﻿454 Clement Reid — Culm-meamres near ChucUeigh. 



So far as one can judge at present, tlie evidence certainly favours 

 the views of Jukes, that the basement beds of the Devonian system 

 are truly Old Eed Sandstone, v^^hile the succeeding slates and lime- 

 stones were formed during what we call the Lower Carboniferous 

 period, and in a different zoological province to the Mountain Lime- 

 stone of other parts. The view that the entire series of the Devonian 

 rocks was deposited during the same period as the Old Eed 

 Sandstone is entirely unsujDported by physical or stratigraphical 

 evidence, for it requires a barrier to have existed at the time, 

 separating a lacustrine from a purely mai'ine area, and of this we 

 have not the slightest evidence. And indeed, just where we should 

 look to find it, we come across the mass of Limestone at Cannington 

 Park, which some observers call Carboniferous Limestone and some 

 Devonian Limestone. Perhaps both views may be right. 



VIL — On the Junction of the Limestone and Culm-measures 



NEAR ChUDLEIGH. 



By Clement Eeid, F.G.S., 

 of the Geological Siu-vey of England and "Wales. 



(Communicated by permission of the Director-General of the Geological Survey of 

 the United Kingdom.) 



IN the course of an examination of the district around Chudleigh 

 during the year 1875, I was led to consider that there is a 

 passage from the Devonian Limestone into the Culm-measures, and 

 that all the appearances which have been accepted as indicating un- 

 conformability may be easily accounted for hy a fault with a con- 

 siderable hade. 



The peculiar position of the Chudleigh Limestone has led to many 

 hypotheses in explanation of the manner in which it appears to abut 

 against the Culm-measures. Sir Henry De la Beche, judging from 

 the apparent dip of the Culm-measures beneath the Devonian rocks, 

 considered that the Limestone was included in the Carbonaceous 

 Series, and as such it was engraved in his published sections and 

 coloured in the Geological Survey Map. 



Mr. Godwin-Austen and most subsequent writers have recog- 

 nized the identity of the limestone of Chudleigh with that of Newton 

 Abbot, but have considered that there is evidence of unconform- 

 ability, and have drawn hypothetical sections in support of this view. 



The following fossils, which I collected from the limestone in the 

 neighbourhood of Chudleigh, correspond closely with those to be 

 found near Newton Abbot. The species have been identified bj' Mr. 

 Etheridge : — 



Lower Dunscombe Quarry (upper part of the limestone) : 



Rhynehonella pug nils, Mart. sp. 



,, cuboides, Sby. 



Atrypa, sp. 



5, reticularis, Linn. sp. 

 Kerswell Quarry (middle or lower part of the limestone) : 



Streptoyhynchus crenistria, Phil. 



Fenestella. 



Cyrtoceras. 



Stromat.opora. 



Oyathophyllum emspUosum, Goldf. 



Fmosites cervicornis, Edw. 



Hcliolites ijorosa, Goldf. 

 Alveolites suhorhicidaris, Lamh. 

 Fullastra. 



