Structural Evolution of the Rock Creek Gold Deposit, Seward Peninsula, Alaska

摘要

Sheeted quartz veins at Rock Creek contain an indicated gold resource of 404,000 ounces (oz) at a grade of 1.31 grams per ton (g/t). The deposit, located on the Seward Peninsula, 12 km north of Nome, Alaska, occurs in variably graphitic greenschist-facies schist, fine-grained quartzite, and dirty marble of the lower Paleozoic to upper Proterozoic Nome Group. The veins at Rock Creek, as at many prospects in the southwestern Seward Peninsula, are hosted by the most carbonaceous part of the Nome Group. These strata underwent complex polyphase deformations that were progressively less penetrative through time. They include four distinct styles of folding, followed by an episode of thrust faulting. The Mid-Cretaceous dilational vein system formed during the onset of D₄ deformation along the northeast-trending Albion fault.