Precious Metal Deposits Of The Carlin Trend

Author : Melanie Nicole Newton
Publisher :
ISBN 13 :
Total Pages : 352 pages
Book Rating : 4.:/5 (12 download)

DOWNLOAD NOW!

Download or read book Characterization of Gold and Related Mineralization at the North Bullion Carlin System, Railroad Project, a Nevada Carlin-type Gold Prospect written by Melanie Nicole Newton and published by . This book was released on 2015 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the North Bullion Carlin system, a Nevada Carlin-type gold prospect located on trend with the large Carlin-type gold deposits (CTGD) of the Carlin Trend, identified characteristics of ore and alteration mineralization, mineral paragenesis, and pyrite and whole rock geochemistry that are similar to characteristics that typify Carlin-type gold deposits. The North Bullion Carlin system is hosted in Devonian shelf carbonates and the Mississippian overlap assemblage, host rocks that are different from typical CTGD shelf-slope carbonate assemblage host rocks. The mineralogy and ore-stage gold-bearing pyrite rims at North Bullion are not as well developed as they are in typical CTGD, and alteration and geochemical relationships are subtle. Yet the North Bullion Carlin system exhibits many of the features observed in large deposits. Observations demonstrate that North Bullion Carlin system is a CTGD, potentially on the periphery of a larger system. Gold mineralization at the North Bullion Carlin system is controlled by structures, which include the North Bullion Fault Zone and the Massif Fault, and stratigraphic controls, which include the lithologic contacts between the Devonian Devils Gate Collapse Breccia, Mississippian Webb Formation, and Mississippian Chainman Formation. The uppermost horizon of gold mineralization is located at a lithological contact between limestone and mudstone within the Webb Formation, and grade decreases away from this contact in the mudstone. The lowermost horizon of gold mineralization is located within the Devonian Devil's Gate collapse breccia and the multi-lithic tectonic breccia along the North Bullion Fault Zone and Massif fault. Gold mineralization does not extend above the uppermost dacite dikes and sills within the Mississippian Chainman Formation, suggesting the dacite dikes and sills provided a local seal to the deposit. Cross-cutting relationships, textures, and geochemistry indicated the presence of four generations of pyrite. At the deposit scale the North Bullion Carlin system exhibits characteristics of ore, alteration, and mineral paragenesis that are typical of Carlin-type gold deposits, but the mineralization is subtle and not as well developed as in large, high-grade deposits. At the micro-scale the ore pyrites, and whole rock geochemistry are similar to typical Carli-type gold deposits. The Carlin-type pathfinder trace elements, As, Hg, Sb, and Tl, best correlate with gold in ore-stage mineralization. Statistical analyses of whole rock geochemistry indicate that Ba, Mn, Al, P, Cr, and V are the elements that provide the best vector to ore and could identify the periphery of gold mineralization.