26 L. RicJtardson — Rhcatic Rocks of WarmcksJiire. 



(1) Marl Cliff. 



(2) Half a mile north of Billesley. 



(3) A mile and a half 3^ S. of W. of Bearley Jmiction. 



(4) Near Whitehall Farm. 



(5) At Atherstone Hill, near Preston-on-Stour. 



(6) AtLoxley. 



(7) At Red Hill, to the north of Ettington Station. 



(8) At Chesterton Green, near Harbury. 



II. Subdivisions of the RniETic Eocks eecognizable in 

 Warwickshire. 



Black Shales or Westbcry Beds. — There is now no good exposure 

 of these Black Shales in the county; but a number of sections have 

 been available from time to time when the railways were in course of 

 construction. 



From what lias been recorded and from specimens that have been 

 obtained, especially from Summer Hill, it is obvious that at certain 

 horizons they are extremely rich in fossils, particulaily in specimens 

 of Fteria contorta and in species belonging to the genus Isocyprina. 

 Hard beds do not seem to be prominently developed ; but a number of 

 thin sandstone-layers are reported to occur in the lower portion of the 

 Black Shales in the Summer-Hill railway-cutting ; while Brodie 

 obtained numerous masses of highly -fossiliferous Pi?e^^M-Limestone 

 from temporary excavations at Brown's Wood, which is situated 

 3J miles to the west of Bearley Junction. The Bone-Bed, as a 

 stratum rich in vertebrate-remains, appears to be very poorly 

 developed. The only record of it, apparently in its typical condition, 

 is one by Strickland, who observed it, in situ it is said, somewhere in 

 the neighbourhood of Bidford.^ In what is probably its usual condition 

 in Warwickshire, namely, a yellow micaceous sandstone, it has been 

 observed at Ivnowle and in the railway-cutting near Kineton. 



It has not been possible, owing to lack of sections, to determine 

 the precise thickness of the Black Shales. At Dunhampstead, in 

 Worcestershire, they are about 18 ft. 6 in. thick, and at Wigston, near 

 Leicester, 29 ft. 9 in. In Warwickshire it is to be presumed that 

 their thickness lies between these figures, and in my opinion there is 

 no reason for believing that they are absent from anywhere — not even 

 from the Church Lawford neighbourhood. 



The sharp line of demarcation between the Black Shales and Tea- 

 green Marls is ipso facto suggestive of a non- sequence, and at Snitter- 

 tield, near Stratford, Brodie, as long ago as 1 886, thought he had 

 evidence that indicated that the Tea-green Marls had been subjected 

 to erosion previous to the deposition of the Black Shales. Be this as 

 it may, the lower limit of the Black Shales in Warwickshire is every- 

 where, as far as we know, 'sharply-defined.' 



This, however, is not the case with regard to the upper limit of the 

 Black Shales, for they merge into the greenish-grey marls of the Upper 

 Rhsetic. 



Gotham Beds. — These deposits are almost wholly marl of the usual 

 greenish-grey tint, and are continuous throughout the county. K^o 

 stratum exhibiting Gotham-Marble facies has been detected; but the 



1- Q.J.G.S., vol. xxi, p. 160, 1865. 



