TRE-DEVONIAN ROCKS 01-' THE MENDIPS AND THE BRISTOL AREA. 289 



Dowuhead quiirry, wliicli at a depth of 15 inches entered line-graiued 

 greenish ash, dipping 12-1;")° S.E., the dip being such as to indicate that, 

 as at Sunnyhill and probably Tadhill, fossiliferous ash underlies the trap 

 exposed further to the north. Fossils -were by no means so common as 

 at Tadhill, the only ones found being 



Rhynchanella DavidsnnI , M'Coy. 

 Orthis elegantula, Dalm. 

 Ptcrinea sp. 

 Calymene Blumenhacld, Brong. 



The most noteworthy points brought out by the work may be summarised 

 as follows : — 



1. Trenching proves that the coarse ashy conglomerate of Beacon 

 Hill extends to a point not far short of ^ mile to the east of the Butts. 



2. A band of tuff is found to be interbedded in the Moon's Hill 

 andesite. 



3. Sediments free from admixture with igneous matter occur close 

 below the outcrop of the Old Red sandstone, about \ mile N.E. of Long 

 Cross Bottom. These, though probably the newest Silurian rocks of the 

 district, contain a fauna of the same general type as elsewhere in the 

 inlier, i.e., probably of Upper Llandovery age. 



The Tortworth Inlier. 



Far more work has been devoted to the Tortworth inlier than to the 

 Eastern Mendip inlier ; but as the great majority of the facts ascertained 

 are recorded in a paper ' On the Fossiliferous Silurian Rocks of the 

 Southern Half of the Tortworth Inlier,' by Mr. F. R. Cowper Reed and 

 the Secretary, to appear in a forthcoming part of the ' Quarterly Journal 

 of the Geological Society,' they will not be repeated here. It may be 

 mentioned, however, that during the course of the work, which was 

 greatly facilitated by the kindness of the landowners. Lord Fitzhardinge, 

 Sir George Jenkinson, Bart., and especially Lord Ducie, eighteen old 

 quarries or exposures were opened up and about twenty-five trenches 

 were dug. 



The most important points with regard to the fossiliferous Silurian 

 rocks which have been ascertained or confirmed by the work are the 

 following : — 



o 



""& 



1. That the traps form two bands confined (with the possible ex- 

 ception of one small exposure) to the upper Llandovery rocks. 



2. That the base of the series is not seen, very little sedimentaiy 

 material being exposed below the lower trap band, and that the main 

 fossiliferous horizon of the Llandovery, which occurs between the two 

 trap bands, has a thickness of about 500 feet. 



:l. That the exposures of ashy limestone at Middlemill and Cullimore's 

 quarry, Charfield Green, which had previously been thought to rest 

 respectively on the lower and upper trap bands, are probably on the 

 same horizon and overlie the upper trap band. 



•1. That the highly fossiliferous calcareous sandstone of Daniel's Wood 

 also overlies the upper trap band, and is of approximately the same age 

 us the ashy limestones of ISliddlemiU and Charfield Green. 



n. That a small area of Llandovery rocks occurs in Eastwood Park, 

 and includes an exposure of the same highly fossiliferous calcareous 

 bandBtone as occurs in Daniel's Wood. 



1908. Tt 



