Northern Gulf of Mexico continental slope

Abstract

The hummocky continental slope in the northwestern Gulf of Mexico is the result of active salt tectonism and accompanying faulting. Fluid and gassy hydrocarbons rise through the sediment column and along faults causing the formation of gas hydrates, gassy sediments, mud volcanoes and mounds, chemosynthetic communities and authigenic carbonates, reefs, and hardgrounds. Salt activity coupled with processes associated with relative sea level fluctuations create a feedback relationship resulting in the above-mentioned phenomena as well as others such as seafloor erosion at grcat water depths.

Assessing sulfate reduction and methane cycling in a high salinity pore water system in the northern Gulf of Mexico

“…Faulting related to salt tectonism provides the primary conduits for mostly vertical migration and expulsion of hydrocarbons from the deep subsurface petroleum system of the northern Gulf of Mexico (Bouma and Roberts, 1990). Both thermogenic and microbial gas sources have been reported in the Gulf of Mexico based on studies of gases venting at seafloor seeps and sequestered in gas hydrate (Brooks et al, 1984;Sassen et al, 2003;Milkov, 2005 and references therein; Lorenson et al, 2008).…”

“…Hydrocarbons and brines from deep reservoirs in the northern Gulf of Mexico migrate to the seafloor along faults and conduits that are often genetically related to salt-driven tectonics and release of overpressures (Bouma and Roberts, 1990). Seafloor manifestations of the discharge of gas and hydrocarbon-rich fluids include widespread cold seeps, brine pools, mud volcanoes and gas hydrate mounds, often associated with chemosynthetic communities (MacDonald et al, 1996;Roberts et al, 1990;Roberts and Carney, 1997;Sager et al, 2004).…”

Updated checklist and identification of areas of endemism of benthic amphipods (Caprellidea and Gammaridea) from offshore habitats in the SW Gulf of Mexico

“…The distribution of these amphipods in deeper habitats of the northern GM suggests a later incursion of the reptantia species by sediment dumping during the Tertiary (Bouma and Roberts, 1990), or by continuous transport events from shallower waters caused by turbidity currents (Roberts et al, 1999). Similar sediment transport can occur in the Mexican Ridges promoting continuous transport of shallower species to deeper waters.…”

Distinct activity phases during the recent geologic history of a Gulf of Mexico mud volcano

“…Submarine mud volcanoes are a common feature of the northern Gulf of Mexico continental slope (Milkov, 2000), where sediment loading (Bouma and Roberts, 1990), salt diapirism (Reilly et al, 1996), and over-pressured hydrocarbon reservoirs (Neurauter and Roberts, 1994) promote seabed fluid flow and diverse expressions of lumps, mounds, craters, and mud breccia. Eruptive discharge of massive volumes of material has been deduced from seismic evidence showing large craters and steeply sided cones (Prior et al, 1989).…”