494 PLEISTOCENE. 



from the spots where they originally were formed. The flints from the Chalk also 

 are sometimes rolled and transported to positions where they could not have been 

 worked out in situ. Mingled with these accumulations we find near Yarcombe and 

 other places between Honiton and Chard many quartz pebbles, and pebbles of hard 

 quartzose grit and quartzite which are evidently foreign to the immediate neighbour- 

 hood. Looking at these deposits in a large way, it seems that they may be partly 

 due to the subaerial denudation of the Chalk and Greensand ; and if the foreign 

 pebbles be not relics of Tertiary deposits, they may have been introduced during 

 the Glacial period. ^ Near Tiverton also there are considerable accumulations of 

 gravel which may be of Glacial age.* 



The Gravels and Sands bordering the Bovey Basin near Newton Abbot seem to 

 be connected with the Drifts which cap the Haldon and Blackdown Hills. They 

 appear to have been deposited in this Basin, and perhaps to have filled it, when 

 many of the neighbouring valleys had not been excavated.^ (See Fig. 30, p. 194.) 

 The deposits consist of coarse gravel and sand with seams of clay ; and the stones 

 include large blocks and pebbles of grit, quartz, flint and chert. They have 

 been well exposed at Woolborough and Milber Down. The occurrence of Bctiila 

 tiaiia and Salix cincrca, in a superficial deposit at Bovey Heathfield, has been 

 noted by Mr. Pengelly."' The same geologist has also described some scratched 

 stones found at Englebourne, and some boulders of hard micaceous sandstone 

 met with at Waddeton near Dartmouth in South Devon, which are suggestive of 

 Glacial action, although the boulders are of local origin. The same is the case in 

 North Devon, at Saunton and other places where boulders have been observed. 



Fig. 85.— Section of Cliffs at Godrevy, Cornwall. (W. A. E. Ussher.) 

 Vertical scale i inch to 24 feet. 



Head. 



;■ Raised Beach. 



Slate. 



Cave. 



A deposit of brown potter's clay, at Fremington and Roundswell, south-west of 

 Barnstaple, has been considered as possibly of Glacial age ; it is in places 40 feet 

 thick, and contains boulders of igneous rocks. ^ 



Many years ago, in describing the disturbances or ' Terminal curvature ' of the 

 slate in South Devon, Mr. Godwin-Austen observed that though it would be 

 hazardous to say that these appearances may not have resulted from the long-con- 

 tinued action of actual frosts, yet when we consider the great extent to which this 

 separation of the leaves of the slate has been carried, and the very inconsiderable 

 depth to which frost at present penetrates in this part of England, we seem to 

 require a period with a lower temperature and the action of deeper searching cold.^ 



1 G. Mag. 1S74, p. 335 ; W. A. E. Ussher, Q. J. xxxiv. 51 ; Buckland, T. G. S. 

 (2). i. 101, ii. 127 ; Buckland and De la Beche, T. G. S. (2), iv. 7 ; Godwin- 

 Austen, Q. J. vi. 91, xiii. 45. 



2 G. Mag. 1872, p. 574. 



^ Q. J. xxxii. 230 ; see also De la Beche, Geol. Manual, 1831, pp. 157, 190 ; 

 J. A. Birds, G. Mag. 1878, p. I13 ; T. Belt, Q.J. xxxii. 80. 



* Trans. Devon Assoc, xv. 368, vii. 154, ix. 177, xii. 304; see also G. W. 

 Ormerod, G. Mag. 1869, p. 40 ; G. Maw, Q J. xx. 451. 



s G. Maw, Q. J. XX. 445 ; G. Mag. 1865, p. 526 ; Ussher, Q. J. xxxiv. 450. 



^ T. G. S. (2), vi. 433 ; see also De la Beche, Geol. Manual, p. 41. 



