Silicification of low-magnesium mollusc shells from the Upper Oligocene of Antigua, Lesser Antilles.

Silicified molluscs, namely the oyster Hyotissa and the scallop Aequipecten?, are commonly preserved as silica in the carbonate successions on the island of Antigua. These fossil assemblages are located within the Antigua Formation, above and adjacent to a variety of volcanic and volcaniclastic rocks, suggesting, on geological grounds, an igneous source for the silica. Energy dispersive spectroscopy (EDS) and cathodoluminescence (CL) have been applied to characterise the silcification and its conditions of formation which may have been associated with hydrothermal activity