Mineral Deposits of the Bullard Mineral District, Harcuvar Mountains, Yavapai County, Arizona
KeywordsArizona Geological Survey Open File Reports
Bullard Mineral District
metamorphic core complex
Basin and Range extension
MetadataShow full item record
CitationSpencer, J.E. and Reynolds, S.J., 1992, Mineral Deposits of the Bullard Mineral District, Harcuvar Mountains, Yavapai County, Arizona. Arizona Geological Survey Open File Report, OFR-92-01, 19 p.
DescriptionThe Bullard mineral district is one of approximately 15 mineral districts in west-central Arizona and southeastern California that are related to large-displacement, regionally low-angle normal faults known as detachment faults (Spencer and Welty, 1986; Roddy and others, 1988). Detachment faulting occurred during regional mid-Tertiary extension in the Basin and Range province and was associated with formation of extensional basins and elevated geothermal gradients (Spencer and Reynolds, 1989a). Mineral deposits related to detachment faults formed within this tectonic setting and were the result of hydrothermal ascent of basin brines along detachment faults (Wilkins and others, 1986). One of these districts includes the Copperstone mine, which has yielded several hundred thousand ounces of gold (Spencer and others, 1988). This article briefly describes the mineral deposits of the Bullard district and summarizes gold-assay data from numerous surface samples and from two drilling programs. Geologic similarities between the Bullard district and Copperstone deposit suggest that significant gold deposits could be present in the subsurface in the Bullard district.
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North Bounding Coordinate34.2008
South Bounding Coordinate33.7636
West Bounding Coordinate-113.873
East Bounding Coordinate-113.137
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Animal health problems caused by silicon and other mineral imbalancesMayland, H. F.; Shewmaker, G. E. (Society for Range Management, 2001-07-01)Plant growth depends upon C, H, O, and at least 13 mineral elements. Six of these (N, K, Ca, Mg, P, and S) macro-elements normally occur in plants at concentrations greater than 1,000 mg kg(-1) level. The remaining micro-elements (B, Cl, Cu, Fe, Mn, Mo, and Zn) normally occur in plants at concentrations less than 50 mg kg(-1). Trace amounts of other elements (e.g., Co, Na, Ni, and Si) may be beneficial for plants. Silicon concentrations may range upwards to 50,000 mg kg(-1) in some forage grasses. Mineral elements required by animals include the macro-elements Ca, Cl, K, Mg, N, Na, P, and S; the trace or micro-elements Co, Cu, Fe, I, Mn, Mo, Se, and Zn; and the ultra-trace elements Cr, Li, and Ni. When concentrations of these elements in forages get 'out of whack' their bioavailability to animals may be jeopardized. Interactions of K x Mg x Ca, Ca x P, Se x S, and Cu x Mo x S are briefly mentioned here because more detail will be found in the literature. Limited published information is available on Si, so we have provided more detail. Silicon provides physical support to plants and may reduce susceptibility to pests. However, Si may have negative effects on digestibility and contribute to urinary calculi in animals.