Gold Standard Ventures Corp. highlighted in their 2014 corporate presentation that “North Bullion and Central Bullion were both gravity- and CSAMT-led discoveries.” The North Bullion gold discovery demonstrates the continued effectiveness of geophysics as applied to gold exploration on the Carlin Trend of northeast Nevada. In combination with geologic understanding and target model development, geophysics provides a cost-effective exploration tool to guide exploration drilling. A sustained, incremental program is critical to realizing the full benefit geophysics brings to the exploration effort. In a program spanning five years, 3587 gravity stations and 51.7 line-km of controlled-source audio magnetotelluric (CSAMT) data have been acquired in a multistage approach. A major structure, called the Bullion Fault Corridor (BFC), hosts two known gold deposits over an 18-km strike length. Gravity, followed up with CSAMT, defines the BFC in detail, as well as hydrothermal alteration products related to the mineralization process. Drill and geologic confirmation is integrated with the geophysics to refine interpretations and adjust ongoing survey design. Application of gravity along the Carlin Trend has been actively used as a structural mapping tool for many years. However, combining the results with CSAMT is a more recent development, particularly along the Carlin Trend.

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