﻿Vol. 6 1.] CONTIGUOUS DEPOSITS OF GLAMORGANSHIRE. 407 



(B) Quarella Quarry, Bridgend. 



North of Bridgend are the well-known Quarella Quarries, where 

 pale-green and white lihgetic sandstones are worked, the rock being 

 very suitable for building-purposes. A single block from Bed c (of 

 the sandstone-deposit) of the appended record measured 72 x 53 X 44 

 inches, and must have weighed about a ton and a half. The deeper 

 quarry, and that which yields the more satisfactory section, is 

 situated on the south side of the lane : — 



OSTJREA 



Beds. 



Oh 



Thickness in feet inches. 



Limestone, grey 6 



Shale-parting 1 



Limestone 3 



Shales, bluish-grey and brown . .. 4 



( 1. Shales, hard, passing into hard bluish-grey limestones 



with conchoidal fracture maximum 7 



a. Shale, black and brown, clayey 4 



b. Shale, hard 4 



,_c. Marls, greenish and yellowish 1 8 



^ | ■{ 3. Limestone, argillaceous, nodular: 3 to 5 inches 4 



4. Green and yellow sandy marls ; almost a fine sand- 

 stone in places , about 6 6 



I fa. Sandstone, pale-green and white, rather broken up... 4 4 



j r \ b. Sandstone 3 4 



l^' c. Sandstone 4 



i z,(9\ 1 ^- Sandstone 4 



' ^'' j c. Sandstone, more flaggy, and therefore in thinner layers, 



^ seen 8 6 



The first notice of this section is contained in Tawney's paper 

 * On the Western Limit of the Rhsetic Beds in South Wales & on the 

 Position of the " Sutton Stone.'* ' He regarded the sandstone-beds 

 as belonging to the "Keuper, while * 6 feet of green sandy marls ' 

 he doubtfully referred to the Bliaetic. 1 Charles Moore observed 

 (Quart. Journ. Geol. Soc. vol. xxiii, 1867, p. 513) that 



' in the valley west [north ?] of Bridgend the Keuper Sandstones are largely 

 worked, but their succession upwards into the Lias is not well exposed.' 



H. W. Bristow, however, corrected this error (ibid. p. 205) : 



' the sandstones quarried for building and grindstones .... are not situated 

 at the base of the Keuper, as stated by Mr. Tawney, but are in the upper part 

 of the Bbastic Series, overlain by Lias crowded with the characteristic Ostrea 



Whichever subdivisions of the Rhaetic are represented here, and 

 in the absence of fossils (except for a Lima) it is difficult to decide, 

 it is obvious that we have the equivalents of nearly the whole 

 series. The stratum distinguished as 1 much resembles the Cotham- 

 Marble equivalent ; while the nodular limestone (3) is very sugges- 

 tive of the Estheria-Bed. From the limestones capping the section 

 Mr. Tiddeman obtained Ostrea liassica and Pleuromyar 



1 Quart. Journ. Geol. Soc. vol. xxii (1866) p. 72. 



2 ' Summary of Progress of the Geological Survey for 1899 ' (1900) p. 130 

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

 Country around Bridgend' Mem. Geol. Surv. 1904, p. 51. 



