Petrographic analyses of Mio-Pliocene carbonates on Isla de Mona, Puerto Rico.

摘要

Isla de Mona is a carbonate island located in the Mona Passage 68 km west of Puerto Rico. The tectonically uplifted island is 12 km by 5 km, and forms a raised flat-topped meseta. The meseta tilts gently to the south and is bounded by near vertical cliffs on all sides. These cliffs rise from 80 m above sea level north to 20 m above sea level on the southern coast. The meseta consists of two Mio-Pliocene carbonate units, the lower Isla de Mona Dolomite and the upper Lirio Limestone. Numerous flank margin caves have developed at this contact and ring the periphery of the island. Rock samples were taken from within some of theses caves; Cueva del Aleman and Cueva de Agua, Punte Los Ingleses. Compared to previous studies where samples were take from surficial outcrops, these samples show differences in degree of alteration and allochem abundance and type.