1821.] Red Rock Marie, or Neicer Red Sandstone. 255; 



detail may, perhaps, be thought too minute, but it would, I con-: 

 fess, be my own wish, had I the power and opportunity to render 

 them yet more so. It is even at this day only by the dihgent 

 accumulation of facts (and not unfrequently of those which may 

 seem at first the most insulated and insignificant) that we can 

 hope to obtain materials for the accurate history of the globe 

 which we inhabit. Believe me, my dear Sir, 



Yours, with much esteem, 



J. J. CONYBEARE. 



The series of strata distinguished by geologists as the red 

 rock marie, or newer red sandstone, occupies, as is well known, 

 a considerable tract in the county of Devon. Its geological 

 character and relations have been noticed by Deluc and others, 

 and more than one opinion has been given as to the nature and 

 origin of its contents, which, with a most sincere respect for 

 those from whom they have proceeded, I can scarcely regard as 

 compatible with the results of a dihgent, though, perhaps, a too 

 partial examination. A short residence at Dawlish afforded me 

 the opportunity, as well of observing the various aspects of the 

 rock itself, which, on that part of the coast, offers large and 

 uninterrupted sections, as of forming a tolerably complete series 

 of the different substances imbedded in the strata which extend 

 from thence to Teignmouth. 



In these strata the rock exhibits itself under the several cha- 

 racters of a sandstone, either loosely compacted, or altogether 

 pulverulent ; a marie, more or less indurated ; and a breccia 

 composed of fragments of various sizes. Near to Dawlish, the 

 sandy form is more frequent, towards Teignmouth the breccia, 

 thebase of which is usually marie, of an unctuous and argillaceous 

 character. The marie has frequently those patches of white and 

 purple, which have been often noticed as characteristic. The 

 mineral contents of the rock seem to be few. Calcareous spar 

 occurs in small patches a Httle south of Dawlish. Gypsum I 

 could not detect either here or under the elevated plains of 

 Haldon. On Blackdown, however, I have found it in small 

 nodules, A sand sufficiently charged with, and indurated by 

 iron, to be termed ironstone, traverses in all directions, the cliff 

 to the north of Dawlish (see Deluc, vol. ii. p. 85), and the earthy 

 brown oxide of manganese is found in numerous small cavities 

 nearly through the whole range of the coast. In one instance I 

 detected a small portion of the black oxide of cobalt, precisely 

 resembhng that found at Alderley edge (Cheshire) in the same 

 strata.* But the most remarkable feature in the rock appears to 



* I am indebted to the Rev. the Dean of Bristol for an addition to this meagre cata- 

 logue. That gentleman has had the kindness to forward me some specimens of chalce- 

 dony, which he discovered in this rock not far from Torquay. It is coarse, and appears 

 under the form of spherical nodules either hollow or investing portions of the marie itself 



