Outlines of Geology.' 33 



of very extensive occurrence, and involving the history ol Some 

 important deposits, more especially, that of coal. I shall not 

 stop here to explain the differences of opinion respecting the 

 Wernerian phraseology applied to this rock, but it will be found 

 that a very analogous substance occurs at greater depths, or 

 among older rocks, and is. then emphatically termed old led sand- 

 stone ; the terms, new red sandstone, red marl, or the mere pro- 

 vincial phrase red ground being applied to that formation which 

 follows the oolite, and which we may now proceed to examine. • 



In the first place, in regard to situation, the red marl extends, 

 without material interruption, from the east of Somersetshire to the 

 northern bank of the Tees in Durham. The map shows the occur- 

 rence of coal, beds in this district, the great coal formations, or coal 

 basins as they are often called, being apparently deposited in the 

 inferior or mountain limestone, and covered by, and alternating 

 with red marl, or some of the substances with which it is directly 

 associated. It may not be irrelevant to take a general view of the 

 positions of this rock in the several coal counties, and to notice 

 the other substances which form its constant or occasional ac- 

 companiments; and in doing this shall I make use of Mr. Phillips's 

 abstract of the papers in the Geological Transactions i elating to 

 this formation. 



Red sandstone generally forms a flat and low countiy, or where 

 elevated into hills, their slopes are gentle, and their outline 

 rounded. In the midland counties, it is traversed for a con- 

 siderable length by the Severn ; and the Ouse and Trent, streams 

 tributary to the Humber, take a long course through its plains. in 

 the north. In the south-east part of Durham it exhibits strata 

 of various colours, containing coal and gypsum. In Westmoreland 

 it covers a considerable plain on the west of the range of moun- 

 tains, of which Crossfell is the highest, and which is near the 

 south-western extremity of the great Newcastle coal-field. The 

 southern parts of Lancashire, the north of Shropshire, and the 

 whole of the intervening county of Cheshire, are principally cha- 

 racterized by their plains of red marl, and in Worcestershire it is 

 also a prevailing rock, as also in various parts of Derbyshire, 



Vol. XX. D 



