506 LOWER OOLITIC KOCKS OF ENGLAND : 
Over the plain of Lincolnshire Limestone, east of Navenby, Wadding- 
ton, and Bracebridge, there is a large area of the formation uncovered by 
Drift. Where the upper beds occur at Blankney and Metheringham, 
"very powerful springs occur," according to Mr. De Ranee, and he 
remarks that " the line of permanent saturation occurs more than a mile 
west of the overhanging lip of impermeable rocks," at Great Spring 
Head, to the S.W. of Dunston. The wells that supply the district 
appear to be shallow. Estimating the thickness of the Lincolnshire 
Limestone at 65 feet, Mr. De Eance considers that about 26 feet of this 
is permanently saturated with water, and that a pumping station by 
the railway, south of Dunston Station, might be expected to produce, 
in dry years, the daily quantity of 700,000 gallons of water.* (See Fig. 60, 
p. 215.) 
Lincoln is supplied from springs and rainfall collected from a gather- 
ing-ground of about 2,000 acres ; and 700,000 gallons can be supplied 
daily. 
At Sudbrook Holme, a well sunk through the Kellaways Beds and 
Great Oolite Series to the Lincolnahire Limestone, to a depth of 106 feet,, 
yielded 7,000 gallons a day.f 
Mr. De Eance states that a boring 106 feet deep, on the west side of 
Dunholme, was carried into the Lincolnshire Limestone, and water rose 
5 feet above the surface, the yield being 20,000 gallons per day. 
At Welton there are strong springs, one being marked on the mat) as 
the " Old Man's Head Spring." These springs, as stated by Mr. De 
Ranee, show marked fluctuations according to the rainfall, proving the 
rapid circulation of water through fissures in the Lincolnshire Limestone. 
Thus the amount of water, as gauged by Mr. Teague, has varied from 
105,000 gallons to 2,800,000 gallons (after heavy rainfall). J 
The danger arising from inattention to the drainage and the consequent 
pollution of well-waters, was shown some years ago at Winterton. 
Great Oolite Series. 
On the Fuller's Earth clays there are comparatively few villages, though 
in Dorsetshire where the Upper Greensand rests on these beds, springs 
are thrown out and we find a number of small villages. More suitable 
situations were found on the Fuller's Earth Rock, as at Maperton, Purse 
Caundle, and Thornford ; and water was formerly obtained from this 
formation in the lower part of Frome. 
The Fuller's Earth is not always- of an impervious character. Lycett 
remarks in reference to the Cotteswold area that " The experience of well- 
sinking fully illustrates the same fact, for it sometimes happens that after 
passing through the Great Oolite, when the clay is reached, the pound as 
it is termed by the operatives, destined to retain the water is permeable, 
rendering further sinking necessary until a more compact bed is attained, 
and it has occasionally been necessary to penetrate the marls 30 or 40 
feet ere this has been accomplished." || In illustration of this, the follow- 
ing section of a well at Prior Park, Bath, recorded by De la Beche, may 
be quoted, as it " shows the water retained by clay beneath the great 
oolite limestone "^[ : 
FT. 
f Loose Rock - - - - 20 
&*?* ^Oolite 20 
Oolite. L Hard freestone - - - - - 20 
- ..-. -JO 
Water - - - - - 100 
* Prgc. Yorksh. Geol. and Polyt. Soc., vol. xii. pp. 29-31. 
t Geology of Lincoln, p. 196. 
J Proc, Yorksh. Geol. and Polyt. Soc., vol. xii. p. 32. 
See Keport, Domestic Water Supply, p. 179. 
|| The Cotteswold Hills, p. 88. See also Witchell, Geol. Stroud, p. 70. 
IT Report on the state of Bristol, Bath, Frome, &c. (Health of Towns Commis- 
sion), 1845, pp. 37, 49. 
