Microscopic distribution of trace elements in minerals (chlorites, sulfides, sulfates) in submarine hydrothermal systems

We have analyzed trace elements in two types of hydrothermal precipitates using the Los Alamos Nuclear Microprobe. Chlorites and epidotes in basalt were analyzed from the Samail Ophiolite of Oman. Sulfide and sulfate minerals were analyzed from samples of active chimney walls from 21°N, East Pacific Rise. These samples are ideal for our study because of the extensive background information available on processes and component characteristics. Initial results indicate significant differences in mobile trace elements between chlorites associated with and those distinctly separate from major stockwork flow zones, consistent with greater water-rock reaction within stockworks. Trace element concentrations across chimney walls also exhibit distinctive patterns which can be correlated with mineral/chemical zonation and possibly also with variations in elemental source.