BAGSHOT BEDS OF BAGSHOT HEATH. 55 



shot sections at Easthampstead Church, Bill Hill, and in the 

 Bracknell railway-cutting. 



The Ascot Hills, mapped as Lower Bagshot. In Dr. Irving's 

 section (vol. xliii. of this Journal) he shows a great thickness of 

 Upper Bagshot on these hills, the top of which he marks ' Goathurst 

 HjU,' and in 1888 he says " the Ascot Hills have a capping of 

 Upper [Bagshot] Sands, the base of which (about 300 feet O.D.) 

 etc." ^ The result of my investigations is to convince me that there 

 is no Upper Bagshot, but that there may very probably be a small 

 patch of Middle Bagshot on Goathurst Hill, and possibly another on 

 Long Hill. I feel, however, doubts about this, as it appears probable 

 that the patches of green sand which do occur are remains of Middle 

 Bagshot that once existed there but have been eroded away. 



In 1890 I saw a satisfactory section in a new reservoir, at the c 

 in ' Ascot Priory ' on the new one-inch map, and a quarter of a 

 mile south of the junction of the roads at Chavey Down, at the top of 

 the hill, 320 feet above O.D. It showed a considerable thickness of 

 gravel resting on yellow false-bedded sand, evident!}" the same bed 

 as that shown in the large sandpits close at hand, the sections in 

 which extend up to about 304 or 305 feet above O.D. The whole 

 is very clearly LoAver Bagshot. The top of Goathurst HiU, 667 

 yards JS'.E., is the same height as the reservoir, and on its western 

 slope there was at one time a brick-field. In this old brick-field, 

 310 feet above O.D., Mr. Herries and I found (March 17, 1888) . 

 some green sand. I think it was not in place, but probably had 

 come from the top of the hill, which is overgrown with vegetation. 

 It is only the topmost 20 feet which is obscure, and part of it is 

 gravel seen in old workings. There is no evidence of Upper Bag- 

 shot, but there is, I think, a small capping of Middle Bagshot. At 

 the bottom of the hill to the north there is an excellent Lower 

 Bagshot section, and there is another farther east opposite the 

 Eoyal Kennels, Ascot, 275 feet above O.D. In the latter the clay 

 layers are very well marked, and one is 3| inches thick. 



The above evidence makes it clear that there is no overlap of the 

 Upper Bagshot on the northern margin of Sheet YIII. of the Geo- 

 logical Survey map as claimed by Dr. Irving in the Geol. Mag. for 

 1887, p. 115 (2), nor any Upper Bagshot at Farley Hill,^ at Bear- 

 wood, Coppid Beech Lane (Buckhurst), Bracknell, or Goathurst Hill, 

 Ascot.^ I admit that there may be Middle Bagshot capping the 

 hills at Bracknell and Ascot. There is still the contention that 

 Middle Bagshot exists at Farley Hill, Bearwood, Wokingham, Coppid 

 Beech Lane, and Wick Hill, Bracknell, to be dealt with. Now, 1 

 admit that it is easier to distinguish between the Upper and Lower 

 than between either of them and the Middle Bagshot. The question 

 at present, however, is only between the Middle and Lower Bagshot, 

 and I would point out, to begin with, that at none of the places 

 above mentioned has any green sand been found. Not only are 



^ Quart. Journ. Geol. Soc. vol. xliv. p. 170. 



2 Ibid. p. 177. 



3 Ibid. vol. xHii. (1887) p. 388, diagram, fig. 2. 



