Host rockLimestone,Granite · "Vinini Formation", "Garden Valley Limestone "
Associated rockAlkali-Granite (Alaskite),Rhyolite,Shale,Chert,Argillite · "Mount Hope Igneous Complex", "Mt Hope Rhyolite Dome"
StructureRoberts Mountains Thrust fault, Host rocks in the deposit area are cut by several faults: the N35W-trending Ravine Fault, the N60W-trending Bisoni Fault, the N80W-trending Tia Fault, and the N75W-trending South Fault. The Mount hope Fault is arcuate, changing orientation dramatically from about N30E north of the mine area to N75W south of the mine area, with the ?bend? in the fault occurring in the vicinity of the molybdenum deposit.
AlterationSkarn development, tactite-hornfels at the historic lead zinc deposits.\nThe porphyry molybdenum deposit is characterized by a variety of alteration assembages attendant upon the mineralization.These include argillic-propylitic, argillic, potassic-phyllic, potassic, silica-flooded, and bioite zones, roughly concentrically zoned outward from the core of the hydrothermal system.