No Grub Creek

Mine, Active

Commodities and mineralogy

Main commodities Au
Other commodities Bi; W
Ore minerals bismuth; gold; scheelite
Gangue minerals graphite; quartz

Geographic location

Quadrangle map, 1:250,000-scale BD
Quadrangle map, 1:63,360-scale C-4
Latitude 64.676
Longitude -145.611
Nearby scientific data Find additional scientific data near this location
Location and accuracy No Grub Creek is roughly 2 miles long and drains south into the Salcha River at the town of Caribou. The Alaska Division of Mining Kardex file system reports placer mining 1 mile along the base of No Grub Creek. The approximate center of the mining activity is in NW1/4NE1/4 section 7, T. 3 S., R. 11 E., of the Fairbanks Meridian. A tractor trail from the town of Caribou, and the Salcha River provide access to the lower No Grub Creek drainage. An airstrip on the Salcha River, shown on U.S.G.S. maps, is washed out and unsuitable for use (M.B. Werdon, oral communication, 1998). It is locality 17 of Cobb and Eberlein (1980), who summarized relevant references under the name 'No Grub Creek'.

Geologic setting

Geologic description

The bedrock in the region is schist, gneiss, some granite, and minor amounts of serpentinite and marble. The schist is composed of quartz, feldspar, and mica, with localized garnetiferous and marble zones. The gneiss is coarse to fine grained with various amounts of quartz, feldspar, hornblende, and biotite. They have suspected protoliths of Precambrian and Paleozoic sedimentary and igneous rocks. The intrusive bodies in the area range in composition from granodiorite to quartz monzonite with Cretaceous to Tertiary K-Ar ages (Weber and others, 1978). The intrusive bodies in the area range in composition from granodiorite to quartz monzonite with Cretaceous to Tertiary K-Ar ages (Weber and others, 1978). The gravels in the region average 18 to 20 feet in thickness and contain a variety of schist, gneiss, granite, and vein quartz (Prindle, 1906). Brooks (1908) reported the fineness of the gold in the Salcha region to be higher than that mined in the Richardson district.
It is reported that coarse gold, native bismuth, and minor scheelite were found in quartz veins in the No Grub Creek drainage (Menzie and Foster, 1979). Joesting (1942) noted an assay of gold and bismuth reported by C.F. Shield in 1938. Hasler and others (1973) report igneous and metamorphic hosted quartz veins containing variable amounts of native bismuth, bismuthinite, gold, graphite, and scheelite in the No Grub Creek drainage. Glover (1950) reported a range in gold fineness of 868 to 878 for No Grub Creek.
Placer gold was first discovered in the Salcha River area in 1905. Prospecting initially occurred on the Butte Creek (BD006) and soon extended to nearby Caribou Creek (BD009), Pasco Creek (BD031), and Gold Creek (BD015) and associated tributaries. Live water and thawed ground presented the biggest obstacles during prospecting (Prindle, 1906; B 284). No Grub Creek was reported as a major regional producer through 1915 (Brooks ,1916). Smith (1942) reported that No Grub Creek was mined using methods other than dredging. The property was mined hydraulically in the late 1930s and early 1940s (C.F. Shield, unpublished data, 1979). Eberlein and others (1977) report intermittent mining continued through the late 1970s. In 1997 and 1998, there was small-scale placer mining and prospecting along No Grub Creek (M.B. Werdon, oral communication, 1998). Exploration to determine the lode source for the placer gold is currently being conducted in the No Grub Creek drainage (R. Van Nieuwenhuyse, oral communication, 1998).
Historically, No Grub Creek placer has been grouped with the mines and prospects of the Richardson district. From 1905 through 1921, gold production for the Richardson district was approximately 95,000 ounces of gold and 24,000 ounces of silver (Bundtzen and Reger, 1977). During the late 1930s and early 1940s, values for two years of gold production on No Grub Creek were $43,000 and $100,000. But only 1,000 troy ounces of gold were recovered during a third year, and the operation was shut down (C.F. Shield, unpublished data, 1979).
Geologic map unit (-145.613392837543, 64.6756073855514)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a

Production and reserves

Workings or exploration Placer gold was first discovered in the Salcha River area in 1905. Prospecting initially occurred on Butte Creek (BD006) and soon extended to nearby Caribou Creek (BD009), Pasco Creek (BD031), and Gold Creek (BD015) and associated tributaries. Live water and thawed ground presented the biggest obstacles during prospecting (Prindle, 1906; B 284). No Grub Creek was reported as a major regional producer through 1915 (Brooks, 1916). Smith (1942) reported No Grub Creek was mined using methods other than dredging. The property was mined hydraulically in the late 1930s and early 1940s (C.F. Shield, unpublished data, 1979). Eberlein and others (1977) report intermittent mining through the late 1970s. Exploration to determine the lode source for the placer gold is currently being conducted in the No Grub Creek drainage (R. Van Nieuwenhuyse, oral communication, 1998).
Indication of production Yes; small
Production notes Historically, No Grub Creek placer has been grouped with the mines and prospects of the Richardson district. From 1905 through 1921, gold production for the Richardson district was approximately 95,000 ounces of gold and 24,000 ounces of silver (Bundtzen and Reger, 1977). During the late 1930s and early 1940s, values for two years of gold production were $43,000 and $100,000. But only 1,000 troy ounces of gold were recovered during a third year, and the operation was shut down (C.F. Shield, unpublished data, 1979).

References