﻿Vol. 6 1.] CONTIGUOUS DEPOSITS OF GLAMOKGANSHIRE. 399 



The most interesting exposure in this neighbourhood is in the 

 sides of a field-road, near the brook, about three-fifths of a mile in 

 a direction a little to the south of west of Cadoxton Church. 



(B) Cadoxton. 



Thickness in feet inches. 



a. Marls, yellow and black 



( Lepidotus (?) , Acrodus 



b. Limestone, hard, dark, in masses minimus, Gyrolepis 

 t mixed with dark -brown clay: Alberty bone (Laby- 



| 3 to 9 inches 6 rinthodon 1 ') ; Ostrea 



P-l j Bristovi (see PI. 



g j XXXIII, fig. 4), 



^ j Pteria (Avicula) (?) 



go \ c. Shales, black, earthy 1 8{ contorta ; Natica (? ) 



| d. Limestone, hard, dark 6 Ostrea Bristovi (rare). 



I e. Shales, black and brown, with yellow 



1^ streaks. 



The necessity for grouping the Sully Beds with the Ehaatic will 

 be obvious from the foregoing section, although it should be men- 

 tioned that the fossils are not individually numerous. Here it will 

 be noticed that Ostrea Bristovi is associated with Pteria (Avicula) 

 contorta and other Ehsetic lamellibranchs. 



Pteria ( Avicula ) - contorta Black Shales, with an extremely 

 fossiliferous Pecten-Bed, are to be seen in the deeply-cut lane three- 

 fourths of a mile north by east of Cadoxton Church : the limestone- 

 bed yields Pecten valoniensis, Pteria (Avicula) contorta, Schizoclus 

 Ewaldi, and a Placunopsis similar to that which occurs in Bed 1 of 

 the Eedland (Bristol) section. 1 



Between the last section and Eedland (near Bonvilston) the 

 Ehsetic deposits are but seldom exposed. Black shales with thin 

 P^cten-Limestones have been observed in a brook on the north side 

 of Bears Wood, south of Wenvoe Castle, and again west of 

 St. Nicholas, ' on both sides of the valley and in Coed-y-Cwm.' 2 



In a road-section at Eedland (Sheets 261, 262) some interesting 

 details can be observed. In the Geological-Survey Memoir on the 

 country around Bridgend is the following passage : — 



'A small quarry 100 yards south of Eedland shows the Avicida-contorta Shales 

 overlying a hard yellow dolomitic rock of Tea-Green Marl age, while Carbon- 

 iferous Limestone, apparently in place, crops out on the opposite side of the 

 road. Here, then, we can fix a point on the Keuper coast-line, for the lime- 

 stone-ground to the north was still above water at the close of the Keuper- 

 Marl period.' ('Geology of the South-Wales Coalfield : Pt. vi' 1904, p. 30.) 



In August 1904, the section on the west side of the road exposed 

 a boss of Carboniferous Limestone wrapped round, by Black Shales. 

 This boss, at the road-level, measured 2| feet across, and stood 2 feet 

 high. A little farther in the direction of Blackland the Black 



1 A. Eendle Short, Quart. Journ. Geol. Soc. vol. lx (1904) p. 171. 



2 ' The Geology of the South- Wales Coalfield ; Pt. iii ' Mem. Geol Surv 

 1902, p. 65, 



