Vol. 55.] CONGLOMERATES OF THE LOWER SEVERN BASIN. 121 



Wenlock Edge, in Shropshire, yields only 0'31 percent, of magnesia. 

 Specimens more recently found in the Abberley Hall grounds are 

 apparently more magnesiferous than that from Woodbury Hill 

 which has been analysed. The specimens from !May Hill contain 

 28'3 per cent, of magnesia. 



These Abberley Hall dolomitic Wenlock Limestones (in place) 

 are nearest to the Bowhills district (8 miles), where pebbles of 

 similar dolomitic limestones occur in the Permian conglomerates in 

 great abundance (50 per cent.). On the other hand, the Abberley 

 Hills are 16 to 25 miles distant from the South Staffordshire region, 

 w^here the dolomitic limestones constitute less than 10 per cent, of the 

 pebbles found in the Permian conglomerates. 



(b) The ;N'on-dolomitic Limestones. — These are the ordi- 

 nary type of Wenlock Limestone, coarsely crystalline, grey, passing 

 through finely crystalline greyish-white to compact non-crystalline 

 types. Up to the present no satisfactory fossils have been found in 

 these, partly because the fragments are so small ; but lithologically 

 they are the same rock-types as the Wenlock Limestones now ex- 

 posed in the centre of the South Staffordshire Coalfield at Dudley. 

 These non-dolomitic limestones constitute from 20 to 30 per cent, 

 of the pebbles in the Stour Valley and Warley-Barr districts, while 

 in South-east Shropshire they are comparatively scarce. 



We are thus confronted with the striking fact that the dolomitic 

 Wenlock Limestone-pebbles in these Permian conglomerates prevail 

 in the South-east Shropshire region, and the non-dolomitic Wenlock 

 Limestones abound in the Stour Valley and Warley-Barr districts ; 

 and that, close to the aforesaid Shropshire region, dolomitic Wenlock 

 Limestones are in place, while in the Stour VaUey and Warley-Barr 

 districts the non-dolomitic Wenlock Limestones of Dudley are in 

 place. 



(7) DowNTON Sandstone occurs as a greenish coarse-grained rock, 

 in place, at Abberley. A pebble of the same type, containing un- 

 identifiable fossils, has been found in the calcareous conglomerates 

 of Bowhills, 8 miles to the north. 



(8) Passage-bed to Old Eed Sandstone. — At Abberley and Trimp- 

 ley a peculiar yellow claystone occurs in place, near the junction of 

 the Downton Sandstone and Old Red Sandstone ; and precisely the 

 same lithological type occurs in the conglomerates of the Bowhills 

 district, 8 miles north-west of Abberley and 2 miles north-west 

 of Trimpley. This is evidently the rock to which Mr. Gr. E. Roberts 

 aUuded in the same terms as I have done (see p. 98). 



(9) Old Red Sandstone. — This formation has a wide outcrop on the 

 Trimpley anticlinal, and is partly composed of a close, fine-grained, 

 evenly-bedded, purplish, hard and compact sandstone. Precisely 

 similar pebbles occur in the calcareous conglomerate of Warshill, 

 which is close to the edge of this anticlinal, and in the calcareous 

 conglomerate of Bowhills. I have not found Old Red Sandstone 

 anywhere else. This apparent absence of Old Red Sandstone 

 pebbles is consistent with the evidence obtained from two borings 



