Placer gold settings within an alpine glaciated environment, Granite Creek, Yukon (NTS 105M/14)
Description
Alpine glaciers from cirques of Granite and Albert creeks have deformed and reworked sediments in the Granite Creek valley and deposited locally sourced gold. Placer mining operations in the valley allowed detailed study of sedimentary deposits. The main units identified are from at least two glacial episodes which advanced farther than the previously mapped limits. Thick sequences of advance and retreat outwash blanket the till and represent high energy depositional environments. At least one proglacial lake formed due to ice-damming of lower Granite Creek by the Cordilleran Ice Sheet. We provide a stratigraphic record extending approximately 130 000 years and have correlated alpine till units to MIS 4, which has not been identified elsewhere in central Yukon. Multiple gold-bearing sedimentary units are found in the stratigraphy, representing glacial, interglacial/interstadial, and modern processes. This work highlights processes important to gold concentration that can be applied to other alpine glaciated areas with proximal gold mineralization.