Nortz

Prospect, Active

Commodities and mineralogy

Geographic location

Quadrangle map, 1:250,000-scale CA
Quadrangle map, 1:63,360-scale C-5
Latitude 65.5318
Longitude -161.4002
Nearby scientific data Find additional scientific data near this location
Location and accuracy This records includes several prospects exposed in outcrops for about a mile and a half along the west side of the south fork of upper Quartz Creek. The center of these occurrences is about 0.5 mile east of the center of section 32, T. 2 N., R. 13 W., of the Kateel River Meridian. The location is accurate.

Geologic setting

Geologic description

Many of the outcrops for about a mile and a half along the west side of the south fork of upper Quartz Creek are mineralized. This mineralization was first recognized by Miller and Elliott (1969) who sampled many of the outcrops. Some of their higher grade samples contained: 1) 7 parts per million (ppm) silver, 1 percent arsenic, 500 ppm copper, 1 percent lead, and 200 ppm zinc; 2) 7 ppm silver, greater than 1 percent arsenic, 150 ppm copper, 0.7 percent lead, and 700 ppm zinc; 3) 50 ppm silver, 2,000 ppm copper, greater than 2 percent lead, and greater than 1 percent lead; 4) up to 200 ppm silver, up to 1,000 ppm copper, greater than 2 percent lead, and greater than 1 percent zinc; 5) 150 ppm silver, 700 ppm copper, 15 ppm molybdenum, greater than 2 percent lead, and greater than 1 percent zinc.
The Nortz prospect is near the border of the mid-Cretaceous Quartz Creek pluton, a hook-shaped, quartz monzonite body at least 16 miles long and up to a mile wide. The pluton is surrounded by an alteration zone 2 to 5 miles wide that is marked by numerous mineral occurrences along the entire length of the pluton. The alteration zone is in Jurassic-Cretaceous andesitic volcanic and sedimentary rocks. Fine-grained dikes of varying composition cut the andesite and sedimentary rocks near the pluton.
The mineralization along Quartz Creek was examined by numerous geologists after its discovery and in 2005 the Linus Gold Corp. began work in the area. By 2006 they had staked 176 Alaska (state) claims that covered this prospect and others along the 'Kiwalik trend' of mineralization that roughly coincides with the Quartz Creek pluton and its alteration zone (Adams, 2007). They drilled several of the prospects along the belt to the south (see CA011, CA051, and CA052) and briefly examined the Nortz prospect at the north end of their claims and collected one sample. They describe the rocks as hornfelsed, highly sheared, highly mineralized, mafic volcanic rocks that are characterized by phyllitic alteration and tourmalinization. The rocks contain zones with abundant veins and stockworks that contain pyrite, calcite, quartz, arsenopyrite, stibnite, and galena. The sample contained 325 parts per billion gold, 34.5 ppm silver, 16,450 ppm lead, 449 ppm antimony, 872 ppm copper, and 4,345 ppm zinc.
Although Linus only briefly described this prospect, it is undoubtedly similar to the others to the south along the Kiwalik trend. Adams (2007) defines several types of mineralization along the belt, many occurring together: 1) sulfide-tourmaline-quartz veins with galena, sphalerite, and pyrite and locally minor arsenopyrite, pyrrhotite, chalcopyrite, and molybdenite; 2) disseminated pyrite and arsenopyrite in hairline veinlets that also locally contain sparse galena, stibnite, and bismuthinite; 3) sulfide-rich veins and veinlets with various assemblages of pyrite, pyrrhotite, chalcopyrite, arsenopyrite, sphalerite, galena, stibnite, molybdenite, and pyrargyrite, 4) pyrite-chlorite-calcite-quartz veins, 5) sulfide-quartz veins and stockworks with pyrite, pyrrhotite, arsenopyrite, galena, stibnite, sphalerite, chalcopyrite, and scheelite, and 6) fluorite-molybdenite-galena-pyrite-uranothorianite veinlets and disseminations. There are several distinct types of alteration associated with the mineralization: 1) phyllitic, 2) silicification, 3) carbonate, 4) argillic, 5) propylitic, 6) tourmalinization, 7) alunitic, and 8) potassic. Gossans with remnant galena and sphalerite are found locally.
Geologic map unit (-161.402848624755, 65.5311268296043)
Mineral deposit model Disseminated and veined, Ag-As-Au-Bi-Cu-Mo-Pb-Sb-Th-U mineralization in several styles that occurs widely for 16 miles along the altered border zone of a Cretaceous quartz monzonite.
Age of mineralization In the alteration zone of a Late Cretaceous quartz monzonite pluton.
Alteration of deposit Phyllitic alteration and tourmalinization of the mafic volcanic host rocks.

Production and reserves

Workings or exploration The prospect was discovered by the U.S. Geological Survey in 1969 and examined by numerous private geologists in succeeding years. In 2005, Linus Gold Corp. began work in the area and by 2006 had staked 176 Alaska claims that covered this prospect and others along the 'Kiwalik trend' that roughly coincides with the Quartz Creek pluton and its alteration zone. They drilled several of the prospects to the south along the Kiwalik trend and visited and sampled this prospect.
Indication of production None

References