Hi Patrick,
Some information on the Alleghany Mining District.
gemandmineral.com
Potential of Original Sixteen to One Gold Mine
Geologic research in the fields of thermodynamics, geochemistry and plate tectonics during the past 20 years has greatly improved our understanding of crustal evolution and the distribution of metals in the earth's crust. Throughout the world in Canada, Africa and Australia, major gold deposits are found within a suite of rocks referred to as greenstones. The name greenstone refers to the color of the rock acquired during metamorphism: greenschist facies metamorphism. The Mother Lode and Alleghany mining districts also lie within a greenstone belt that contains world-class gold deposits, one of which is the Sixteen to One vein system with production of more than 31 metric tons of gold.
Our understanding of how this deposit formed has been evolving for over 85 years. A process called carbonate metasomatism formed ribbon quartz veins along en echelon faults that are secondary to the crustal suture known as the Melones fault. These secondary veins (the Sixteen to One), formed by replacement as aqueous fluids ascending through cracks in the earth's crust, removed accessory cations from wall rock minerals.
The Melones fault is the remnant of a compressive or transpressional environment common to convergent plate margins. This fault marks the boundary along which oceanic crustal rock is emplaced against the continent. The fracture system along which the quartz veins formed is an expression of the forces and motion along the crustal suture. The Alleghany fracture system originates at the Melones fault which is the conduit for the large volume of fluid that formed the vein system. The volume of fluid can be calculated with reasonable accuracy because the fluid composition is known from fluid inclusion chemistry. The volume of the end product, which is quartz, is known from mining. Fluid chemistry assures us that there is vein continuity to the depth of the Melones fault.
To evaluate the model extending the Sixteen to One ore chute at its recorded rake to the junction with the Melones fault, we compare pressure/temperature boundary conditions to a model developed during 20 years of thermodynamic research. The model states that gold precipitation occurs at 300-500 degrees C. and 1-3 kb. Fluid inclusion studies conducted on vein quartz from the Alleghany district indicate formation temperatures that lie within the above boundaries. Sensitivity of the system to the temperature gradient along the fluid path is simpler and more predictable than its sensitivity to the pressure gradient which is responsive to block motion in addition to depth. Considering Ferguson and Gannett's estimate of a two mile thickness of pre-Cretaceous overburden, the 2600 foot level is at 1 kb (PL). Sinking another 3,200 feet vertically to the Melones fault would only add another 0.25 kb to the boundary conditions. Another 23,000 feet of overburden could be added before reaching the 3 kb limit.
Projecting the rake of the Sixteen to One pay chute to the Melones fault indicates a distance as great as 12,600 feet. Presently the Sixteen to One gold deposit has been mined to a depth of 3,000 feet with production of more than a million ounces of gold. At a production rate of one million ounces per 3,000 feet, the potential exists for the production of several million ounces before the system dives steeply into the Melones fault.
A Chronological History of the Mine 1849 Beginning of the California Gold Rush 1852 Placer Mining began in the Alleghany District with the discovery of the first gold by Hawaiian sailors. 1853 Earliest report of lode mining (Rainbow and Irelan mines). 1861 Peak of placer production in the Alleghany district. 1870 The Placer Act limits placer claims to 160 acres. 1882 A 1000 troy ounce slab of quartz and gold from the Rainbow mine on display in San Francisco. 1891 Ruby and Bald Mountain Extension mines only ones to maintain payroll. 1891 Three-way partnership formed to relocate vein (Tightner vein) from the Knickerbocker tunnel. 1896 William Jennings Bryan gave "Cross of Gold" speech advocating coinage minted from 16 parts silver to 1 part gold. (16-1) 1896 Tom Bradbury located the Sixteen to One vein in his backyard. March 14, 1900 U.S. on gold standard. 