Distribution of elements in Gulf of Mexico sediments

The Gulf of Mexico has been studied from many viewpoints as a modern analog of ancient geosynclines. Because few details of the geochemistry of its sediments have been reported, we made a reconnaissance survey in which concentrations of eleven elements (Ba, Ca, Fe, Mn, Ni, Rb, Sr, Ti, Y, Zn, Zr) were measured by X-ray fluorescence spectrometry in six piston cores from canyon, fan, abyssal hill and abyssal plain environments of the Gulf. To complement the areal coverage, profiles of concentration versus depth were determined in these cores which contain sediments of upper Miocene to Holocene age. The results provide additional evidence of post-depositional migration of Ba and Mn and affirm the observation in Pacific sediments that Mn concentration is inversely related to rate of accumulation. Ti is less abundant in the uppermost sample of each core and is deficient by 2X in a pelagic Segsbee Knoll core relative to nearby abyssal plain sediments. Low values of Sr/Ca in argillaceous samples indicate a depletion of Sr which is attributed to intensive weathering. Previously published Zn concentrations in Gulf of Mexico sediments appear to be an order of magnitude too high. No significant areal variations are readily detectable from the trace element data obtained except for Mn and Zn, which are slightly enriched in abyssal plain sedments.