BAGSHOT STEATA FROM ALDEESHOT TO WOKINGHAM. 497 



to the north, the other to the south of the station, I am compelled 

 to differ somewhat from that which has been given to them in a paper 

 by Mr. Monckton lately published *. The upper pebble-bed, north 

 of the station, has been overlooked. The beds of the cutting to the 

 north of the station are represented as passing, with a southerly 

 dip, under the beds exposed in the cutting to the south of the sta- 

 tion. This, however, would give to the Middle Eagshot series a 

 much greater thickness than they are found to have in any known 

 section in this district. At the northern end of the northernmost 

 of the two cuttings nearly the wkole of the Middle series is exposed ; 

 the sequence of the beds and their several thicknesses (except that 

 of the lowest clay-bed, which is only exposed at the bottom of the 

 valley to the north) correspond with the sequence and thicknesses 

 of the beds (Xos. 3-9) in the well-section (fig. 1). Mr. Monckton, 

 in the paper just referred to, has stated that the thickness of the 

 beds of green sand (E. p. 350, he. cit.) is not shown; yet I 

 have been able to measure it, and find it to correspond very nearly 

 with that of the beds of precisely the same character (Nos. 7, 8) in 

 fig. 1. He has also stated that in the cutting to the north of the 

 station the beds are "brought into the cutting by a fall of the line." 

 Having taken observations with a spirit-level all along the cutting, 

 I am unable to verify the statement, and the " fall " here referred to 

 seems to be unknown to the plate- layers employed on that part of 

 the line. 



In the cutting to the south of the station, only the beds Nos. 3-5 

 of fig. 1 are exposed. The clay-bed of the northern cutting passes 

 under the station, and comes up again in the southern cutting, 

 rolling over to form a slight anticline, as we proceed south, until it 

 again disappears near the bridge, about half a mile to the south of 

 the station. The sequence, character, and thickness of the beds 

 are the same as in the northern cutting, except that the green sand 

 (No. 7) is not exposed. The upper pebble-bed occurs in precisely 

 the same position, and its identity with the bed No. 3 of fig. 1 has 

 been directly proved, within the last two years, by the deep trench 

 made for the new main sewer of the College, the bed of well-rolled 

 flint-pebbles imbedded in a stiff loam having been exposed continu- 

 ously from the railway-cutting right up to the College, a distance 

 of nearly half a mile. The facts furnished by this section will be 

 best understood by reference to the accompanying diagram (fig. 2). 

 At and immediately about the station the pebble-bed (jSTo. 3) 

 appears to have been much attenuated, and to have been recon- 

 structed as later drift, the pebbles being mingled with a few angular 

 discoloured fragments of flint, such as form the chief ingredient of 

 the later drift-gravels of the higher parts of the country. In the 

 cuttings, however, both to the north and to the south of the station, 

 the original Bagshot pebble-bed has remained intact. On account of 

 the water-logged condition of the beds in this syncline, piles had to 

 be driven to get a foundation for the station. 



To the east of the railway, in the brick-field, and in the arable land 

 ^ Quart. Journ. Geol. Soc. vol. xxxix. p. 351. 



