Use of Fe/Mn Oxide-Rich Fracture Coatings in the Geochemical Exploration for Precious Metal Deposits: A Comparison with Standard Rock and Soil Geochemistry

摘要

The effectiveness of Fe/Mn oxide-rich fracture coatings as a geochemical medium for precious metals exploration is evaluated relative to conventional litho- and pedogeochemistry. Sampling of fracture coating, rock, soil, and stream sediments in areas of known disseminated gold in the Pinson Mine and Preble Prospect and potential bonanza-type near the Comstock Lode mineralization indicates that the technique is scientifically valid. Fracture coating samples contained an average of 18.8, 7.5+, 7.4, and 4.5 times more Sb, Au, As, and Hg, respectively, than rock samples at Pinson, and 10.2, 5.2+, 2.7, and 1.6 times more Sb, Au, As and Hg, respectively, than rock samples at Preble. A higher contrast is obtained relative to soil and stream sediment samples. The geochemical halos obtained from fracture coating samples cover larger areas than those obtained from rock or soil samples and accurately reflect the locations of known mineralization. Larger exploration targets are defined as a result.