File:The Quarterly journal of the Geological Society of London (14076469775).jpg

■ BAGSHOT STRATA FROM ALDERSHOT TO WOKINGHAM. 505
At St. Paul's rector.' two wells were dug a few years ago by my
friend the E-ev. J. T. Brown. Commencing at about the same level
with both wells, which are only a few yards distant from one
another, in one well 25 feet of butf-yellow sand was passed through,
and then a copious su.3ply of good water was obtained at the top of
the London Clay ; in the other a mere layer of yellow sand was
passed through, when the " blue clay " was pierced and penetrated
to a depth of 135 feet. This fact seems to admit of no other
explanation than pronounced erosion of the Loudon-Clay surface
beneath the Bagshot Sands of the Wokingham outlier.
Just north of Wokingham station there is another exposure of
Bagshot Sands, which agree in character with the loamy sands of
the bed jS'o. 4 of figs. 1 and 2, to which reference has been so often
made. The sands are exposed just below St. Paul's church. Im-
mediately to the north of the bridge over the railway, the London
Clay with septarian nodules comes in at the bottom of the cutting,
and rises as we advance northward along the cutting until the
overlying sands disappear. Yet the stratification of both the Bag-
shot Sands and the London Clay is horizontal, as proved for the
former in the section below the church, for the latter in Mr. Phillips's
brickyard just below. Here, then, we have a case of the Bagshot
Sands (whatever particular horizon they may occupy in the Bagshot
Series) deposited against a denuded shelving shore of the London
Clay, unless we assume the presence of a fault hading at a very low
angle. This is more clearly expressed in the adjoining diagram
(fig. 4).
Pig. 4. — Section in Cutting north of Wohingham Station.
.S. S".
a, Bagshot Sand. b. London Olay-
10, Bracknell. — Bracknell station (on the South-western Railway)
is 250 feet above O.D. level. In the long cutting east of this station
beds of the Middle and L^pper Bagshot Sands are exposed.
ft.
£?. Buff-yellow sands 10-15
c. Bed of flint pebbles imbedded in sand 1
b. Yellow loamy sand 6
a. Dark black and green clay (exposed) 4
The lowest bed .a) here exposed gave much trouble in making
the cutting. Being water-logged, it caused numerous " slips," so
that rushes had to be planted along the bottoms of the cutting-
slopes to give them security. The altitude of the pebble-bed at