Mt. Ogden Prospect, Juneau Mining District, Juneau, Alaska, USAi

Regional Level Types
Mt. Ogden Prospect	Prospect
Juneau Mining District	Mining District
Juneau	City Borough
Alaska	State
USA	Country

Location: This prospect is on the west flank of Mount Ogden near the international boundary. It is just under about the center of the north side of section 5, T.40 S., R.73 E. of the Copper River Meridian. This is location T006 of Wells and others (1986). The location is accurate within 1/2 mile.
Geology: The Mount Ogden prospect is in a diorite porphyry stock that covers an area about 4,500 feet by 6,900 feet in size. The stock is marked by sericitic, potassic and chloritic alteration. Molybdenite occurs as sparsely disseminated crystals in the porphyry, in miarolitic cavities in the porphyry, along fractures, in quartz breccia bodies, and in quartz veins. Minor scheelite, fluorite, rhodochrosite, arsenopyrite, sphalerite, galena and gold are present (Wells and others, 1986). Most of this deposit is located on the Canadian side of the international boundary, where it is known as the Nan prospect (Miller and others, 1997). The U.S. Bureau of Mines describe the Mount Ogden prospect as an alaskite intrusive with molybdenite in stockworks, veins, and along fractures (Clough, 1990). Investigations on the Canadian portion of the deposit describe molybdenite clots and fracture coatings that are restricted to aplite dikes and hydrothermally altered felsite (Miller and others, 1997). U-Pb dates from a quartz monzonite porphyry on Mt. Eriksen in British Columbia give an age of 53.5 Ma. A K/Ar date on a biotite-rich, molybdenite-bearing granite dike at the nearby Boundary Creek 2, molybdenum occurrence (TR003) is 59.7 Ma (Miller and others, 1997).
Age: U-Pb dates from a quartz monzonite porphyry on Mt. Eriksen in British Columbia give an age of 53.5 Ma. A K/Ar date on a biotite-rich, molybdenite-bearing granite dike at the nearby Boundary Creek 2, molybdenum occurrence (TR003) is 59.7 Ma (Miller and others, 1997).
Alteration: Sericitic, potassic, and chloritic alteration is present (Wells and others, 1986).

Commodities (Major) - Cu, Mo; (Minor) - Au, Pb, W, Zn
Development Status: No
Deposit Model: Porphyry Mo (Cox and Singer, 1986; model 21b)

Other Databases

Link to USGS - Alaska:	TR006

Other Regions, Features and Areas containing this locality

References