Sep.. 1891. 
BORING AT SHILLINGFORD. 
201 
ON A BORING AT SHILLINGFORD, NEAR 
WALLINGFORD (ON THAMES). 
By A. J. Jukes Browne, B.A., F.G.S. 
The site of this boring is at Mr. Field’s Brewery at 
Shillingford, a small village on the Oxford side of the Thames, 
two miles north of Wallingford, and about ten miles south-east 
of Oxford. Thus, although the boring is outside the limits 
of the London basin, it is in the valley of the Thames, and has 
a certain bearing on the subterranean geology of the London 
basin, inasmuch as it is at present the nearest point west of 
Richmond where the Lower Greensand in its normal facies 
has been proved to exist. 
The results of the boring are, in fact of interest, on two 
accounts :—(1) It enables us to ascertain the thickness of the 
several formations which lie between the Malmstone Beds of 
the so-called Upper Greensand and the Oxford Clay at a point 
which is eight-and-a-half miles from the nearest outcrop of 
the latter ; (2) it is remarkable for having passed through 
two water-bearing deposits without having obtained a satis¬ 
factory supply from either, though both are strata from which 
such a supply was to be expected. 
The boring operations were conducted throughout by 
Messrs. Isler and Co., to whom, and to Mr. Field, I am 
indebted for the information on which this communication is 
based. 
The work was commenced in 1885, and the boring 
was rapidly carried through the Gault into the Yectian 
(Lower Greensand), where a plentiful supply of water was 
found, but unfortunately it contained so much sodium chloride 
as to be unfit for use. When the boring had reached the 
Kimeridge Clay, Messrs. Isler applied to the Geological Survey 
for information as to the probability of obtaining a better 
water supply at a greater depth. They were informed that 
the thickness of the Kimeridge Clay would probably be 
between 100 and 150ft., and that after passing through a 
certain thickness (possibly 20ft. or 30ft.) of limestone, a good 
supply of water might reasonably be expected from the sands 
which would occur below, if the succession was the same as 
that on the outcrops about eight miles distant. 
On the strength of this opinion, boring was recommenced 
in March, 1886, and continued till at a depth of 375 feet sand 
was reached, and water found, which, however, did not rise 
further than to 60ft. below the surface. Moreover, the sand 
was only a thin bed, and at 379Jft. the tools entered a dark 
