltenham, and its bearing 

 upon the Interpretation of the Bajocian Denudation." By Linsdall 

 Richardson, Esq., F.G.S. 



According to Mr. Buckman's map, published in 1901, the Upper 

 Trigonia Grit should have been seen at this spot to rest directly, 

 and non-sequentially, upon the Upper Freestone, whereas obser- 

 vation shows the intervention of at least the Buckmani Grit, part 

 of which thins out from 4 inches at the north-eastern end to nothing 

 at the other end of the quarry, which is in the direction of the 

 anticlinal axis. The error is not one of fact, but of inference, and 

 the present evidence rectifies portions of those limits which were 

 drawn theoretically. A section near the "Air Balloon " Inn, on the 

 road from Birdlip to Cheltenham, shows the Lower Trigonia Grit 

 covered by Buchnani Grit and underlain by the Upper Freestone. 

 There is only one section where the Upper Trigonia Grit is seen 

 to rest directly upon the Lower Trigonia Grit, the latter being only 

 3 feet 2 inches thick. The causes producing the Bajocian denudation 

 appear to have been forces so acting as to effect a repetition of 

 flexure along old lines of weakness (Aalenian) ; and thus in the 

 Birdlip area an anticline maybe again located, but the elevation was 

 this time much greater : indeed, the level of the Aalenian denudation 

 was passed by the Bajocian. Other sections near Brimpsfield and 



