|Quadrangle map, 1:250,000-scale||SK|
|Quadrangle map, 1:63,360-scale||B-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is at the head of Porcupine Creek in prominent cliff exposures between the elevations of 3,600 and 5,400 feet on the northwest side of Peak 5420. It was informally termed the 'Quartz Swarm' prospect by Still and others (1991).|
According to Still and others (1991), this prospect was discovered by Merril Palmer in 1984. It consists of swarms of quartz veins in slate and metabasalt exposed in prominent cliffs that (like SK052) appear to be in a roof pendant surrounded by diorite. The veins average about 0.5 to 1.5 feet thick and extend for hundreds of feet along strike. The vein swarms are many hundreds of feet across and extend for more than a thousand feet vertically. Sixty samples were collected from the veins and surrounding wall rocks. Gold values were generally low; 6 samples, mostly of quartz veins, contained 0.005 to 0.09 ppm gold. The 60 samples also contained up to 2.4 ppm silver, 390 ppm zinc, 150 ppm copper, 3,000 ppm barium, 700 ppm arsenic, 200 ppm nickel, and 3,000 ppm antimony. Samples collected through 1,500 feet of elevation and 4,000 feet across structure showed no potentially economic gold values.The sedimentary and basaltic protoliths to the slate and metabasalt are Paleozoic in age. The veins and mineralization are probably Cretaceous or younger in age, based on their probable genetic relationship to the surrounding diorite (MacKevett and others, 1974).
|Geologic map unit||(-136.311869768907, 59.3096523724909)|
|Mineral deposit model||Based on limited information, these are probably polymetallic quartz veins (Cox and Singer, 1986; model 22c).|
|Mineral deposit model number||22c|
|Age of mineralization||Probably Cretaceous or younger based on the age of the surrounding diorite (MacKevett and others, 1974).|
|Workings or exploration||Discovered by Merrill Palmer in 1984.|
|Indication of production||None|
MacKevett, E.M., Jr., Robertson, E.C., and Winkler, G.R., 1974, Geology of the Skagway B-3 and B-4 quadrangles, southern Alaska: U.S. Geological Survey Professional Paper 832, 33 p., 1 plate.
Still, J.C., 1991, Section A: Haines - Klukwan - Porcupine subarea, in U.S. Bureau of Mines, Mineral investigations in the Juneau Mining District, Alaska, 1984-1988: Volume 2 - Detailed mine, prospect, and mineral occurrence descriptions: U.S. Bureau of Mines Special Publication VOL. 2A, 214 p., 9 sheets.
Still, J.C., Hoekzema, R.B., Bundtzen, T.K., Gilbert, W.G., Wier, K.R., Burns, L.E., and Fechner, S.A., 1991, Economic geology of Haines-Klukwan-Porcupine area, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 91-4, 156 p., 5 sheets, scale 1:63,360.
|Reporters||T.C. Crafford (T. Crafford & Associates, Anchorage)|
|Last report date||2/4/2001|