134 Geological Society : — 



He discusses their relationship with other drifts, and arrives at 

 the following conclusions : — 



1. The glacial deposits are divisible into Upper and Lower 

 Boulder Clay, with an Intermediate series. 



2. The Lower Clay is a continuation of the Basement Clay of 

 Holderness, and is the product of the first general glaciation of the 

 area. The Intermediate series passes laterally into the Purple Clays 

 of Holderness, and has been deposited at the edge of the ice-sheet. 

 The Upper Clay includes the Hessle Clay of Holderness, and marks 

 the latest glaciation of this region. 



3. The fossiliferous beds of Sewerby (" Buried-cliff Beds ") and 

 Speeton (" Estuarine shell-bed ") are older than the Basement Clay, 

 and therefore than the earliest glaciation. 



4. The glaciation was effected by land-ice of extraneous origin, 

 which moved coastwise down the North Sea, and did not overflow 

 the greater part of the Yorkshire Wolds. 



5. Neither the Boulder Clays nor the Intermediate gravels are of 

 marine origin, the shells which occur in them being derivative. 



6. The ice-sheet seems to have filled the North-Sea basin in this 

 latitude from the commencement of the glaciation until its close. 

 There is no clear evidence here for a mild interglacial period, but 

 only for extensive fluctuations of the margin of the ice. 



3. " On a Phosphatic Chalk with Belemnltella quadrata at 

 Taplow." By A. Strahan, Esq., M.A., F.GkS. 



Two beds of brown chalk in an old pit near Taplow Court owe 

 their colour to a multitude of brown grains. These grains are almost 

 entirely of organic origin, foraminifera and shell-prisms forming the 

 bulk of them. Mr. Player has analysed specimens of the brown 

 chalk, and finds that it contains from 16 to 35 per cent, of phos- 

 phate of lime. The tests as well as the contents of the forami- 

 nifera seem to have been phosphatized, the phosphate appearing as 

 a translucent film in the former case, and as an opaque mass in 

 the latter. In the case of the prisms of molluscan shells, the whole 

 of the phosphate appears to be in the opaque form. Minute 

 coprolites also occur, together with many small chips of fish-bone, 

 in which Dr. Hinde has recognized lacunas, while some have been 

 identified by Mr. E. T. Newton as portions of fish-teeth. 



Mr. Player observes that the phosphate occurs in such a con- 

 dition that it would not improbably serve as a valuable fertilizer, 

 without conversion into superphosphate. This condition is probably 

 due to the partial replacement of carbonate of lime by phosphate 

 in the organisms. The removal of the remaining carbonate leaves 

 the phosphate in a honeycombed state, peculiarly favourable for 

 attack by the acids in the soil. 



The author comments upon the resemblance of the deposit to the 

 phosphatic chalk with Belemnitella quadrata which is largely worked 

 in Northern France, and upon a less striking resemblance with that 

 of Ciply, which is at a higher horizon. 



