Molly Creek

Prospect, Probably inactive

Alternative names

My Creek

Commodities and mineralogy

Main commodities Sb
Other commodities Ag; Au
Ore minerals gold; orpiment; realgar; stibnite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale EA
Quadrangle map, 1:63,360-scale A-5
Latitude 64.1017
Longitude -143.3022
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Molly Creek prospect is located in a saddle on the ridge between Our and My Creeks. The center of the prospect is in the SW1/4 section 20, T. 27 N., R. 11 E., of the Copper River Meridian. The location is accurate. The Molly Creek prospect is locality 8 of Cobb (1972 (MF-393) and locality 42 of Eberlein and others (1977). The Molly Creek prospect is located within Doyon, Ltd. selected or conveyed land.

Geologic setting

Geologic description

The Molly Creek prospect is in Paleozoic gneiss, schist, quartzite, and marble that have been intruded by the Mount Veta syenite of Jurassic age (Foster, 1976). Other Tertiary to Mesozoic monzonite and granite intrusions are located about 1 mile east of the prospect, and there are felsic and mafic dikes in the area (Dashevsky and others, 1986). The granitic intrusion to the east is epidotized and contains local altered zones near the contact (Foster and Clark, 1970). Several other prospects are spatially associated with the Mount Veta intrusive complex, including East Eva (EA098), Oscar (EA096), Oscar West (EA097), Little Enchilada (EA103), Unnamed (north of Fish Creek) (EA062), Eva Creek (EA099), Little Whiteman Creek (EA060), and Mitchell (EA101).
The Molly Creek prospect consists of an east-dipping, northeast-striking quartz vein system with marble clasts that contain bladed stibnite along drusy vein walls. Trenches have been dug across 610 meters of the vein system. Stibnite in the trenches occurs as veinlets, blebs, and large radiating crystal masses in limonite-stained quartzitic and quartz-carbonate breccia; orpiment, realgar, and rare traces of gold also occur (Dashevsky and others, 1986). Rubble of a massive, milky quartz vein about 4 feet wide and silicified marble is exposed in several trenches. The vein follows the contact between footwall quartzo-feldspathic schist and hanging-wall marble. The footwall contact of the vein is sharp, and mineralization and alteration do not extend into the adjacent schist. On the hanging wall, marble grades into silicified marble and quartz veining; silica flooding of the marble has produced 'sponge' rock (U.S. Bureau of Mines, 1995). This marble contains trace stibnite; drilling indicates the marble horizon may be as thick as 18 meters.
Seven short Winkie drill holes at various angles from the same location link the antimony mineralization to a fault-controlled silica-carbonate zone. There are local mineralized shoots on cross faults displacing the main structure (Dashevsky and others, 1986). Average grades in drill holes were under 0.5 percent antimony. Ore samples contain as much as 49 percent antimony; the highest gold value was 0.007 ounce of gold per ton. An eighth hole stepped out 700 feet along strike and cut 11 feet with more than 2 percent antimony. Two samples from the trenches contain as much as 37.7 percent antimony, and a sample of boxworks gossan contains 0.24 ounce of silver per ton (U.S. Bureau of Mines, 1995). There are gold anomalies of as much as 1,955 ppb gold in streams draining the prospect (WGM Inc., 2000 [Veta property summary]). The silver and antimony soil anomalies at the prospect continue beyond the sampling, and the mineralization may extend 3 miles along the structural zone.
The deposit was discovered in 1918 by following a 1,500 foot-long float train of stibnite in tundra (WGM Inc., 1998 [DLR 98-10]). About 4 tons of high-grade ore, estimated to contain more than 50 percent antimony, and several tons of lower grade ore were found in overburden during trenching that followed (Joesting and Anderson, 1942). The U.S. Bureau of Mines explored the prospect with a churn drill in 1943; stibnite was found in only one of the seven short holes that were drilled (Ebbley and Wright, 1948). Apex Exploration sampled soil on a grid in 1973 and did 4,000 feet of trenching at the prospect in 1974 (Dashevsky and others, 1986). Eight short Winkie holes were drilled and trench mapping was done by Consolidated Durham Mines in 1975; the average grade of the antimony found to be low and the stibnite shoots small (Dimarchi and others, 1990). Placid Oil Company remapped the prospect in 1976; they sampled soil on a grid and conducted a VLF-EM geophysics survey in 1977. In 1981, Arctic Resources Inc. briefly examined the trenches, and in 1982, Doyon,Ltd. surveyed the trenches, inventoried the core, and carried out magnetic and IP surveys. WGM Inc. conducted a soil sampling program in 2001 and identified a 5,800-foot-long antimony soil anomaly (Ventures Resource Corp., 2002).
Geologic map unit (-143.304491241181, 64.1013486048751)
Mineral deposit model Simple Sb deposit (Cox and Singer, 1986; model 27d).
Mineral deposit model number 27d
Age of mineralization Probably related to the Mount Veta syenite of Jurassic age.

