Tozimoran Creek

Mine, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Sn
Ore minerals cassiterite; gold

Geographic location

Quadrangle map, 1:250,000-scale TN
Quadrangle map, 1:63,360-scale B-6
Latitude 65.37922
Longitude -152.78918
Nearby scientific data Find additional scientific data near this location
Location and accuracy This placer mine is in the headwaters of Tozimoran Creek, which drains the northeast side of Moran Dome. The mine is in the northwest quarter of section 6, T. 6 N., R. 25 W., of the Fairbanks Meridian. It is approximately one quarter of a mile above the confluence with Chicken Creek, and 4 miles east of Moran Dome. The location is accurate within 2,000 feet. The site corresponds to location 16 of Cobb (1972), and roughly to Tozimoran Creek, U.S. Bureau of Land Management MAS number 0020480011.

Geologic setting

Geologic description

Bedrock in the Tozimoran Creek area consists of metamorphosed sedimentary rocks and mafic igneous rocks (Chapman and others, 1963). The local bedrock is mainly quartz-mica schist. Coarsely crystalline to porphyritic Cretaceous granite, cut by small granitic dikes, crops out about 5 miles north and west of the Tozimoran Creek mine (Chapman and others, 1982).
The deposit consists of a bench placer on the north side of Tozimoran Creek, and of alluvium in the present stream channel, 2,000 feet downstream from the mouth of Ash Creek (TN020) (Thomas and Wright, 1948 [RI 4323]). Both bench and stream gravels are approximately 4 feet thick, and the bench also contains 3 feet of muck, frozen in many places. Gold, along with cassiterite, is concentrated in the bottom 2 feet of the bench gravels and is evenly distributed throughout the stream gravels.
The gold and cassiterite do not appear to penetrate bedrock beyond 6 inches (Thomas and Wright, 1948 [RI 4323]). The cassiterite occurs as subangular to angular grains, pebbles, and cobbles up to three pounds; it is dark brown to black and translucent to opaque. The companion gold is clean and subangular, with reported fineness of 835 to 895 (Chapman and others, 1963).
Little mining and prospecting has actually been done on Tozimoran Creek, where gold was discovered in 1902 (Thomas and Wright, 1948 [RI 4323]). Early reports of mining in Columbe Creek, Moraine Creek, and Moran Creek (Brooks, 1908; Smith, 1932, 1933, 1936, 1937) likely refer to Tozimoran Creek (Cobb, 1977). There are no records of large-scale mining in the 1930s, only of sporadic prospecting. I.W. Purkeypile and Martin Webories hand-mined the upper portion of Tozimoran Creek from 1938 until at least 1944 (Thomas and Wright, 1948 [RI 4323]). Wright (1940) examined the property and concluded that the gold and cassiterite pay streaks were not continuous or rich enough to warrant mining. The U.S. Bureau of Mines examined the Tozimoran Creek area in 1944. The results of some of their channel sampling from the bench placer indicated an average of 0.731 pound of tin and 0.0228 ounce of gold per cubic yard in a block 650 feet long and 80 feet wide (Thomas and Wright, 1948 [RI 4323]). Purkeypile and Webories maintained active claims through at least 1967 (Heiner and others, 1968). The only reported recent activity was by Wayne Gibson, who mined placer cassiterite in the 1980s (Bundtzen and others, 1986).
Wedow and others (1952) reported silver-lead ore in the headwaters of Tozimoran Creek (TN021), where galena occurs in quartz-calcite stringers and veins that cut the quartz-mica schist. There is no cassiterite in the gravels near these veins.
Geologic map unit (-152.791715724933, 65.3786871773763)
Mineral deposit model Placer Au(-Sn) (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary.

Production and reserves

Workings or exploration Only a small amount of work has been done on Tozimoran Creek. Smith (1942) reported prospecting in 1940. I.W. Purkeypile and Martin Webories hand-mined the upper portion of Tozimoran Creek from 1938 until at least 1944 (Thomas and Wright, 1948 [RI 4323]). Later reports indicate that some prospecting was done in 1942 (Thomas and Wright, 1948 [RI 4323]) and again in 1952 (Chapman and others, 1963). Purkeypile and Webories maintained active claims through at least 1967 (Heiner and others, 1968). Wayne Gibson mined placer deposits of cassiterite in the area in 1985 (Bundtzen and others, 1986). Cusac Gold Mines announced that they intended to explore in the vicinity of Moran Dome during the 2000 field season (Cusac Gold Mines, Ltd., press release, October 20,1999).
Indication of production Yes; small
Production notes Production of placer gold from Tozimoran Creek has not been made public. In 1977, Cobb (1977) echoed the estimate by Thomas and Wright (1948 [RI 4323]), suggesting that production was probably was little more than a few ounces of gold and a few hundred pounds of cassiterite concentrate.

References

MRDS Number A015189

References

Heiner, L.E., Wolff, E.N., and Lu, F.C.J., 1968, Mining regions and mineral commodities, in Heiner, L.E., and Wolff, E.N. eds., Final Report - Mineral Resources of Northern Alaska: Mineral Industry Research Laboratory, University of Alaska Report No. 16, p. 3-137.
Reporters G.E. Graham (ADGGS), D.J. Szumigala (ADGGS)
Last report date 7/21/2003