HILL: GEOLOGY OF JAMAICA. 51 
3b 
Sawkins), here composed of volcanic tuff with conchoidal fracture and 
Weathering into rusty red clays, metamorphosed shale, and occasional 
ECAR XI CEOS VDE 
FreunE 15. Barrett's Section, near Bath. 
pieces of contained impure limestone. About a mile up the Plantain 
Garden River the stream has a steep V-shaped canyon surrounded by 
hills. A new highway which is being constructed shows fine cuts of the 
Prevalent Minho formation. In this we found exposures of hard strata 
of Cretaceous limestone, aggregating several feet in thickness, but the 
vegetation was so thick that the latter fact could not be determined. 
positively, 
Figurn 16. Plantain Garden River Section at Bath. c. Trappean Material 
above. b. Cretaceous Limestone. a. Trappean Material below 5. 
Below the limestone (b) are altered shales and decomposed volcanic 
Conglomerates, some of which weather into dark colored chocolate or 
vermilion colors. 
Tn nearly all the localities of the Jamaican Survey, with the excep- 
tion of the Jerusalem exposure, the limestones have the appearance of 
localized beds in the midst of the general material of the Blue Mountain 
Series! and not of widely extending or persistent strata. 
These beds occupy no persistent horizon but occur at various inter- 
Vals in the great aggregation of deposits. Our observations incline us to 
gree with Sawkins? that “it would appear from the occurrence of the 
imestono in detached places that it originally formed isolated reefs.” 
The marls succeed the bedded limestones in ascending series, and 
Vary from 50 foot to an inch in thickness as seen in the clays along the 
inho, at Ballard's abovo Clarendon, at Pennant's Great House, and 
Trout Hall. In general, these clays contain fossils which represent 
Mtermittent, life colonies which have found temporary habitation in 
Periods of quiescence during the irregular deposition marking the forma- 
tion of the earlier part of the Blue Mountain Series, 
: Barrett, Quart. Jour. Geol. Soc. London, 1860, Vol. XVI. pp. 325, 890, 
2 
2m t y 
org The Metamorphosed Series, Trappean Series, Black Shale, and Conglomerate 
Sawkins, 
E ee 
