Mineralogy and petrology of the Haiti Cretaceous/Tertiary section

The Cretaceous/Tertiary sections in Haiti consist of a sequence of graded beds of turbidity current or gravity flow origin. Each section may consist variously of five major constituents: (1) black glass, (2) brown globules, veinlets and blobs, (3) argillaceous limestone clasts, (4) white clasts and shards, and (5) a fine-grained matrix rich in smectite, zeolites and calcite. In addition, there are trace amounts of a high-calcium yellow glass. The black glass particles are vesicular, apparently unaltered with an andesitic to dacitic composition, and in sharp contact with the secondary matrix and veinlet alteration products. The brown globules, veinlets and blobs consist of a palagonite-smectite mix of a distinctly different composition than the black glasses. White clasts and shards of a still different (more hydrated) composition are also present. All of these materials are sometimes associated with accretionary lapilli(?). The hydration or alteration products—brown globules, white clasts and shards, and matrix—amount to something in excess of 95% of the total deposits. The sedimentology, mineralogy and petrology of the Haiti sections has provided a record of a sequence of probable volcanic events.