Hydrothermal Altered Sediments from Contact Zones with Sills in the North Trough of the Guaymas Basin, Gulf of California

Abstract—Chemical composition of the Upper Pleistocene sediments (turbidites interbedded with hemipelagic sediments) from contact zones with basalt sills in the Guaymas Basin, Gulf of the California (DSDP Hole 481A), was studied by the methods of XRF and ICP-MS. Alteration for most macroelements in these sediments is not or slightly. This is not indicates immobility or slightly mobility of these elements, as a process of a distribution of elements occurs inside of sediments without a change their bulk chemical compositions at dissolution/deposition process, in which primary diatoms, opal CT, quartz, and clay minerals. In results, as a whole there is no change in the content of macroelements in sediments. Whereas, the contents Corg, Li, Cu, As, Mo, Ag, Cd, Sb, Ta, W, Tl, Pb, Bi strongly decreasing in altered sediments from contact zones with sills.