﻿450 Horace B. Woodward — Notes on the Devonian Rocks. 



little to the west of north. We may trace the slates above them at 

 Cockingtou village, and if we proceed up the valley by Stanton, we 

 come upon the limestone dipping at from 20° to 24° a little to the 

 west of north. At the bottom of the valley immediately to the east 

 of Barton, thin flaggy red sandstones may likewise be traced beneath 

 the slates. 



In 1875 a well-section was made by the Diamond Eock Boring 

 Company's process for the Torquay Brewing and Trading Company 

 in Fleet Street, Torquay. The following details were kindly com- 

 municated to me by Mr. T. Perry, B.A., and although the boring 

 was not carried sufficiently deep to supply all the requirements of 

 the geologist, the facts are nevertheless of sufficient interest to be 

 noted. They are as follows : — 



Petitor Marble about 92 feet 



Plain Limestone ,, 247 ,, 8 incbes. 



(Hiatus of two or tbree feet filled witb soft 

 tenacious red clay.) 



Blue Slate , „ 82 „ 9 „ 



Chocolate Slate ,, 65 „ 7 ,, 



Blue Slate ,, 98 „ ,, 



Indurated Eed Marl ,, 42 ,, 7 ,, 



Depth of boring 628 ft. 7 in. 



The inclination (or '' natural cleavage " as it was termed) of the 

 limestones was about 70°, whereas the inclination of the slates was 

 no more than 45° ; and this difference I am inclined to think is due 

 to a fault between the two which runs north-west and south-east 

 along the margin of the limestone that extends from Torquay 

 Harbour to Daddy Hole. 



Owing to this inclination, the thickness of the beds passed through 

 may be estimated as follows : — 



Limestone 130 feet 



Slates 185 „ 



Red Marl 25 „ 



Concerning the so-called " Indurated Eed Marl," I saw a specimen 

 which seemed to belong to one of the junction beds between the 

 slates and red sandstones, but it would be hazardous to express any 

 more definite opinion about it. 



The succession of limestones, slates, and red sandstones here 

 pointed out is not new : the results of my own field-work rather 

 coincide with the views expressed fifty years ago by De la Beche. 

 Nevertheless, a different interpretation was put upon the structure 

 of South Devon by Dr. Holl ; and De la Beche himself was led in 

 after years to modify his opinions concerning the classification of the 

 beds, so as to conform with the views of Sedgwick and Murchison. 

 It was in 1827 that he gave an account of the geology of Tor and 

 Babbacombe Bays. The limestones he then termed Carboniferous 

 Limestone, stating that the beds " contain fossils that have been dis- 

 covered in the Carboniferous Limestone of other places, and, though 

 a matter of minor importance, mineralogically resemble it; they are, 

 moreover, separated from the Old Eed Sandstone by a shale, which 

 may be considered the equivalent of the Lower Limestone Shale." ' 

 1 Trans. Geol. Soc. 2nd str. vol. iii. p. 163. 



