488 



GEOLOGY OF THE SOUTH EAST OF DORSETSHIRE. 



rising in the centre, but trough-like on each side, marks the 

 space between the two formations. 



The appearance of this district from the coast is shown in 

 fig. 65, and the transverse section across the diluvial hollow 

 is given in fig. 66. It is premature to allude to the connec- 



BallardDown. Three-forked Down. Nine Barrow Down. Studland Heath. 



t I / 



J^»" ToSludland. 



Valley between the Chalk and Plastic Clay, — between Studland and Ballard Down. 



1, Chalk. 



2, Plastic clay. 



tion between the diluvial and the uplifting forces, but it may 

 be here safely mentioned, that the very aspect of the district 

 about Studland, from the summit of Ballard Down, and from 

 various stations in the ascent thither, demonstrably convince 

 the observer, that though violent denuding forces have exca- 

 vated the deep valleys and hollows between the chalk and the 

 sea, these valleys and hollows, whether longitudinal or trans- 

 verse, owe their primary development to preceding causes, 

 that uplifted, split, and convulsed the lower beds of chalk, 

 and the superimposed tertiary deposits that now only exist in 

 part. 



And since we have seen in this investigation, that the lines 

 of direction in these dislocations coincide with the longitu- 

 dinal and transverse directions of the chalk elevation — and 

 these again with those of the sub-cretaceous formations, it 

 follows, that the derangements in the plastic clay of Studland 

 owe their existence to the very same phenomena as have, in 

 the same linear directions, produced such striking alterations 

 in the arrangement of the country beyond the area of the 

 chalk-field. 



Subsequent investigations will more fully explain the ex- 

 tent of these derangements, but sufficient has now been said 

 to illustrate the phenomena of the plastic clay, at its junc- 

 tion with the chalk at Studland Bay ; — all of which are, evi- 



