﻿Vol. 64.] CHANNEL OF DKIFT AT HITCHIN, 19 



The last boring was made afcHolwell Bury for Mr. Kenneth. Its 

 site was about a quarter of a mile west of the main road to Bedford, 

 180 feet above sea-level, and nearly 2 miles directly north of that 

 at Ickleford. It is well outside the indentation of the escarpment, 

 and is just south of the point where the Gault should come to the 

 surface ; but the position of the outcrop is quite obscured by a 

 thick deposit of Boulder-Clay. Chalk-Marl is seen half a mile to 

 the south-west and nearly a mile away to the east. Between these 

 two borings a curious elongate, boss of the Lower Chalk rises to the 

 surface. Mr. Kenneth kindly sent me the following particulars : — 



Jhickness. Depth in feet. 

 Surface-soil and Boulder-Clay : water at 95 feet. 98 98 



Shingle 4 102 



Sand 19 121 



Sandyclay 12 133 



Gault bored 205 338 



The water-bearing strata at 95 feet seem to me to be the same 

 as these passed through in the Ickleford boring at 75 feet, the 

 water in both cases being strongly impregnated with iron. This 

 bed appears to have a considerable lateral extension ; cottages close 

 to the Bedford road, as also the wells at Eamerick Farm, all take 

 their water from it. 



lY. Materials filling the Hitchin and Stevenage Gap. 



North or south of Hitchin but little information is to be obtained 

 of the nature of the superficial deposits which fill up the inequalities 

 of the old Chalk-surface of the Hitchin Valley below the 300-foot 

 contour-line ; but around the town are many gravel-pits where good 

 sections of the Drift can be seen. 



Wherever exposed, the Drift as a whole seems to consist chiefly of 

 flints and chalk-pebbles, with which is mixed a heterogeneous assem- 

 blage of rocks from the northward. Usually these materials are 

 distinctly stratified, but they vary in degrees of coarseness; and beds 

 containing, besides flints and chalk, big bonlders of Jurassic debris, 

 sandstone, limestone, and ironstone, pebbles of quartz, quartzite, and 

 red chalk, all more or less rolled, alternate with layers of finer gravel 

 or quartz-sand, the latter sometimes showing current-bedding. The 

 high dip and the frequently contorted aspect of the bedding seem to 

 indicate that these gravels were laid down by water under ' tumul- 

 tuous ' conditions. Boulder-Clay occurs closely associated with the 

 gravels, and between beds of gravel intervene not infrequently layers 

 of blue or grey clay containing ice-scratched stones. But there does 

 not seem to be any regular order of superposition, either in the 

 gravels themselves or in their relation to the Boulder-Clay. 



I may now give a brief description of t^he more interesting 

 sections of Drift to be seen near Hitchin. 



At the gravel-pit belonging to Messrs. Logsdon tfe Jackson, 



c2 



