T39 Vapors, Brines, Sulfides, and Mines: Understanding Metal Mobility in Magma-Hydrothermal Systems and Their Supergene Successors (Posters)

Sunday, 31 October 2010
8:00 AM - 6:00 PM
Hall D

THE METAL POTENTIAL OF BLACK SHALES OF EUREKA COUNTY AND NYE COUNTY, NEVADA, USA

Paper number: T39-6
Program: Technical Sessions
Time: 8:00 AM – 6:00 PM

Authors

Abstract

Metalliferous black shales (MBS) are mudrocks which, at least initially, contained relatively high concentrations of organic matter (~2-10% organic carbon) and have been found to maintain high concentrations of some trace metals, e.g., Cd, Ag, Mo, Zn, V, Cu, Ni, and U, during and following diagenesis and weathering. These trace metals are commodities vital to a variety of technogenic applications (e.g. hardened steel) as well as the production of renewable energy and, as such, there is a growing interest in developing accurate regional exploration techniques for MBS. This project is focused on developing a multi-spectral remote sensing technique to determine the metal abundances in surficially-outcropping black shales. The field laboratory is the Upper Devonian Gibellini facies of the Woodruff Formation in central Nevada, USA. The goals of this study are to: 1) correlate surface and sub-surface (accessible via drill core) geochemical and mineralogical data; and 2) utilize remote sensing data to characterize the units, and investigate the possibility of locating similar deposits.

The MBS consist of allochthonous blocks which are surficially exposed in pockets in central NV. The rocks are tectonically deformed and fractured, and the fine-grained nature of the Gibellini facies deposit precludes most macroscopic field techniques for use in facies identification. Thus, the employment of multi-spectral remote sensing could be a valuable tool in locating potentially similar deposits and perhaps MBS in general. Geochemical data indicate that the MBS in the Gibellini facies contain high concentrations of V, ranging from ~3000 to 8000 ppm, and high concentrations of Mo, Se, and Zn. We will present geochemical data for seven transects across four major MBS areas and discuss the application of multi-spectral remote sensing to determine, semi-quantitatively, the composition of the MBS both in Nevada and on a global scale. The results of this study will provide important constraints on the use of remote sensing for MBS exploration.