﻿406 MR. L. RICHARDSON ON THE RHJETIC AND [Aug. IC)05 T 



Rhsetic beds are preserved between two faults, as recorded in the 

 Geological-Survey Memoir, but they have been omitted— no doubt 

 inadvertently — from my copy of the map. 



iii. Cowbridge to Pyle. 



At most localities between Cowbridge and Pyle the Black Shales 

 and intercalated sandstone-bands, which usually constitute the deposit 

 laid down during the contorta-&ge, are replaced by massive sandstones 

 containing few fossils ; while, during the time when the Upper 

 Btetic was deposited, a greenish marl with red streaks was formed. 



What details concerning the Khsetic can be obtained in the 

 neighbourhood of St. Mary Hill have been recorded by Mr. Tiddc- 

 man l ; it is, therefore, sufficient to state here that the arenaceous 

 element predominates over the argillaceous. 



The road between the railway near Coychurch and Coity runs 

 along the outcrop of the Rhsetic, of which there are several ex- 

 posures ; as, for instance, seven-tenths of a mile north-west by west 

 of Coychurch Church, and again in the road at Simondston. In the 

 village of Coity itself, sandstones and shales of a greenish tint (but 

 mottled red in places), and full of Modiola minima (?) Sow., are 

 seen in a road-cutting near the Castle. 



(A) Hendre, near Pencoed. 



Between Hendre and Pencoed the Rhsetie has been disturbed by 

 two faults, that on the north letting it down against clayey shales 

 belonging to the Millstone Grit. The Hendre brick-kilns are 

 situated on the Keuper Marls. At a slightly-higher level to the 

 north are -the Phoetic sandstones, faulted against the Millstone Grit. 

 A passage driven from the brickworks to the bottom of the clay- 

 pit passes through the Phastic sandstone, and from such fissile rock 

 numerous ill-defined casts, of a lamellibranch of Schizodus-isicies, 

 were obtained. The Keuper Marls are excellently exposed in a pit 

 adjoining the works. 



A little to the east of the Hendre brickworks are two quarries 

 in which massive Phsetic sandstone is worked. Pidlastra arenicoh 

 and scales and fragmentary bones of Gyrolepis Alberti have been 

 collected in this neighbourhood by Mr. Tiddeman, who has also 

 given the following record of the sequence of deposits 2 : — 



Thickness in feet. 

 Lower Bh^etic. Sandstone, white, fine-grained, massive below and more 



thinly-bedded and yellowish above seen 30 



fa. Sandy beds 3 



xt | b. Green and yellow marl 15 



Keuper ^ c ' -^ arc * mar l» with ' race ' and gypsum 2 



\ d. Clayey red marl 2 



\je. Clay and marl; proved in a well 30 



1 ' Summary of Progress of the Geological Survey for 1899' (1900) p. 129 and 

 ' The Geology of the South-Wales Coalfield : Pt. vi— The Geology of the 

 Country around Bridgend ' Mem. Geol. Surv. 1904, pp. 50, 51. 



2 ' Summary of Progress of the Geological Survey for 1899 ' (1900) p. 129 and 

 'The Geology of the South- Wales Coalfield: Pt. vi-The Geology of the 

 Country around Bridgend' Mem. Geol. Surv. 1904, p. 50. See also his 

 pamphlet on the ' Quarella Quarries,' Bridgend, 1893. 



