|Quadrangle map, 1:250,000-scale||UN|
|Quadrangle map, 1:63,360-scale||C-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Located approximately 2,500 m north of Makushin River on northernmost ridge between Broad and Wide Bays. Occurrence extends for at least 9,000 feet (2,800 m) in an east-west direction. Latitude and longitude is of central point of vein system.|
Geologic descriptionVery similar to Makushin Valley (UN009) vein; in particular the east-west trending part of the Makushin Valley vein system. Quartz veins occur in propylitically altered porphyritic andesite and andesitic volcaniclastic rocks of the Unalaska Formation (see Drewes and others, 1961). The Mak North vein system is intermittently exposed over a lateral distance of at least 9,000 feet (2,800 m) and a vertical distance of 1,000 feet (300 m). The veins are composed of massive, milky quartz that has been brecciated and then healed by multiple void-filling bands of cockscomb quartz. The Mak North vein system has a reported range in thickness from 2 to 20 feet (0.7 to 7 m).
|Geologic map unit||(-166.653690663721, 53.9415332477389)|
|Mineral deposit model||Epithermal gold vein|
|Mineral deposit model number||25|
|Age of mineralization||Late Tertiary or younger|
|Alteration of deposit||Regional propylitic alteration; no apparent wall-rock alteration around vein.|
|Workings or exploration||The main or 'discovery' zone was originally located from the air and was channel sampled using a line spacing of roughly 15 m. This sampling outlined a length of about 60 m having gold values averaging 0.024 oz/t (0.82 ppm), and having a highest value of 0.034 oz/t (1.17 ppm) over 7.5 m. Other sampling of the vein yielded gold values as high as 690 ppb. the veins have identical Au/Ag/Hg/As and base metal signatures as the east-west veins in the Makushin Valley (UN009) occurrence (Randolph, 1991).|
|Indication of production||None|
Additional commentsSee also UN009, UN011
Drewes, Harold, Fraser, G.D., Snyder, G.L., and Barnett, H.F., Jr., 1961, Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska: U.S. Geological Survey Bulletin 1028-S, p. 583-676.
Randolph, D.B., 1991, Unalaska project, 1990 final report: Battle Mountain Exploration Company, Alaska District, 62 p., 5 appendices, 15 plates, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
|Last report date||12/18/1992|