Late Cenozoic strain field and tectonic setting of the northwestern Great Basin, western United States: Implications for geothermal activity and mineralization

In the northwestern Great Basin, relatively high rates of recent (<10 Ma) westnorthwest extension have absorbed a northwestward decrease in dextral motion along the Walker Lane. Abundant geothermal fields and a number of young (< about 7 Ma) epithermal mineral deposits occur in this region and are most commonly situated along north- to northeast-striking structures. This hydrothermal activity may result from a transfer of northwest-trending dextral shear in the Walker Lane to west-northwest extension in the northern Great Basin. Enhanced extension favors dilation and deep circulation of aqueous solutions along north- to northeast-striking structures oriented perpendicular to the extension direction. The individual belts of geothermal fields probably reflect loci of strain transfer within this rapidly evolving region.