Vol. 63.^ ORIGIN OF THE PLATEAUS AROUND TORQUAY. Ill 



Babbacombe and Plainmoor to the foot of Warberry Hill. This 

 plateau is continued over Walls Hill, the highest part of which is 

 marked as 267 feet, and through "Wellswood, where, however, it 

 has suffered much from detrition, and does not rise above 254 feet. 

 Farther south is the limestone-hill of Stoodley Knowl, which is 

 only separated from Walls Hill by the depression of Anstey's Cove, 

 and reaches the same height. South-eastward is Black Head, 

 which rises to 304 feet, and may possibly have been part of the 

 plateau. 



South of the Ye ad own-Dais on plateau, the old plain has prac- 

 tically been destroyed by the long-continued action of rain and 

 running water, acting on a tract consisting of a broken and faulted 

 complex of Devonian limestones, slates, and grits. As a con- 

 sequence, this tract has been carved into a series of hills, ridges, 

 and spurs, none of which rise to the level of 250 feet. The highest 

 and most northerly eminences are Stantaways Hill (248 feet) and 

 Upton Hill (about 212 feet). Torre Hill does not rise above 180 

 feet, but Waldon Hill reaches about 200 feet ; while on Stentiford 

 Hill the ground rises to about 230 feet, and merges into the foot 

 of the Warberry ridge. Still farther south, Yane Hill and Daddy- 

 Hole Plain rise to a little above 200 feet. 



These hills and plateaus are so nearly of the same height 

 that one can hardly doubt that they were carved out of a southerly 

 extension of the ancient plain, though their summits are all now 

 very much below the level at which it must have passed, unlees 

 this portion of it has been let down by still later faulting. 



Age of the Plateau-Surface. 



The period of time within which this ancient plain must have 

 been formed is indicated within certain limits by the geological 

 structure and physical features of the district. 



In the first place, we have positive evidence of the post-Permian 

 age of the planation, in the fact that the Permian rock enters into 

 the structure of the plateau at St. Marychurch, where a tract of 

 Permian conglomerate lies between two parallel faults (see map, 

 fig. 1, p. 108 & section, fig. 4, p. 110), across which the surface of 

 the plateau passes without any interruption. In this tract the 

 conglomerate, or the surface upon which it rests, has a considerable 

 slope towards the east, for on the west side of St. Marychurch its 

 base rests upon Devonian limestone at a level of about 300 feet 

 above the sea, while on the coast at Oddicombe Beach it descends 

 below the level of the sea. The slope thus indicated may be a 

 pre-Permian slope, and not due to any subsequent tilting, for in 

 Oddicombe Cliffs the prevalent dip of the beds appears to be northerly 

 or north-easterly. In either case, the present surface of the ground 

 is due to subsequent planation ; and this surface merges into that 

 of the Babbacombe plateau, which consists of Devonian slates and 

 limestones. 



