﻿Vol. 6l.] CONTIGUOUS DEPOSITS OF GLAMORGANSHIRE. 397 



are found to have changed, both as regards faunal and lithic 

 characters : — 



Thickness in feet inches. 



Shales, black, clayey seen 2 



( a. Limestone and quartz-sand 4 Gyrolepis Alherti ; 



Ostrea (?) 



b. Limestone, earthy 3 



c. Clay 1 



d. Limestone, irregular masses: to 9 

 inches 5 Gyrolepis Alherti. 



\ e. Marl, black and brown 6 



5 | f. Limestone, hard, crystalline in the 

 upper portion : the lower simulates 



Carboniferous Limestone 7 Fishes (scales and 



\g. Marl, hard, shaly seen 10 teeth). 



In a road-cutting between Merch and Cogan Hall certain Rhsetic 

 beds are exposed, including a bone-bed : — 



Thickness in feet inches. 

 10 to 14 ? Shale, black, clayey : possibly about 4 5 [lepis. 



15. Limestone, hard, grey : to 2 inches 1 Schizodus (?) ; Gyro- 



16. S b a] e, black, clayey 6 f iSatirichthysacumina- 



17. Arenaceous rust-coloured deposit ... 1 -4 tus, Gyrolepis Alber- 

 18 to 21. Shale, black estimated at 3 [ ti; quartz-pebbles. 



It is impossible to correlate these beds with certainty, and so 

 the numbers affixed to them must be regarded merely as suggestive. 



About halfway between the foregoing section and the place where 

 this lane joins the Cogan road, fish-remains are not uncommon in 

 the Sully Marls. Although these beds are well-developed in this 

 outlier, it is recorded in the Geological-Survey Memoir that, whereas 

 a certain zone occurs 26 1 feet below the Elastic Black Shales at 

 Lavernock, in this outlier it occurs only 14 feet below that datum- 

 level. 1 This may point to some overlap of the Sully Beds (see 

 p. 413). 



ii. Barry to Cowbridge. 



In the district between Barry and Cowbridge there are three 

 important sections of the beds under consideration, namely, at 

 Barry (Coldknap), Cadoxton, and Tregyff (near Cowbridge). 



Two small outliers of Bhaetic Beds occur on Barry Island. The 

 northernmost patch has been investigated by Mr. F. T. Howard, F.G.S., 

 who has recorded a number of fossils. 2 



(A) Coldknap, Barry. 



In the low cliff near Coldknap Farm, and facing Barry Island, 

 is a section of much interest and importance. In the Geological- 

 Survey Memoir on the Cardiff district it is recorded that 

 ' Rhaetic shales are exposed again as an inlier near Coldknap. They form a 



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

 Country around Cardiff' Mem. Geol. Surv. 1902, p. 54. 



2 Trans. Cardiff Nat. Soc. vol. xxvii (1891-95) p. 42. 



