Yol. 59.] A NEW BOEING AT CAYTHOEPE. 29 



3. On a new Boeing at Caythoepe (Lincolnshiee). By Henry 

 Preston, Esq., E.G.S. (Bead November 5th, 1902.) 



Dtjring the early part of the present year (1902) a boring was 

 made near Caythorpe, for the purpose of obtaining a water-supply 

 from the Marlstone Koek-bed of the Middle Lias. The work was 

 done for Mr. E. Lubbock, of Caythorpe Court, and the boring is 

 about a third of a mile east of the house. A well has been dug to 

 a depth of 46 feet, and from the bottom of this well a 6-inch boring 

 was put down. The thickness of the L T pper Lias in this district is 

 usually taken to be about 110 feet, but the present boring has shown 

 it to have here a thickness of 199 J feet. The section is as follows : — 



Thickness. Depth. 

 Feet. Feet. 



Surface-deposits { Sand "and ydlow clay ZZZ. l\ U 



Northampton Sands ... Ferruginous limestone 4f 9 



j~ T ("Blue clay, with layers of 



L pper .lias , | concretionary nodules 199| 208^ 



Marlstone Dark greenish-blue limestone. 19^- 228 



, r T \ Hard silly clav, greenish in 



Middle Liassic clays .< -. J -, - ' ? . i. oi omi 



[ colour, sancty and micaceous. to 3^ 231f 



The rest-level of the water in the borehole is at a depth of 175 

 feet from the surface, or 145 feet above Ordnance-datum. 



The boring was made by Mr. J. E. Noble, of Thurlby, near Bourne, 

 under my own superintendence, and samples of boring-debris were 

 sent to me at frequent intervals. Previous to this boring being 

 made, four other wells had been sunk, which passed through the 

 limestone and into the Liassic clay. The positions of these wells 

 are shown on the plan (fig. 1, p. 30). 



The normal dip of the beds is south-easterly, and, as will be 

 noticed, Wells Nos. 1, 3, & 5 lie approximately in the line of dip, 

 and in continuation of the lower part of the road ; and hence a 

 section (fig. 2, p. 30) taken along this road and through Wells Nos. 1, 

 3, & 5, gives the contour of the Upper Lias. This contour shows 

 that the limestone lies irregularly on the clay, and has a decided dip 

 towards the west, a direction opposite to the normal dip. It would 

 thus appear that the limestone has settled down from some cause, 

 upon the eroded surface of Upper Liassic clay, and has masked the 

 true thickness of this clay. 



In searching out the cause of this settling down of the lime- 

 stone, it must be mentioned that a spring crops out by the 

 roadside, just at the junction of limestone and clay. This is 

 one of the ordinary overflow-springs, somewhat common along 

 the western face of the escarpment; and although the spring is 

 a small one, it has the reputation of continuing to flow for the 

 greater part of the year. The mere fact that it is continuous in its 

 flow would suggest that some alteration of strata has taken place, 

 whereby the area of its gathering-ground is increased; but it is 



