140 



Dr. FiTTON on the Strata below the Chalk. 



(49.) Merstham. — The aspect of the amphitheatre formed by the outcrop 

 of the chalk and upper green-sand around this village is very characteristic : 

 a prominent ridge of the latter stratum^ passing from Blackditches to the 

 south of Gatton, in a nearly circular curve, above which the chalk downs rise, 

 with a similar curvature (see Plates VII. fig. 2., and X. a. No. 3.). Merst- 

 ham occupies nearly the middle of the line which has been worked upon for 

 firestone ; the extreme points to which the quarries have extended of late years 

 being near Godstone on the east, and Buckland Green on the west. The 

 village stands on the confines of the upper green-sand and the gault*, a 

 little to the soaith of an opening or gorge in the chalk, through which runs 

 one of the principal roads from London to Brighton. The beds dip at a 

 very small angle, towards the north ; and those which include the firestone 

 are visible to a thickness of about thirty feet, projecting like a step beyond 

 the foot of the chalk escarpment. The works had been discontinued for some 

 time before I visited the place; but the following list of the strata was given 

 to me by the person who had superintended themf. 



List of Beds at Merstham, Surrey. 



\_Lorver beds of the Chalk.~\ 



1. " Chalk." 



2. " Limestone." Grey marly chalk ; about 



3. " Burry chalk :" the " Craie Tiifau" of the French. This will not burn 



to lime, but goes to dust in the kilns 



[^Upper Greeu'sand.^ 



4. " Quarry stone ; " (Firestone) subdivided thus : 



a. " Roof" (sand 2 feet, soft stone 2 feet) ? Total, about 4 



This stratum is of great firmness and stability : the roof sup- 

 porting itself perfectly in the drifts worked into the hill, which are 

 30 feet wide. 



b. " Firestone;" including "_/Jw«5" (chert), about 2 feetfrom the top: about 5 



c. " Good hard building-stone." 2 



d. " Burry stone ; " about 16 



[^Gault.'] 



Feet. In. Feet. 



In. 



50 







50 







to 





60 







about 

 > 25 



5. "Marl." Gault: the apparent thickness of which, in this part of the 



country, agrees with that on the coast about 150 



All the beds become thinner towards the outcrop. 



* A well at the Feathers-Inn is 150 feet in depth, with a boring of GO feet at the bottom (in the 

 whole 210 feet), all in "clay" and "marl." The boring, Z\ inches in diameter, after going down to 

 60 feet, brought up such a quantity of water, that the well-sinker was drawn up in great haste, 

 and the water rose to within 40 or 50 feet of the surface. Much sand, which had come up through 

 the bore, was afterwards found in the bottom of the well. 



-j- A more full account of the Firestone pits here, has been published by Mr. Webster, Geol. 

 Trans., First Series, vol. v. p. Q55. 