1908 H.L. Johnson applies for patent on Contract, Contract Extension and consolidates Rainbow, Red Star & El Dorado. 1908 T. Bradbury options Sixteen to One to partnership of Lawson, Wilson and Van der Beugle, they hit rich ore and Wilson slips out of town with the gold. 1911 H.L. Johnson sells his interest in the Tightner to O'Brien, Foote & Assoc. ($550,000). October 6, 1911 J.G. Jury, W.I. Smart and H.K. Montgomery incorporate as Original Sixteen to One Mine, Inc. 1918 Tightner Mine has produced $3M and distributed $.5M in dividends under Foote & O'Brien. 1919 Sixteen to One's Twenty-one Mine litigation. Settlement of $93,000 in favor of Sixteen to One which bought the Twenty-one Mine for $60,000. 1922 Sixteen to One has discovered orebodies to the value of: $2M, $1M, and several at $.2M. April 23, 1923 Dr. R.G. Raymond (Mariposa Mine Assoc.) quit-claims Ophir and Eclipse properties to the Sixteen to One. 1924 80 pound lot of ore from the Sixteen to One yields $5,000. 1924 The "Sixteen" has paid $1.283M in dividends. 1925 Sixteen to One acquires Tightner Mine from Alleghany Mining Co. (Fred Searles). 1928 a 160 pound chunk of ore form the Sixteen to One mine yields $28,000. 1930 Depression. Payroll averages 80 to 100 men. 1934 Price of gold fixed at $35 per troy ounce. 1934 Bullion receipts of the Sixteen to One total $.578M for the year. Dividends that year were $.287M (almost 50% of bullion receipts). 1940 Up to this year, $4.4M in dividends paid out. 1940 Peak of U.S. gold production. 150 tons for 1940. August 25, 1941 F.F. Cassidy buys the South Fork properties on behalf of the Sixteen to One. October 8, 1942 War Production Board Order L-208 reduces mining activities in many mines to nil. 1942 Up to this date Sixteen to One has mined .608M tons of ore with a yield of .749M ounces of gold. Handsorting totalled 164 tons with 73.25% of the yield. April 15, 1943 Sixteen to One acquires Rainbow property. 1954 Fire in hoist room of the Tightner shaft. October 18, 1954 Rainbow Extension and Fraction acquired. December 9, 1965 Sixteen to One mine phases out of mining, having produced over 1M ounces of gold. March 17, 1968 London Pool dissolved; U.S. off the gold standard. January 1, 1975 U.S. citizens permitted to own gold. 1976 Lease to the Sixteen to One Mining Co., an unrelated Nevada Corporation. 1977 Tightner Mines merger. Proxy fight for the control of the company commences. January 21, 1980 Price of gold reaches a high of $850 per ounce. July 14, 1983 Lucky Chance Mining Corporation acquires Sixteen to One Mining Co. and changes name to LCM Corporation. April 27, 1984 High-grade ore discovered by LCM Corporation. November 14, 1984 Bald Mountain Partnership options Forest properties to Sixteen to One. January 27, 1985 Company modifies lease. Red Star claim reconveyed to Sixteen to One. March, 1985 Company acquires old school in Alleghany. April 1, 1985 Transwestern Mining takes over as operator of central lease from Kanaka Creek Joint Venture. (KCJV). May 13, 1985 Completion of first audit in thirty years. February 24, 1985 Lowest price of gold in this decade. $284 per ounce. January 26, 1986 Mine office destroyed by arsonist. June 19, 1987 Royal Gold, Inc. replaces Transwestern Mining as operator of KCJV. July, 1987 Acquisition of lease of Osceola Mine. September 11, 1987 Successful completion of Private Placement Financing. $430,634. April 1988 KCJV gold production approaches minimum royalty level. May 19, 1989 Public listing on the Pacific Stock Exchange. June, 1989 Completion of initial phase of Red Star rehabilitation. June 3, 1991 Agreement with Royal Gold terminated. Company reconsolidates its claims. Jan 26, 1992 Hand held metal detectors work magic. ~1000 ounces of gold discovered. August, 1993 The Whopper discovered. An eighteen pound specimen, mined from the 2200 level, contains 141 ounces of gold. December 17, 1993 Greatest recorded single day production. 2500 ounces were mined from the 1330 stope. (value:$1M). January, 1994 Company purchased Brown Bear Mine in the Trinity Alps. October, 1994 First breaking of rock on the 2483 winze. This represents the first deepening of the mine in forty years. March, 1995 Sixteen to One equips its own mine rescue team. July, 1995 5000 ounces mined in ten days. (value:$2M). August, 1995 Original Sixteen to One Mine announces first dividend in 40 years.
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