Abstract

Disseminated gold deposits found in the Great Basin in central and eastern Nevada and western Utah occur in Paleozoic sedimentary rocks or Cenozoic volcanic rocks. The gross trend of the gold occurrences appears to be subparallel to the Wasatch hingeline. In contrast, some gold occurrences may be related to Mississippian Antler Mountain fluvial systems perpendicular to the Wasatch hingeline.

Early Paleozoic carbonate deposition in eastern Nevada and western Utah was interrupted during the Late Devonian and Mississippian times by the deposition of siliciclastics shed eastward off the Antler orogenic highland caused by collision of an Island Arc with western North America. Three pulses of these siliciclastic sediments recorded in the stratigraphic record may have introduced significant amounts of gold and other metals between the head waters west of the Carlin/Jerritt Canyon area and the basin edge east of the proto-Oquirrh BAsin area in central Utah. These sediments were in turn subthrust beneath upper plate host rocks during Mesozoic and Tertiary events. It is postulated that trace amounts of gold and other metals were likely present in the Mississippian fluvial rocks and were locally concentrated in some places by placer processes. Hydrothermal fluids then leached the gold from the lower place sediments and redeposited it in upper plate traps as disseminations during the Cenozoic.