Unnamed (on west side of Little Jarvis Glacier)

Prospect, Active

Commodities and mineralogy

Main commodities Ag; Au; Ba; Cu; Pb; Zn
Ore minerals barite; galena; pyrite; sphalerite

Geographic location

Quadrangle map, 1:250,000-scale SK
Quadrangle map, 1:63,360-scale B-4
Latitude 59.4095
Longitude -136.4258
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is about 3 miles northeast of the summit of Mt. Henry Clay at an elevation of approximately 3,500 feet. It is near the southeast corner of section 29, T. 28 S., R. 53 E. Still and others (1991) informally named this the Little Jarvis prospect For this record, it is not named to distinguish it from the better known prospect of that name to the southeast on the other side of the Little Jarvis Glacier (SK067).

Geologic setting

Geologic description

Still and others (1991) describe this prospect as small discontinuous sulfide bands in metasedimentary and metavolcanic rocks. Their samples contained up to 0.345 parts per million (ppm) gold, 11.8 ppm silver, 13.6 percent zinc, 1,900 ppm copper, 3.8 percent lead, 1.44 percent barium, and 2,000 ppm arsenic. This prospect is not specifically mentioned in Greig and Giroux (2010). However, it is at the southeast end of a 3-mile-long line of massive sulfide occurrences and they suggest that all of the volcanic massive sulfide deposits in this area are related, if they were not originally continuous.
The rocks in the region are part of the Upper Triassic Hyd Group that hosts similar volcanic massive sulfide deposits the length of southeastern Alaska (Newberry and others, 1997). The rocks are predominantly massive and pillow basalts and fragmental basalt and andesite(?), intercalated with siltston, tuff, and rare rhyolite flows and dikes. They have been subject to greenschist-facies metamorphism; folding and faulting locally repeats the stratigraphy in places, and the rocks are highly altered.
There have been several published studies of the mineral deposits in the area by government and academe (MacKevett and others, 1974; Still, 1984, Still and others, 1991; Newberry and others, 1997; Greig and Giroux, 2010) and unpublished studies by industry. The consensus from early on was that the they are Late Triassic, stratiform volcanogenic massive-sulfide deposits.
Geologic map unit (-136.427665564417, 59.4091631473163)
Mineral deposit model Probably a Besshi- or Kuroko-type volcanogenic massive sulfide (Cox and Singer, 1986; models 28a or 24b).
Mineral deposit model number 28a or 24b
Age of mineralization Late Triassic by analogy with other similar deposits of that age along the length of southeastern Alaska and into Canada.

Production and reserves

Workings or exploration The only published record of work at this prospect was sampling by Still (1991). However, it is in a large block of claims in an area that has been intensely explored by government and industry for several decades (Greig and Giroux, 2010).
Indication of production None
Reserve estimates None.
Production notes None.

References

MRDS Number 10308257

References

Greig, C.J., and Giroux, G.H., 2010, Palmer VMS project, southeast Alaska; Mineral resource estimation and exploration update: Technical l report for Constantine Metal Resources Ltd. 82 p. (posted on www.sedar.com, Mar. 8, 2010).
Newberry, R.J., Crafford, T.C., Newkirk, S.R., Young, L.E., Nelson, S.W., and Duke, N.A., 1997, Volcanogenic massive sulfide deposits of Alaska, in Goldfarb, R.J. and Miller, L. D., eds., Mineral deposits of Alaska: Economic Geology Monograph 9, p. 120-150.
Rubicon Minerals, 1998, Palmer VMS Project, southeast Alaska, Executive Summary: Unpublished report by Rubicon Minerals Corporation, Vancouver, British Columbia, 25 p.
Rubicon Minerals, 1999, Press releases from 1999 drill exploration program: Internet site of Rubicon Minerals Corporation, Vancouver, British Columbia (http://www.rubiconminerals.com)
Reporters T.C. Crafford (T. Crafford & Associates, Anchorage); D.J. Grybeck (Contractor, USGS)
Last report date 2/28/2011