BAGSHOT BEDS OF BAGSHOT HEATH. 49 



sandpit near the railway-cutting described by Mr. E. S. Herries 

 and myself in 1886/ 



Unfortunately, neither Dr. Irving nor Mr. Hudleston say defi- 

 nitely in what manner they would treat the Goldsworthy section, 

 but I believe that Dr. Irving would include the whole hill in his 

 ' Lower Freshwater Series,' i. e., the Middle and Lower Bagshot 

 combined, and that Mr. Hudleston would retain the name ' Middle 

 Bagshot ' for everything down to the bottom of bed 4 and place all 

 below it (down to the Loudon Clay) in the Lower Bagshot. 



To readers who have not Prof. Prestwich's section at hand for 

 reference the following extract may be useful : — 



" b. Middle Bagshot Sands. ^®®*' 



"1. Coarse gi'eenish sand with a few flint pebbles 2 



" 2. Foliated sandy clays of various shades of brown 11 



"3. Grrey clay with traces of lignite 1 



"4. Grreen sand ; upper part light-coloured and clayey, the lower part 

 pure and dark-coloured. Numerous teeth and bones of fishes and 

 turtles, casts of Turritella sulcifera and Venericardia planicosta, 



&c 16 



"5. Compact lignite 1 



" 6. Light-coloured compact sandy clay, passing downwards into dark 

 grey clay. The upper part is irregularly pierced with green 



sand-tubes 6 



" 7. Light and dark brown and liver-coloured very compact foliated 



clays, with traces of vegetable impressions 8 



" c. Lower Bagshot Sands. 



Light yellow siliceous sands with irregular light-coloured argillaceous 



beds. Traces of vegetable impressions 130 



^' d. London Clay (upper part of)." 



Quart. Journ. Geol. Soc. vol. iii. (1847) pp. 382, 383. 



No doubt Mr. Hudleston's suggestion has this advantage : it 

 includes the clay with vegetable remains in the Lower Bagshot, 

 which I think we all agree is of freshwater origin, and leaves the 

 beds with the fish-remains and marine shells in a separate division. 

 If it were possible to draw a satisfactory line at bed 5 I probably 

 might not differ from Mr. Hudleston, but in my experience the clays 

 of beds 6 and 7 are so intimately connected with the green sands 

 containing marine shells that I feel bound to hold to Prof. Prestwich's 

 line of division and include the clays 6 and 7 in the Middle Bagshot. 

 The fact is that though more or less green sand always seems to 

 occur in the position of bed 4, it is in beds of a very irregular shape, 

 often running down into the underlying clays of bed 6, and in one 

 instance at least temporarily vanishing altogether; The best 

 illustration the writer has seen of the changeable character of these 

 beds was on and near the railway between Ascot and Bagshot. 



In the railway-cutting one mile south of Ascot Station there was 

 about 9 feet of dark green sand with casts of shells in abundance,^ 

 and in the brick-field a little to the north-west, close to the bridge 

 over the railway, the Middle Bagshot Beds have been dug for many 



^ Quart. Journ. Geol. Soc. vol. xlii. p. 414. 

 2 W. H. Herries, Geol. Mag. for 1881, p. 171. 

 Q. J. G. S. No. 189. B 



