Evidence for a Battle Mountain‐Eureka crustal fault zone, north‐central Nevada, and its relation to Neoproterozoic‐Early Paleozoic continental breakup

Abstract

[1] Combined evidence from gravity, radiogenic isotope, and magnetotelluric (MT) data indicates a crustal fault zone that coincides with the northwest-trending Battle MountainEureka (BME) mineral trend in north-central Nevada, USA. The BME crustal fault zone likely originated during Neoproterozoic-Early Paleozoic rifting of the continent and had a large influence on subsequent tectonic events, such as emplacement of allochthons and episodic deformation, magmatism, and mineralization throughout the Phanerozoic. MT models show the fault zone is about 10 km wide, 130-km long, and extends from 1 to 5 km below the surface to deep crustal levels. Isotope data and gravity models imply the fault zone separates crust of fundamentally different character. Geophysical evidence for such a long-lived structure, likely inherited from continental breakup, defies conventional wisdom that structures this old have been destroyed by Cenozoic extensional processes. Moreover, the coincidence with the alignment of mineral deposits supports the assertion by many economic geologists that these alignments are indicators of buried regional structures.INDEX TERMS: 0905 Exploration Geophysics: Continental structures (8109, 8110); 0920 Exploration Geophysics: Gravity methods; 0925 Exploration Geophysics: Magnetic and electrical methods; 1040 Geochemistry: Isotopic composition/chemistry; KEYWORDS: crustal structure, geophysics, isotope geochemistry, Nevada-USA, plate tectonics Citation: Grauch, V. J. S., B. D. Rodriguez, V. Bankey, and J. L. Wooden, Evidence for a Battle Mountain-Eureka crustal fault zone, north-central Nevada, and its relation to Neoproterozoic-Early Paleozoic continental breakup,

Multicommodity mineral systems analysis highlighting mineral prospectivity in the Halls Creek Orogen

“…Deep crustal-scale structures are understood to control lithospheric architecture and therefore influence the development and emplacement of a wide range of mineral deposits (Bierlein et al, 2006;Grauch et al, 2003;McCuaig et al, 2010;McCuaig and Hronsky, 2014;White et al, 2014;White and Muir, 1989). In some regions, disparate mineral deposits that formed in diverse tectonic settings and at vastly different times are present along, or adjacent to such fundamental structures (McCuaig and Hronsky, 2014;O'Driscoll, 1981).…”

Three-dimensional geologic model of the northern Nevada rift and the Beowawe geothermal system, north-central Nevada

“…Major geologic components include thrust sheets of Paleozoic siliciclastic and carbonate rocks of the Antler orogenic belt, Mezozoic to Paleogene granitoid intrusions, Eocene and Oligocene volcanic rocks, and Neogene bimodal dikes, volcanic rocks, and basin fi ll-all of which are dissected by two sets of Neogene normal faults. The discovery of numerous gold-silver deposits, including those along the Battle Mountain-Eureka mineral trend (Roberts, 1966) and the Carlin trend (Roberts, 1960) led to many geologic and geophysical studies focusing on the origin and distribution of these deposits (Berger and Bagby, 1991;Christensen, 1995;Hildenbrand et al, 2000;Grauch et al, 2003). Glen and Ponce (2002) describe several large-scale, NNW-trending, arcuate, mid-Miocene crustal structures in northern Nevada, including the eastern northern Nevada rift, which passes just west of the Beowawe geothermal system and is the focus of this study.…”

Modelling of high‐resolution aeromagnetic data to decipher structural deformation in parts of Kaladgi basin, Peninsular India

“…The collection of high-resolution aeromagnetic data over large areas of continents provides new opportunities to constrain and understand geological evolutions of poorly exposed or buried terrains (e.g., McLean et al 2009;Stewart and Betts 2010). Magnetic surveys are successfully applied to outline banded iron formations in greenstone belts (Prevec and Morris 2001), magnetite-rich granitoids (Wennerstrom and Airo 1998), and structural analysis (Betts, Valenta and Finlay 2003;Grauch, Rodriguez and Bankey 2003;Aitken and Betts 2009) and mapping concealed basement terrains (Stewart and Betts 2010). In Precambrian terrains, recognition of structures at large and small scales is often hindered by inaccessibility and insufficient exposure that leads to poorly resolved tectonic histories (Johnson and Stewart 1995).…”