﻿400 MR. L. RICHARDSON ON THE RHJETIC AND [Aug* 1905, 



Shales were more in evidence, and pieces of a Pecien-lAmestone 

 containing the characteristic lamellibranch, fragments of a Placun- 

 opsis, and fish-scales, were lying about. Still nearer Blackland 

 higher beds were exposed, including thin bands of pale limestone 

 intercalated in similarly-coloured shale, altogether 3 feet 4 inches 

 thick, and resting upon grey and yellow shale (belonging presumably 

 to the Upper lihsetic), of which a thickness of 6 inches was 

 visible. Where the a in Bedland comes on the 1-inch Geological- 

 Survey map there is a large quarry in the Carboniferous Limestone. 

 In one place some green marl has been washed down a fissure, but 

 on the whole, as noticed by Mr. Cantrill, 



the Rhastic soil can be recognized so close to the brow of a large quarry in 

 Carboniferous Limestone, as to suggest that the Keuper is here wholly over- 

 lapped, as shown on the map.' * 



A pond to the east of the ancient camp at Leige Castle is in the 

 Black Shales, and . from pieces of P^<??2-Limestone were obtained 

 Labyrinthodont-bones (small pieces), scales of Gi/rolepis, coprolites 

 (fish), and fragments of Pecten (Chlamys) valoniensis. A section 

 showing the junction of the Rhsetic and Carboniferous-Limestone 

 deposits can be studied in the roadside 200 yards north-west of 

 Ty'n-y-coed, but here — as at Eedland — the Rhaetic Beds exhibit no 

 littoral facies, such as might be at first expected. 



The finest section in the Cowbridge district is in a road-cutting 

 at TregyfF, near the St. Mary-Church Road Station on the Cow- 

 bridge & Aberthaw liailway. It is dealt with in the Geological- 

 Survey Memoir (ojy. cit. p. 40) in the following short passage : — 



' They [the E,ha;tic deposits] emerge south-east of Wren Castle, and here for 

 the first time exhibit signs of the oncoming of a more arenaceous type, in the 

 intercalation of bands of greenish-grey sandstone. These may be traced south- 

 wards along the valley, but are especially well-shown in a road-cutting at 

 TregyfF, though the beds undulate gently down the road westwards at such an 

 angle that only a few feet are exposed. They consist of sandstone with 

 Protocardium Phil ippiamim and Avicula contorta, blue sandy marls, a thin 

 conglomeratic band containing pebbles of Carboniferous Limestone and cliert 

 and black limestone with Pecten valoniensis? 



(C) Tregyff, near Cowbridge. 



Thickness infect inches. 

 Limestone, pieces not in situ. 

 Shales, brown (several feet). 



Limestone, dark 1 



Shales, brown 1 3 



( ^Shales, black, with several bluish 



gritty layers 1 



Limestone, brown and blue 1£ 



Shale, weathering brown 



Sandstone, fine-grained, calcareous 1 Casts of worm-burrows 



ba \ Shale, black, weathering brown ... 7 [on the underside. 



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

 Country around Bridgend' Mem. Geol. Surv. 1904, p. 39, 



