240 PKOCEEDLNGS OP THE GEOLOGICAL SOCIETY. [Feb. 5, 



when occurring nearer to the surface ; and it is perhaps worthy of 

 notice that, not only Ketton stone, but all stone having its origin 

 in sedimentary deposition, is more enduring when in buildings it is 

 placed in the same horizontal position which it occupied in its 

 natural bed. If stone is placed in buildings with its planes of stra- 

 tification in a vertical position, the crush of superincumbent weight 

 will frequently split it ; and this not occurring, weather action will 

 probably scale the surface. Such phases of dilapidation are con- 

 stantly to be observed in stone window mullions ; in which, for the 

 sake of economy of time and material, the naturally horizontal 

 stratigraphical planes of the stone are perverted into a vertical 

 position. 



The Ketton quarries exhibit an immense area of broken ground ; 

 and, as no attempt has been made to level or restore the surface 

 after excavation, it is left in a perfectly useless condition — offering 

 a very unfavourable contrast to the admirable practice which 

 obtains in some parts of Northamptonshire, of restoring, after 

 quarrying, the surface to a state as good as, and sometimes, for the 

 purposes of cultivation, even better than, before. 



There are two places, not widely separated, where the Ketton 

 stone is quarried at this time — one an old working, called " the 

 Deeps," from which comparatively only a small quantity of stone is 

 obtained, but presenting the deeper section ; the other, more recently 

 opened, presenting a less deep but very lengthened section. The 

 latter is divided into several holdings or proprietorships ; a large 

 number of men are employed; and a great quantity of stone is 

 raised. 



In the " Deeps," the freestone underlies about 17 feet of the 

 Upper Estuarine Clays, divided into three beds of various character, 

 colour, and thickness, based by the usual ferruginous band. These 

 clays contain shelly seams ; some of which are characterized by the 

 presence of the small peculiar rostrated bivalve Necera Ibbetsoni, 

 Morris, and others by Cyrena, &c. Three beds of stone are exposed, 

 having an aggregate thickness of 11 feet : these consist of — a 

 coarse red Oolite, good Ketton freestone, and a very hard, sometimes 

 crystalline and blue-hearted, " Rag " stone. 



Details of Section at " The Deeps" Ketton. 



1. Upper Estuarine beds — 



ft. in. ft. in. 



a. Grey clay 3 



b. White clay 5 



c. Variegated clay 8 



d. Ferruginous band 9 



16 9 



2. Oolitic beds, Lincolnshire Limestone — 



a. Coarse red oolite 2 6 



b. "Freestone" — good Ketton Stone, Litna probos- 



cidea, frequent 3 6 



c. ' ' Eag " stone — sometimes blue-hearted , very glis- 



tening on fracture, in several courses 5 



11 



