Deep regional resistivity structure across the Carlin Trend

The genesis of gold deposits along the Carlin trend is not fully understood. Many of the significant mineral deposits in the Carlin trend were formed during the Tertiary as a result of interrelated high-angle basin-and-range faulting, intrusive igneous activity, and hydrothermal processes (Radtke, 1985). According to Shawe (1991), the linearity of the gold deposits along the Carlin trend and the sub-parallel Battle Mountain-Eureka trend suggests that deep-penetrating regional structures controlled the emplacement of magmas generated in the lower part of the crust or upper mantle, and either provided hydrothermal fluids or caused heating of ground waters that were responsible for transport and deposition of the gold ores. To investigate crustal processes that may have contributed to the genesis of gold deposits along the trend, a regional southwest to northeast profile of magnetotelluric (MT) soundings was acquired in 1996 (line MT-MT′, Fig. 1). Two-dimensional resistivity modeling of the MT profile is being used to place constraints on possible heat or magma sources and possible tectonic controls on the linear distribution of mineral deposits.