OF THE DEVON COAST-SECTIOIf. , 76 



by Dr. Credner^ of the Eothliegendes. Dr. Credner emphasizes the 

 presence of such hard interbedded shales as indicating Eothliegendes 

 character and age. His words are : — " Die Schieferletten oder 

 Eothelschiefer, ein hint- bis braunlichrother, sehr eisenoxydreicher 

 Schieferthon ( = shale), ist ein f iir das Eothliegende c/anz besonders 

 charaJcteristisches Gestein und tritt in oft machtigen Zwischenlager- 

 ungen zwischen den Konglomeraten und Sandsteinen auf ." ^ 



The fact, moreover, that some of the sandstones have a Bunter 

 fades is paralleled in other parts of England. Thus Mr. Pox- 

 Strangways speaks of the so-called ' Middle Marl ' (between the 

 Upper and Lower Magnesian Limestone) as consisting of "red marls 

 and soft red sandstone, which in some sections is excessively like 

 that of Triassic age." ^ But the position of these beds in relation to 

 the limestones leaves no doubt as to their Permian age. Purther. 

 there seems to be a close resemblance between the sandstones inter- 

 stratified with the Lower Marls of Devon and the 1500 feet of soft 

 red or variegated sandstones of Colly hurst -and Stockport, described 

 by the late Mr. Binney in various jDapers read at Manchester in the 

 years 1841 to 1862. On the other hand the occurrence of hundreds 

 of feet of purple-red marl of a distinctly Permian t3'^pe below the great 

 Pebble-bed in Devon would be (though a normal Permian feature) an 

 altogether abnormal feature of the Lower Bunter, as compared with 

 the uniform development of sandstones of that division in the Mid- 

 land cou^nties and in the Severn country.^ 



In his paper ' On the Chronological Value of the Triassic Strata 

 of the South-western Counties ' ' Mr. Pssher points out (p. 466) that 

 of the 850 feet, which he assigns to the sandstones and marls 

 between the breccia-series and the great Pebble-bed, the lower 

 portion " may be regarded as a passage-series [from the marls, 

 which he estimates at 500 feet] into the lowest division " [the 

 breccias]. He also states (loc. cit.) that he " traced, between Thorn 

 St. Margaret and Wiveliscombe, in very clear sections, a downward 

 passage from the Lower Maris through an intercalated series of marls 

 and clays with beds of saud, the latter predominating downwards, 

 into the sandstones generally representing the basement-beds in that 

 neighbourhood.'" Another remark of Mr. Ussher {loc. cit.) that " in 

 their northerly extension these beds gradually attenuate ; and they 

 [the 850 feet of sandstones and marls] do not probabl}^ exceed 200 

 feet, taken together, to the north of Thorn St. Margaret," gives, I 

 think, strong support to the evidence of the unconformity at the 

 base of the great Pebble-bed for which I contended in my former 

 paper. Prof. Hull *^ describes a similar instance of the attenuation 

 of the Permian Series in the Severn country, from 1500 feet of 



1 ' Elemente der Geologie,' 6th ed. (1887) pp. 509-511. 



2 Ibid. p. 510. 



•^ Mem. Geol. Surv. (1873) ' Geology of the Country North and East of Har- 

 rogate,' p. 11. 



^ See Hull, Mem. Geol. Surv. (1869) ' Triassic and Permian Eocks of the 

 Midland Counties,' chap. v. pp. 32-44. 



•^ Quart. Journ. Geol. Soc. vol. xxxiv. (1878) pp. 459 et seq. 



^ ' Triassic and Permian Rocks,' &c. p. 32. 



