CHAPTEE XVIII. 



THE MOUNTAIN LIMESTONE. 



The Carboniferous or Mountain Limestone of English ; Calcaire Carbonifere, 

 Calcaire Anthracifere, Calcaire de Transition of French Authors. 



MUSEUMS: Geological Society, Bristol, York, and Dudley, Institutions; 

 Collection of Mr. Gilbertson, now transferred to the British Museum ; 

 that of Dublin, &c. 



AUTHORS : Martin, Miller, Sedgwick, Phillips, Murchison, Conybeare. 



CHARACTERISTICS : A Marine deposit, abounding in Zoophytes (chiefly 

 Crinoidea), Shells, Fishes, and other marine exuviae, remarkable for the 

 abundance and variety of its mineral productions, its caverns, and 

 fissures. 



THE practice of bestowing new names on objects familiar to 

 science, is neither commendable nor useful ; yet the forma- 

 tion we are about to describe seems to require some more 

 appropriate appellation than that by which it is usually 

 distinguished. The term carboniferous properly signifies 

 "bearing coal," whereas this limestone, with perhaps the single 

 exception of the Berwickshire coal-field, never contains that 

 substance ; while the name mountain-limestone is equally ill 

 bestowed on a rock, which, both in this country, Ireland, 

 and on the Continent, frequently occupies valleys. 



GEOGRAPHICAL DISTRIBUTION. It is extensively deve- 

 loped over the northern and western parts of England, in 

 Derbyshire, Shropshire, Somersetshire, and Gloucestershire, 

 lying between the coal and the more ancient rocks beneath, 

 In Cumberland and Westmoreland it attains considerable 

 elevations, partly encircling the mountains of slaty rocks : 

 while in Derbyshire and Yorkshire it rises to independent 

 peaks and hills, presenting scenery of the wildest and most 

 picturesque character. 



MINERAL PRODUCTIONS. These are more abundant in 

 this formation than in any hitherto described. The rock 

 itself is of sub-crystalline texture, and is susceptible of a high 



