LIMESTONE

 Limestone is formed over millions of years from the accumulated skeletons of sea-dwelling creatures such as mollusc and corals.

As the island of Jamaica slowly subsided beneath the sea during the early Cenozoic, about 45 million years ago, the initial deposits of limestone were contaminated by debris still being washed off the remaining land area and were given the name Yellow Limestone during the nineteenth century. This impure limestone lies directly on the eroded remnants of the volcanoes of the Cretaceous period.

As the island sank completely below sea level, the contaminating run-off from the land area ceased and pure White Lmestone was deposited on top of the Yellow for a period of about thirty million years. This White Limestone presently covers about 70% of the island. The drawing on the right shows the present distribution (igneous rocks protruding through the limestone are colour-coded green and the red boundary delimits the Cockpit Country)

The Cockpit Country comprises much of the Troy-Claremont Limestone Formation, the oldest layer of the White Limestone Group that was laid down on the Yellow Limestone Group during the mid Eocene age. The Troy Limestone (to the west) consists of well-bedded to massive yellow-brown to pink recrystallized limestones and dolomites that are generally unfossiliferous because it was resubmerged by tectonic activity and has recrystalised. The Claremont Formation (on the east) is more recent and consists of evenly-bedded, bioclastic, limestones. which are rich in fossilised molluscs upto five feet in diameter. The Barbecue Bottom fault marks the division between these two formations.

Low-lying areas and flanks of the Cockpit Country are floored by alluvial clay, derived from the weathering of limestone. We value your feedback and comments:

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