McKinley Creek Falls

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Au; Zn
Ore minerals gold; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SK
Quadrangle map, 1:63,360-scale B-4
Latitude 59.37
Longitude -136.23
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of approximately 1,600 feet near the base of a falls in the steep-walled canyon of McKinley Creek . It is on the eastern edge of the NE1/4, section 12, T. 29 S., R. 54 E. of the Copper River Meridian. It is shown as location 20 by Still and others (1991).

Geologic setting

Geologic description

The rocks in the area consist of slate with interbedded limestone that is cut by altered, tan dikes. Narrow, discontinuous quartz-sphalerite veins or silicified bands are in the dikes and, to a lesser extent, in the slate and limestone. Selected high-grade samples of quartz-sphalerite veins in dikes, contained up to 13.4% zinc and 8.9 ppm gold. A 2.5-foot-long chip sample across a limy silicified band in limy slate contained 24.8 ppm gold and 280 ppm zinc (Gilbert and others, 1991; Still and others, 1991).
This prospect is similar to the Golden Eagle prospect (SK047). It occurs within a northwest-trending zone of quartz-sulfide veining in sediments and slates in the Skagway B-4 quadrangle that is described by Wright (1904 [B 225 and B 236]), Eakin (1918 and 1919), and MacKevett and others (1974) and is considered to be the source of placer gold in this area.
Geologic map unit (-136.231858850055, 59.3696680394968)
Mineral deposit model There is little information but the brief description by Still and others (1991) who refer to polymetallic veins in dikes and replacement mineralization in adjacent limy sediments (Cox and Singer, 1986; models 22c and 19a).
Mineral deposit model number 22c and 19a
Age of mineralization Unknown, but probably Cretaceous or younger based on age of intrusives in area (MacKevett and others, 1974).
Alteration of deposit Silica-carbonate units which are cut by or parallel the quartz-sulfide veins are probably altered mafic dikes (Still and others, 1991). Questionable mariposite may be due to alteration of mafic minerals (Bundtzen and Clautice, 1986).

Production and reserves

Indication of production None

References

MRDS Number 10308250

References

Gilbert and Redman, 1989;
Reporters T.C. Crafford (T. Crafford & Associates, Anchorage)
Last report date 2/4/2001