UPEG Saddle

Mine?, Undetermined

Alternative names

Hajdukovich

Commodities and mineralogy

Main commodities Ag; As; Au; Bi; Cu; Pb; Sb
Ore minerals arsenopyrite; gold; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale C-3
Latitude 63.5773
Longitude -145.0557
Nearby scientific data Find additional scientific data near this location
Location and accuracy The UPEG Saddle prospect is about a mile northwest of peak 7837 and about 5.6 miles northeast of Mount Hajdukovich. It is near the northwest corner of section 33, T. 21 N., R. 13 E. The location is accurate. A map of the UPEG Saddle prospect is figure 11 of Freeman (2009).

Geologic setting

Geologic description

The Upeg Saddle and other prospects of the Hajdukovich project were first identified by Teck-Cominco from 1999 to 2001 through regional geochemical sampling followed by mapping and sampling in the steep terrain in the headwaters and east of the Little Gerstle River (Freeman, 2009). The area was dormant from 2002 to 2004. In 2005, Canaco Resources optioned the property and drilled 3 holes at the nearby Sneaker prospect (MH366). They terminated their option in 2006 and the property reverted to Teck-Cominco. Teck-Cominco abandoned the property in 2008. A contiguous block of 49 State of Alaska claims was staked by Anglo Alaska Gold Corp. that covered almost all of the original Teck-Cominco and Canaco prospects. These claims were current as of 2009 and constitute the Hajdukovich project.
The geology of the area is dominated by a Paleocene multiphase, composite intrusive complex about 5 by 15 kilometers in size (Nokleberg and others, 1992; Freeman, 2009). The main rocks in the complex are mafic and ultramafic intrusive rocks, diorite and monzonite, alkali feldspar granite, and megacrystic granite; these are cut by a variety of aplite, rhyodacite, rhyolite, and basalt dikes. The intrusive rocks cut metamorphic rocks of the Jarvis Creek unit, which consists mainly of pelitic schist, gneiss, and quartzite. The Jarvis Creek unit is metamorphosed to greenschist facies north of the complex and to amphibolite(?) facies south of it. The structure of the area is dominated by steep northeast- and northwest-trending faults that range from the regional to the prospect-level scale. Six distinctive but related styles of mineralization have been identified in the Hajdukovich project area: 1) low sulfide, gold-quartz veins; 2) gold-sulfide-carbonate-quartz veins and veinlets; 3) sulfide-quartz veinlets; 4) gold-PGE-bearing chalcopyrite-magnetite pods and veins; 5) gold-bearing sulfide-quartz breccias; and 6) gold-bearing semi-massive sulfides.
Several types of mineralization are at the UPEG Saddle prospect (Freeman, 2009). Pods of massive stibnite are exposed in old prospect pits and trenches along the ridge. Although, there apparently is no previous record of the massive stibnite here, Freeman (2009) suggests that it was mined in the 1940s as part of the war effort. Several samples were analyzed; none contained anomalous gold. South of the stibnite occurrence, east-trending aplite dikes cut porphyritic alkali-feldspar granite. The dikes are cut by arsenopyrite-quartz veins; samples contained up to 5,900 parts per billion (ppb) gold, 2.6 parts per million (ppm) silver, 64 ppm lead, and 327 ppm antimony. Still farther south, disseminated porphyry-style, copper-gold mineralization is in potassic-altered trachytic and porphyritic alkali-feldspar granite. Samples contained up to 6,850 ppb gold, 75.2 ppm silver, 4,230 ppm copper, and have anomalous amounts of bismuth, lead, and antimony. The mineralized alkali-feldspar granite is cut in several places by quartz veins containing pyrite, arsenopyrite, and stibnite. The numerous samples from the UPEG Saddle prospect contained up to 6,850 ppb gold, more than 1 percent arsenic, 20,500 ppm copper, 2,090 ppm lead, 2,680 ppm antimony, and 584 ppm bismuth. Other than the old pits and trenches, there has been only surface sampling at this prospect.
Geologic map unit (-145.057967486782, 63.5769139586489)
Mineral deposit model Polymetallic gold-quartz veins (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Paleocene or younger based on the age of the host rock.
Alteration of deposit Potassic alteration of trachytic and porphyritic alkali-feldspar granite associated with porphyry-style mineralization.

Production and reserves

Workings or exploration This and the other prospects of the Hajdukovich project were first identified by Teck-Cominco from 1999 to 2001 through regional geochemical sampling followed by mapping and sampling in the steep terrain in the headwaters and east of the Little Gerstle River (Freeman, 2009). The area was dormant from 2002 to 2004. In 2005, Canaco Resources optioned the property and drilled 3 holes at the nearby Sneaker prospect (MH366). They terminated their option in 2006 and the property reverted to Teck-Cominco. Teck-Cominco abandoned the property in 2008. A contiguous block of 49 State of Alaska claims was staked by Anglo Alaska Gold Corp. that covered almost all of the original Teck-Cominco prospects. Since the late 1990s, there has been only surface sampling at this prospect. However there are old prospect pits and trenches from which stibnite may have been mined during WWII.
Indication of production None
Reserve estimates None.
Production notes Some stibnite may have been mined during the 1940s.

References

References

Freeman, C.J., 2006, Executive summary report for the Hadukovich gold project, Delta River mining district, Alaska: Unpublished report for Canaco Resources Inc., 70 p. (posted on www.sedar.com, June 9, 2006).
Freeman, C.J., 2009, Geology and mineralization of the Hajdukovich gold project, Delta River mining district, Alaska: Unpublished report for Anglo- Alaska Gold Corp, 68 p. (as of Feb 10, 2011, on web at http://www.avalonalaska.com/Project_of_Month/HA-10EXE1-Form43.pdf)
Reporters D.J. Grybeck (Contractor, USGS)
Last report date 2/28/2011