450 



THE GEOLOGIST. 



conglomerate on the Maidstone hills, near the sites of the ' grey 

 wethers.' " 



The statement of the late Dr. Mantell still holds good, that "no 

 regular stratum of the ' Druid sandstone ' has yet been discovered 

 in this country, and its geological position is still undetermined." 



■; ; Preston Quarry, on the south side of 



.ol _J.,__.=._J,^,.,,..^^ the Medway, ofters a fine section of the 

 ^ ■'^^ effects of an elevating force, as may be 



seen in the accompanying sketch (fig. 

 11). The stone is fractured in all di- 

 rections, and consequently large blocks 

 are not obtainable. The diagram, fig. 12, 



. , . -n ^ ejives the continuation of the disturbed 

 Fig. 11.— Auticlinal at Preston & , ^ 



Quarry. « ^, black greys ; b b, , e .^ 



molluskite bed; c c, loamy clay The most interesting part of the 

 and greeusand, witb beds of stone quarry is the bed of loamy clay, C C. It 

 bored with lithodomi at c' ; d, about three feet in thickness, and 

 surface falling to the Medway. contains fragments of shells— oysters, 

 terebratulge, corals, etc. In detached pieces, with their edges rounded, 

 is a layer of stones, varying in thickness of about 2 inches by 6 or 



Preston Quarry. 



Medway. 



Fig. 12. Section of Preston District. 



12 inches across. Their upper surfaces {o' c') are perforated by litho- 

 domi, and the perforations are filled with the loam and a white pow- 

 dery deposit. The excavations are about 2 inches in depth ; and one 

 fragment is so perforated, that not a square inch of it remains intact. 



COEEESPONDENCE. 



Origin of Flint in ClialJc. 



Deae Sie, — Fhnt in chalk is found as bands of nodules or thin seams 

 separated from each other by intervals of chalk varying from a few feet to 

 many yards ; the nodules, from a boy's marble to two or three feet in 

 diameter. In some pits only solitary flints occur here and there ; in others, 

 in tlie same upper flint-bearing chalk, there are no flints at all. 



We liave terebratulse composed of pure flint extracted from blocks of 

 equally pure chalk. 



I consider it very doubtful whether the flints have been deposited suc- 

 cessively with tlie beds of chalk. Flint nodules, it appears to me, are 

 actually in process of increase at this day. Yours truly, 



EOBT. MOETIMEE. 



Fimhcr, Malton, November lotli, 1862. 



