|Quadrangle map, 1:250,000-scale||MH|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is northwest of the 1966 terminus of the Chistochina Glacier at an elevation of about 5,200 feet. The occurrence is in the SE1/4SE1/4 section 4, T. 20 S., R. 15 E., Fairbanks Meridian. It corresponds to locality 17 on figure 1 of Rose (1967)and locality 8 on figure 6 of Cobb (1979 [OFR 79-238]) and is approximately the same as locality 133 in table 2 of Nokleberg and others (1991). The location is accurate within 0.2 mile.|
The rocks in this area are part of the Eagle Creek Formation of Early Permian age and consist of interlayered argillite and limestone (Nokleberg and others, 1991). The unit was mapped as Mankomen Formation by Rose (1967). Subsequently, the units were remapped as part of the Eagle Creek Formation, a member of the Mankomen Group (Richter and Dutro, 1975).
The Eagle Creek argillite is extensively pyritized at the site. The pyritized argillite lies north of a body of Upper Triassic (?) ultramafic rock that is intruded by quartz monzonite of Mesozoic age (Rose, 1967).A grab sample of pyritic argillite contained 0.02 ounce of gold per ton and trace amounts of silver and zinc (Rose, 1967).
|Geologic map unit||(-144.873729926055, 63.2062047178684)|
|Age of mineralization||Post-Early Permian and probably Mesozoic, related to a nearby granodiorite intrusion.|
|Alteration of deposit||Pyritization of Lower Permian argillite.|
|Workings or exploration||Geologic mapping and limited surface sampling.|
|Indication of production||None|
Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Mount Hayes quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-238, 140 p.
Nokleberg, W.J., Lange, I.M., Roback, R.C., Yeend, Warren, and Silva, S.R., 1991, Map showing locations of metalliferous lode and placer mineral occurrences, mineral deposits, prospects, and mines, Mount Hayes quadrangle, eastern Alaska Range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1996-C, 42 p., 1 sheet, scale 1:250,000.
Richter, D.H., and Dutro, J.T., Jr., 1975, Revision of the type Mankomen Formation (Pennsylvanian and Permian), Eagle Creek area, eastern Alaska Range, Alaska: U.S. Geological Survey Bulletin 1395-B, p. B1-B25.
|Reporters||W.T. Ellis (Alaska Earth Sciences) and C.C Hawley (Hawley Resource Group)|
|Last report date||7/1/2003|