394 



GEOLOGY OF THE SOUTH EAST OF DORSETSHIRE. 



by cracks which have traversed them as well as the chalk ; 

 and the beds of chalk are compressed into extremely thin la- 

 mina, the edges being turned up against the portions that yet 

 retain their horizontality of position, as if, after the upheav- 

 ing, they had again fallen back, which was also the case, as 

 I endeavoured to show, in the Ballard Head fault. At I, in 

 fig. 47, the situation of three faults is shown. The first is in- 

 dicated by a vertical crack down the cliff', on each side of 

 which the beds of flint are curved, first dipping to the fault, 

 and then rising in a curvilinear course at a higher elevation, 

 as shown in figure 48. A few paces to the eastward the thick 

 blocks of chalk are succeeded by a mass of about two feet 

 wide, consisting of lamina from \ to ^ an inch thick, gradu- 

 ally passing into larger blocks as before, but dipping 11° to 

 N.W. : ten paces further a similar laminated mass, dipping 

 to the S.E. occurs, so as to mark the eastern limit of the de- 

 ranged mass. The beds are here all strongly marked by yel- 

 low seams, and the fault and strata divisions are coated with 

 yellow matter, — the flints are also much displaced and shat- 

 tered. But the most extraordinary appearance is, that the 

 thinly laminated bed appears to mark an internal derange- 

 ment in the cliff", for about six feet from the first fault, the face 

 of the cliff is protected by a continuation of larger beds and 

 blocks, through an opening in which the smaller lamina are 

 seen, and, on inspection, this face is separated from the por- 

 tion behind by a line of fissure which slopes in a slanting di- 



Faults in the chalk cliffs, Studland Bay. 



A a, vertical fault. B b, line of fault. C, b, D, thin laminee of chalk. E, opening 



in the face of the cliff, through which thin lamina, are seen. 1, 2, lines of flint. 



At C the flints are fractured and the chalk yellow,— the edge of the fault striated and rubbed. 



