Figure 9. Subset of Plate 3 over the Independence Mountains, Elko County (F, Fig. 6). The quartz index map highlights the McAfee Quartzite within the undifferentiated unit Ds of Crafford (2007) that composes the Roberts Mountain allochthon (Mississippian Antler orogeny) in this area. Small outcrops of cherts and jasperoids were also identified as quartz bearing within this allochthon. The mapped jasperoid is shown in Figure 10. Units of chert and/or argillite within the Devonian–Permian Schoonover Sequence (part of the undifferentiated Golconda terrane, GC, of Crafford, 2007) in the northwestern mountains were also mapped as quartz bearing. Exposures of identified quartz in the Golconda terrane parallel the general southwest-northeast strike of the many faults in this area (Miller et al., 1984) that were created during thrusting of the Golconda allochthon during the Permian–Triassic Sonoma orogeny. JC—Jerritt Canyon mine. CM—California Mountain mine. ED—East Dash mine. SV—Saval mine. BW—Burns West mine. ASTER—Advanced Spaceborne Thermal Emission and Reflection Radiometer. To access a full-resolution PDF of this figure, please visit http://dx.doi.org/10.1130/GES00126.S9 or the full-text article on www.gsajournals.org.