Lucky Shot; Willow Creek Mines Inc. Mine, Willow Creek District, Matanuska-Susitna Borough, Alaska, USA
|Latitude & Longitude (WGS84):||61° 46' 44'' North , 149° 24' 28'' West|
|Latitude & Longitude (decimal):||61.77889,-149.40778|
|Köppen climate type:||Dfc : Subarctic climate|
Location: The portal of the Lucky Shot mine is on the northwest valley wall of Craigie Creek, 1.8 miles northeast of the junction of Craigie Creek and Willow Creek. The mine is marked by symbol labeled 'Lucky Shot Mine' on the Anchorage D-7 1:63,360-scale topographic map. The underground workings extend for a considerable distance northwest from the portal. The adjacent War Baby mine (AN003) and the Lucky Shot mine were long ago consolidated into a single property which now is commonly referred to as the Lucky Shot.
Geology: Quartz veins cut quartz diorite of the Late Cretaceous Willow Creek Pluton, which is jointed and sheeted near the surface but less so underground. The pluton is zoned; the outer part consists of hornblende quartz diorite and lesser hornblende tonalite; the core consists of hornblende-biotite granodiorite, and lesser hornblende-biotite quartz monzodiorite and biotite quartz monzonite. According to Ray (1933), auriferous quartz veins are in a block about 1,200 ft wide between two major northeastward-dipping transverse faults. Quartz veins are generally 2 to 4 ft wide; they strike about N 80 E, and dip about 40 N . The veins appear to belong to a single system that is displaced by major cross faults. In places the vein system branches in the hanging wall; the footwall is marked by slickensides separating lode from fresh, unaltered country rock . The vein system is cut off to the east by a fault which is estimated to have offset the veins by 600 to 700 feet where they reappear in the workings of the adjacent War Baby mine (AN003). The veins contain two generations of quartz, the earlier generation is crumpled and recemented by the later generation. Some quartz is deposited in fissures and some in open spaces; thick quartz lenses that appear sporadically are probably caused by repeated movement along fissures. The gold mineralization occurs in well-defined ore shoots associated with pyrite, arsenopyrite, chalcopyrite, sphalerite, tetrahedrite, galena, and tellurides (Ray, 1933). Wallrock alteration seldom extends more than 10 to 12 inches beyond the veins. quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and chloritization occurs in the outer parts of the alteration zone (Ray, 1954). In 2005, Full Metal Minerals (2008, Lucky Shot; 2008, Drilling) discovered a high grade extension of the Lucky Shot shear zone and by the end of 2007, they had drilled 146 holes averaging 350 to 450 meters in length. Most were in the Coleman Block but they also discovered a northern extension of the mineralization called the Murphy Block. (Full Metal, 2008, Lucky Shot). Some notable intercepts in the 2007 drilling were 54.6 grams of gold per ton across 0.98 meters in the Murphy block, 17.3 grams of gold per ton across 1.0 meters in the Coleman block, 71.6 grams of gold per ton across 0.5 meters in the Coleman block, 21.3 grams of gold per ton across 0.5 meters in the Coleman block, and 77.2 grams of gold per ton across 0.2 meters in the Lucky Shot zone. From the 2007 drilling, Full Metal has defined a a mineralized area over 2,400 meters along strike and 700 meters down dip. In early 2008, planning was underway to determine whether to proceed with more drilling, drilling and underground work, or development. Full Metal indicates that the total production from the Lucky Shot and War Baby mines may have been over 620,000 ounces of gold at an average grade of 1.0 ounce per ton but those figures have not been verified.
Workings: Staked in 1918 or earlier. Taken under option by Willow Creek Mines in 1918. Development commenced in 1918 with open pits and a short tunnel. Considered to be one of the major gold producers of the district from 1923 to 1942, except for 1923 and 1928 when fires damaged the surface plant. Development included several open cuts and probably about a mile of underground drifting plus numerous stopes that averaged about 4 to 6 feet wide. Surface improvements consisted of a mill and power plant, assay shop, bunk houses to hold 100 men, and machine and blacksmith shops. The mill capacity in 1931 was 35 tons per day. The old tailings were cyanided starting around 1936 (Smith, 1938). Only the main crosscuts were accessible in 1950. In 2005, Full Metal Minerals (2008, Lucky Shot; 2008, Drilling) discovered a high grade extension of the Lucky Shot shear zone and by the end of 2007, they had drilled 146 holes averaging 350 to 450 meters in length, on the property, In early 2008, planning work was underway to determine whether to proceed with more drilling, drilling and underground work, or development.
Age: Late Cretaceous or younger; veins cut the Late Cretaceous Willow Creek Pluton.
Alteration: Chalcopyrite, sphalerite, tetrahedrite, galena, and tellurides (Ray, 1933). Wallrock alteration seldom extends more than 10 to 12 inches beyond the veins. quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and chloritization occurs in the outer parts of the alteration zone (Ray, 1954).
Production: Production records were combined for the Lucky Shot and the adjacent War Baby mine (AN003). Both mines were simultaneously operated by Willow Creek Mines. Stoll (1997) estimated the total amount of gold recovered from the Lucky Shot - War Baby vein on the northwest wall of Craigie Creek valley to be 252,000 ounces. Full Metal Minerals (2008, Lucky Shot) indicates that the total production from the Lucky Shot and War Baby mines may be over 620,000 ounces of gold at an average grade of 1.0 ounce but those figures have not been verified.
Commodities (Major) - Au, Cu; (Minor) - Pb, Te, Zn
Development Status: Yes; medium
Deposit Model: Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
8 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
66 - 100.5 Ma
|Intermediate granitic rocks|
Age: Late Cretaceous (66 - 100.5 Ma)
Description: Pervasively altered, zoned pluton; based on its distinctive aeromagnetic signature it is interpreted to extend at least to northern boundary of map area. Pluton has a 30- to 200-m wide outer margin of hornblende quartz diorite and lesser hornblende tonalite. Core is hornblende-biotite granodiorite, and lesser hornblende-biotite quartz monzonite and biotite quartz monzonite. Foliation is common, particularly along margins. Pluton hosts mineralized veins.
Reference: Wilson, F.H., Hults, C.P., Mull, C.G, and Karl, S.M. (compilers). Geologic map of Alaska. doi: 10.3133/sim3340. U.S. Geological Survey Scientific Investigations Map 3340, pamphlet 196. 
66 - 145 Ma
|Igneous: intrusive; Intrusive: granitic|
Age: Cretaceous (66 - 145 Ma)
Description: Okhotsk, Bering Sea, Pacific Alaska, Alaska Range
Comments: Orogen, magmatic arc/suite; Wilson & Hults, unpublished compilation, 2007-08
Reference: J.C. Harrison, M.R. St-Onge, O.V. Petrov, S.I. Strelnikov, B.G. Lopatin, F.H. Wilson, S. Tella, D. Paul, T. Lynds, S.P. Shokalsky, C.K. Hults, S. Bergman, H.F. Jepsen, and A. Solli. Geological map of the Arctic. doi:10.4095/287868. Geological Survey of Canada Map 2159A.