Murchisoris Silurian System. 41 



or twelve in diameter.* These grits are frequently calca- 

 reous, and are composed chiefly of grains of deep red 

 quartzose sand, with white specks of decomposed felspar. 

 Although, therefore, they do not much resemble the ordi- 

 nary strata of the New Red Sandstone, they are unlike any 

 beds in the Old Red System. And though it may be diffi- 

 cult, nay, in some cases impracticable, to distinguish the 

 calcareous concretions of the one system, from the corn- 

 stones and limestones of the other, we have a safe guide in 

 the order of superposition ; and the absence of the fishes, 

 and organic remains of the Old Red Sandstone, is negative 

 evidence of some use in assisting the inquirer. 



" In subsequent remarks upon the carboniferous deposits of these 

 tracts, it will be explained how the coal measures which appear in 

 patches in the bed and banks of the Severn, have been brought to light 

 from beneath this cover of the Lower New Red Sandstone. This 

 member of the system is developed on both banks of the Severn, north 

 of Bridgenorth, or between that town and Madeley, leaving no doubt of 

 its age since it is seen overlying, and dipping away from a thin zone of 

 coal at Tasley and Coughley ; and where some of the harder courses also 

 contain calcareous sandstones. 



A most instructive transverse section can also be made by passing 

 from the high terrace of Apley to the lower ridges, in which are situated 

 the park and house of Mr. Whitmore. The change observed in passing 

 from the fine sandy and loamy soil of the upper and middle portion, to 

 the cold argillaceous surface of the lower division of the system, is quite 

 as marked, as the contrast between the agricultural surface of the New 

 and Old Red Sandstones, where those systems are brought together in 

 Gloucestershire and parts of Worcestershire. So complete is the resem- 

 blance between this lower member of the New Red and the Old Red 

 Sandstone itself, that I confess it was only the clear order of superposi- 

 tion which convinced me, that this zone of sandstone and clay really 

 formed part of the younger system. Near Apley Park Lodge, quarries 



* " The stone was also formerly much extracted for the furnace hearths of 

 blast-houses, but experience has taught the iron-masters, that many other sandstones 

 are equally serviceable for that purpose. The coarser beds contain small fragments 

 and concretions of marl. They are also used as building stones." 



G 



