36 Murchisoris Silurian System. 



there surmounted by the calcareous conglomerate or central 

 and upper strata of the New Red System. At whatever 

 point we fix the limit between the overlying sandstones and 

 the coal measures, it must be borne in mind, that the only 

 carboniferous strata into which these beds graduate in this 

 immediate neighbourhood, constitute the poor and slightly 

 productive end of the Dudley field, and that speculations in 

 search of coal seams, by sinking to great depths beneath the 

 Lower New Red in this tract would be quite ruinous, 

 since we know that the mineral thins out to mere shreds 

 in its course to the south : further explanations of this 

 point will be given in the account of the Dudley coal- 

 field. In following the margin of the great Stafford- 

 shire coal-field, we invariably find that wherever gravel 

 and superficial detritus does not obscure the relations 

 of the strata, a zone of red sandstones, of considerable 

 thickness, is interposed between the coal and the calcareous 

 conglomerate. At the Stand Hills it is a hard, greyish, 

 partially reddish, and slightly calcareous sandstone, with a 

 few blotches of yellowish marl, and some veins of white car- 

 bonate of lime, passing upwards into a pebbly, deep red, 

 soft sandstone. At the straits between Himley and Turner's 

 Hill, it is a thick-bedded, deep red, soft sandstone, in parts 

 slightly calcareous, full of irregular joints and those numer- 

 ous transverse striae or lines of false bedding so common in 

 the New Red Sandstone, with occasional lumps of harder cal- 

 careous grit. At Sedgely, it is a hard, red, slightly calcare- 

 ous sandstone, with spots of green passing upwards into red 

 argillaceous marl. These localities are all on the west side 

 of the fields, and the strata invariably dip to the west, or 

 from the underlying coal measures ! On the eastern side of 

 the coal field these sandstones are much more obscured by 

 coarse gravel, but in several situations they are seen to be 

 overlaid by a red calcareous conglomerate, which also dips 

 away from the coal-field, or to the east. The great thickness 

 of these lower sandstones has been recently proved by the 



