485 



which have shattered and elevated the coal measures, and partly to 

 extensive denudation. It is natural therefore to inquire how many 

 other coal-fields may still lie buried beneath the new red sandstone 

 of the adjoining district. 



In relation to this point of great practical importance, Mr. Mur- 

 chison formerly offered some conjectures, when speaking of the proba- 

 ble passage of the 10-yard coal of the Dudley field beneath the new 

 red sandstone, which there flanks it on the east and west. That 

 geologist now informs us that his conjectures have been verified, 

 and that at Christchurch, one mile beyond the superficial boundary 

 of the coal-field, the 10-yard and other seams have been reached by 

 borings carried down to the depth of nearly 300 yards. Adverting 

 to this discovery, he directs attention to the possible extension of 

 other carboniferous tracts beneath the surrounding new red sand- 

 stone of Shropshire, Worcestershire, Staffordshire, and other cen- 

 tral counties. 



It is clear that these geological considerations must be duly 

 weighed by those who speculate on the probable future duration of 

 British coal, according to the actual or any assumed rate of con- 

 sumption. 



Mr. Murchison, in describing the Dudley and Wolverhampton 

 coal-fields, informs us that he has not yet found any fossil remains 

 of decidedly mai'ine origin, like those observed by Mr. Prestwich 

 in Coalbrook Dale. The shells seem to be all of fresh- water ge- 

 nera, and the Megalichthys Hibherti, and other fish occurring at 

 Dudley, of species identical with those of the coal measures of Edin- 

 burgh, may have inhabited fresh water. 



The same author has coloured on an Ordnance Map the super- 

 ficial area of the Silurian rocks connected with the coal-fields above 

 mentioned, and has shown that the Lickey quartz rock between 

 Bromsgrove and Birmingham, of which the geological position has 

 remained hitherto uncertain, is in fact nothing more than altered 

 Caradoc sandstone, a member of the lower Silurian group. The 

 same appears as a fossiliferous sandstone in one district, while in 

 another, it passes into a pure quartz rock, a modification attributed 

 to the proximity of underlying trap, for analogous changes have 

 been seen at neighbouring points where the absolute contact of the 

 sandstone with the trap is visible. 



