EOCENE PERIOD. [Ch.XXII. 



bury, in Berkshire, is about five miles long and two in breadth. 

 The upper and lower chalk, as will be seen in the accompany- 

 ing section *, and the upper green-sand dip in opposite direc- 

 tions from an anticlinal axis which passes through the middle 

 of the valley along the line o, b, of the ground-plan (No. 78). 

 We subjoin an additional wood-cut, as conveying a scale of 



N. No. SO. S. 



Valley of Kingsclere. 



heights more nearly approaching to that of nature, although 

 the altitudes, in proportion to the horizontal extent, are even 

 in this, perhaps, somewhat in excess. On each side of the val- 

 ley we find escarpments of chalk, the strata of which dip in oppo- 

 site directions, in the northern escarpment to the north, and 

 in the southern to the south. At the eastern and western ex- 

 tremities of the valley, the two escarpments become confluent, 

 precisely in the same manner as do those of the North and 

 South Downs, at the eastern end of the Weald district, near 

 Pctersfieltl. And as, a few miles east of the town last men- 

 tioned (see Map, plate V.), the firestone, or upper green-sand, 

 is laid open in the sharp angle between the escarpment of the 

 Alton Hills and the western termination of the South Downs f ; 

 so in the valley of Kingsclerc the same formation is seen to 

 crop out from beneath the chalk. 



The reader might imagine, on regarding Dr. Auckland's 

 section (No. 7!)), where, for the sake of elucidating the geo- 

 logical phenomena, the heights are greatly exaggerated in pro- 

 portion to the horizontal extent, that the solution of conti- 

 nuity of the strata bounding the valley of Kingsclere had been 

 simply due to elevation and fracture, unassisted by aqueous 

 causes; but by reference to the true scale (No. 80), it will 



* Copied by permission from Dr. Bucklaml's plate XVII., Gcol. Trans., 2nd 

 Series, vol. ii. 



j- See Mr. Murchison's map, plate XIV., ibid. 



