i 



Mr. De la Beche on the Geology of Jamaica. 173 



rock mixed with the limestone near New Forest, is in a great measure calca- 

 reous. The white limestone of this place varies in its degree of hardness, 

 but is principally compact ; in one instance I observed it of a crystalline struc- 

 ture with thin spathose divisions. 



Quitting the Plain or Savannah above-mentioned, and ascending Marlbro' 

 Hill, white limestone will be seen dipping to the S.W. The May Day Hills 

 are composed of a mixture of white limestone, red sandstone, and white 

 marls, which are continued down the beautiful valley with the inharmonious 

 name of Mile Gully, a name moreover altogether inappropriate as applied to 

 this valley, which is many miles long, and any thing but a gully. The general 

 dip of the whole limestone formation of Manchester appears to be at various 

 angles to the S.W. 



The Round Hill in Vere is formed of a continuation of the Manchester 

 white limestones, and is remarkable for the warm saline spring that rises out 

 of the limestone near its base, at the place called the Bath*. The white lime- 

 stone formation would indeed seem in some measure saliferous, for salt is 

 found in the Long Mountain near Kingston, produced apparently by the eva- 

 poration of saline dippings from the rockf . Among the limestones of the 

 Bath in Vere, is one of a roseate flesh-colour, which might be made useful 

 for ornamental purposes. 



The Mocho Mountains in Clarendon are composed of the same rocks as 

 those of Manchester, the red sandstone being much more scarce. The stra- 

 tification of the Mocho Mountain limestones is in general difficult to deter- 

 mine, from the thickness of the forests by which they are covered, and from 

 the decomposed surface of the beds, which are often honey-combed to a con- 

 siderable depth. 



The traverse over these mountains by the Rock road exposes a considerable 

 quantity of compact white limestone, the beds of which would seem to vary 

 from 3 to 20 feet in thickness ; for I observed blocks that must have belonged 

 to rocks of at least the latter size. Between the higher part of the road and 

 Four Paths estate, white marls come in, and are succeeded by a yellowish 

 and rather arenaceous rock effervescing with acids. The glen through 

 which the road winds to Halse Hall Crawle presents cliffs in which the white 

 limestones appear to dip to the Southward at about an angle of 13°. In two 

 or three places on the ascent, red sandstone will be observed interstratified 



* I found the temperature of this water = 92" Fahrenheit. 



t I was informed that the spring at Port Henderson was saline, and that it rose from white 

 limestones. 



