Is salt present in the Caribbean?

Abstract

Salt can occur in deep water and often pierces the sea floor. It was cored at Site 546 below 4 km of water offshore Morocco. Piercement structures are seen in deep-sea sediments in many places in the Atlantic, Indian and Pacific oceans. Salt is present in the Gulf of Mexico, on Cuba and in the Bahamas, in Colombia and in Guyana. Common seafloor features in the Colombia and Venezuela basins are interpreted to be seamounts, in line with the basins’ presumed Pacific, oceanic origin. They are surrounded by “moats”. These are withdrawal rim synclines classically associated with salt diapirs. A diapir on a Venezuela Basin seismic line is directly comparable with the cored Gulf of Mexico Challenger Dome. Both rise above the sea floor. Diapirs often carry exotic material to the surface. Cretaceous basalt crops out on cap rock above the Alderdice Bank diapir, offshore Lousiana. Seismic data from Venezuela Basin shows diapirs pushing through and rotating basalt of Horizon B”, showing that the latter is a unique layer, not the top of an igneous plateau. The Venezuela Basin diapir lifts Horizon B” to the sea floor. Sea floor dredge recovery of igneous exotics prompts interpretations that the structures are igneous. Diapiric features in the Caribbean should be carefully surveyed by detailed seismic, gravity, magnetic and heat flow data, and cored in their cap rocks. If salt is present, the Caribbean has inter-continental origins. Hydrocarbons should be expected.

AAPG Datapages/Search and Discovery Article #90330©2018 AAPG Hedberg: Geology of Middle America – the Gulf of Mexico, Yucatan, Caribbean, Grenada and Tobago Basins and Their Margins “Integration of the geology of the area from the southern onshore of North America to the northern onshore of South America”, Siguenza, Guadalajara, Spain, July 2-5, 2018