Production and reserves

Workings or exploration The deposit was discovered in 1918 by following a 1,500 foot-long float train of stibnite in tundra (WGM Inc., 1998 [DLR 98-10]). About 4 tons of high-grade ore, estimated to contain more than 50 percent antimony, and several tons of lower grade ore were found in overburden during trenching that followed (Joesting and Anderson, 1942). The U.S. Bureau of Mines explored the prospect with a churn drill in 1943; stibnite was found in only one of the seven short holes that were drilled (Ebbley and Wright, 1948). Apex Exploration sampled soil on a grid in 1973 and did 4,000 feet of trenching at the prospect in 1974 (Dashevsky and others, 1986). Eight short Winkie holes were drilled and trench mapping was done by Consolidated Durham Mines in 1975; the average grade of the antimony found to be low and the stibnite shoots small (Dimarchi and others, 1990b). Placid Oil Company remapped the prospect in 1976; they sampled soil on a grid and conducted a VLF-EM geophysics survey in 1977. In 1981, Arctic Resources Inc. briefly examined the trenches, and in 1982, Doyon, Ltd. surveyed the trenches, inventoried the core, and carried out magnetic and IP surveys. WGM Inc. conducted a soil sampling program in 2001 and identified a 5,800-foot-long antimony soil anomaly (Ventures Resource Corp., 2002).
Indication of production Yes; small
Production notes About 4 tons of high-grade ore, estimated to contain more than 50 percent antimony, and several tons of lower grade ore were found in overburden during trenching at the Molly Creek prospect (Joesting and Anderson, 1942).

Additional comments

The Molly Creek prospect is located within Doyon, Ltd. selected or conveyed land. For more information contact Doyon, Ltd., Fairbanks, Alaska.

References

References

Caithness Alaska Mining Co., 1990, 1989 annual report, Alaska field operations, appendix 7.2.1A, Doyon reconnaissance geochemical results, part A, volume 2 of 14: Doyon, Ltd. Report 90-06b, 149 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Caithness Alaska Mining Co., 1990, 1989 annual report, Alaska field operations, appendix 7.2.1A, Doyon reconnaissance geochemical results, part B, volume 3 of 14: Doyon, Ltd. Report 90-06c, 145 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Caithness Alaska Mining Co., 1990, 1989 annual report, Alaska field operations, appendix 7.2.1C, Doyon reconnaissance geochemical results, part C, appendix 7.2.2, rock sample descriptions and appendix 7.2.3, geochemical results, sample locations and descriptions - diskettes, volume 4of 14: Doyon, Ltd. Report 90-06d, 181 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Caithness Alaska Mining Co., 1990, 1989 annual report, Alaska field operations, volume 1 of 14: Doyon, Ltd. Report 90-06a, 251 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Carter, C.H., 1981, Doyon exploration program, Blocks 4, 5, 8, and 22: Doyon, Ltd. Report 81-27. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Dashevsky, S.S., 1983, Doyon exploration program, Block 8 - Fortymile, 1982: Doyon, Ltd. Report 83-01. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Dashevsky, S.S., 1984, Block 8 - Fortymile, summary of exploration activity of Placid Oil Company (1975-1978): Doyon, Ltd. Report 83-16. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Dashevsky, S.S., Nicol, D.L., and Bond, J., 1986, Mines, prospects, and geochemical anomalies on Doyon Limited regional overselection lands, Alaska, Blocks 1-8: Doyon, Ltd. Report 86-01a, 300 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).
DiMarchi, J.J., Flanders, R.W., Freeman, L.K., Puchner, C.K., Rohtert, W.R., Stubbs, G.S., and Tolbert, R.S., 1990 (1989), 1989 annual report, Alaska field operations, volume 1: Central Alaska Exploration Corporation, 203 p. (Report held by Doyon, Limited, Fairbanks, Alaska)
DiMarchi, J.J., Flanders, R.W., Freeman, L.K., Puchner, C.K., Rohtert, W.R., Stubbs, G.S., and Tolbert, R.S., 1990, 1989 annual report, Alaska field operations, volume 1: Central Alaska Exploration Corporation, Doyon, Ltd. Report 90-06j. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Sweet, K., 1982, Interpretation report of the geophysical surveys conducted on Block 8 and Block 20: Doyon, Ltd. Report 82-36. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Ventures Resource Corp., 2002, 2001 Annual report: Ventures Resource Corporation, 32 p.
WGM Inc., 1998, Veta property, 1997 annual report, volume 1: Doyon, Ltd. Report 98-10, 227 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).
WGM Inc., 2000, Veta property summary, in Ventures Resource Alaska project overview and properties summary: Ventures Resource Corporation report.
Reporters M.B. Werdon; R.L. Flynn; D.J. Szumigala
Last report date 4/4/2003