ABSTRACT

Grain shape, surface texture and mineralogical analyses were conducted on the Pleistocene and Holocene sands of the northeast Gulf of Mexico shelf and the Mississippi Fan to determine their sources. Two distinct petrologic provinces of sand are present in this area: the Mississippi Province, characterized by spherical quartz grains derived from older strata in the drainage basin of the Mississippi River, and the Eastern Gulf Province, characterized by a mixture of spherical and elongate quartz grains, the former derived from Cretaceous and Tertiary coastal plain strata, the latter derived from sedimentary and crystalline rocks of the southern Appalachian Mountains.

The distribution patterns of the sands of these two provinces on the northeast shelf are very distinct; Mississippi Province sands are found in the western part of the shelf near the Mississippi Delta, while Eastern Gulf Province sands are found throughout the remaining parts of the shelf. The sands of the Mississippi Fan, on the other hand, are a mixture of Mississippi and Eastern Gulf Province sand. Glacial sand is uncommon in both Holocene and Pleistocene deposits of the Mississippi Province.