Unnamed (south of VABM Flat)

Occurrences, Inactive

Commodities and mineralogy

Main commodities Au; Cu
Other commodities As; Mo; Pb; Sb; W
Ore minerals malachite

Geographic location

Quadrangle map, 1:250,000-scale MZ
Quadrangle map, 1:63,360-scale C-2
Latitude 65.6609
Longitude -153.9841
Nearby scientific data Find additional scientific data near this location
Location and accuracy Several occurrences of iron-stained felsic intrusive rock are on a half-mile-long section of ridge due south of hill 3214 (VABM Flat). The site corresponds to ADGGS station 92DNS158 (Solie and others, 1993 [Public-Data File 93-33]). It is at an elevation of 1,700 feet, 0.2 mile southeast of the center of section 13, T. 3 N., R. 23 E., Kateel River Meridian. The location is accurate.

Geologic setting

Geologic description

The rocks in the vicinity of these occurrences are part of a northeast-trending stock about a mile wide of fine- to medium-grained hornblende-biotite granodiorite (Patton and others, 1977). Patton and others (1977) correlate the granodiorite with the Upper Cretaceous Dulbatna Mountain pluton, dated by K-Ar methods at 82.3 +/-3 Ma (biotite) and 90.0 +/3 Ma (hornblende). The granodiorite intrudes and thermally alters Lower Cretaceous quartz-pebble conglomerate and quartzose sandstone just south of the occurrences, and andesitic and dacitic tuff, agglomerate, breccia, and tuffaceous graywacke about 1 mile to the north.
The Alaska Division of Geological and Geophysical Surveys collected 4 samples along the crest of a short ridge south of VABM Flat. Two samples of iron-stained felsic intrusive rock with sparse malachite were analyzed (Solie and others, 1993 [Public-Data File 93-33]). They contained up to 121 parts per million (ppm) arsenic, 120 parts per billion (ppb) gold, 1,185 ppm copper, 56 ppm molybdenum, 186 ppm lead, 16 ppm antimony, 11 ppm tin, and 15 ppm tungsten.
Geologic map unit (-153.986691560751, 65.6603500402401)
Mineral deposit model Sn veins (Cox and Singer, 1986; model 15b), Porphyry Sn (Cox and Singer, 1986; model 20a), Sn-polymetallic veins (Cox and Singer, 1986; model 20b), Polymetallic veins (Cox and Singer, 1986; model 22c)
Mineral deposit model number 15b, 20a, 20b, 22c
Age of mineralization Upper Cretaceous or younger based on the age of the host rocks.
Alteration of deposit Country rocks are thermally metamorphosed.

Production and reserves

Workings or exploration Only limited sampling by the Alaska Division of Geological and Geophysical Surveys.
Indication of production None

References