| Basis for focus area |
Cluster of MRDS producers, past producers, prospects and occurrences for fluorite and gold associated with Fluorspar Canyon detachment fault. |
| Identified resources |
Identified gold resources; historical production of copper, fluorite, gold, lead, molybdenum, and silver. |
| Production |
117.648 short tons of fluorite was produced from the Daisy mine between 1919 and 1961 (Cornwall and Kleinhampl, 1964). Gold production from the Daisy mine between 1997-2001 was 104,251 oz. |
| Status |
Past mining; ongoing gold-silver exploration by Coeur Mining. |
| Estimated resources |
At the time of the 1994 discovery of the Daisy gold deposit, the Au resource was listed as 1,080,800 oz. Proven and Probable reserves at Daisy in 1998 were 4,162,000 tons of ore grading 0.0333 oz/t Au for a total of 138,000 oz Au. In 2006 Canyon Resources Inc. announced that based on recent drill results at the Reward Project (part of Daisy), resources aggregate 2,640,000 tons grading 0.032 oz/t Au Measured+Indicated. |
| Geologic maps |
Stewart and Carlson (1978), scale 1:500,000; Cornwall and Kleinhampl (1961), scale 1:62.500; Cornwall and Kleinhampl (1964), scale 1:48,000. |
| Geophysical data |
Adequate Rank 2 aeromagnetic and inadequate Rank 3 aeroradiometric coverage. |
| Favorable rocks and structures |
Steeply dipping faults and shear zones in carbonate rocks (Cornwall and Kleinhampl, 1961, 1964). |
| Deposits |
Daisy mine (MRDS dep_id: 10310491), Desert Antimony, Colosseum mine, Green's mine, Henry, Mohawk mine Annex, Mountain Pass Antimony, Pacific Fluorite mine, Pitcairn, Taylor mine. |
| Evidence from mineral occurrences |
MRDS. |
| Geochemical evidence |
Fluorite contains 70 to 150 ppm U (Cornwall and Kleinhampl, 1964; Smirnov and Dublyansky, 2001). Ore materials are free gold, fluorite, unknown uranium mineral, cinnabar, and clay. |
| Geophysical evidence |
Unknown. |
| Evidence from other sources |
Significant local structures are the Bullfrog Hills Caldera, Fluorspar Canyon detachment fault, northeast-trending, steep dipping, right lateral tear faults and gently northwest dipping thrust faults. The principal structural ore control for all three Au mineralized zones is normal faulting. The highest grade ore zones are associated with intersections of high-angle and low-angle faults. A low-angle fault forms the footwall of the Au mineralization in the favorable host rocks at the West Zone. In the South Zone, disseminated Au mineralization occurs in favorable host rocks in the footwall of a low-angle fault. |
| Comments |
This area is near the Yucca Mountain waste repository site. Minor production of Hg (from cinnabar) in region has also been documented, but it is currently not clear how Hg, Ag, Au, and fluorite mineralization are related. Some of the commodities previously mined in this district could be related to a different mineral system (for example, Marine chemocline). In 1945 the USBM drilled 12 diamond drill holes totaling 3,661 feet to define the limits of the fluorite deposit. Exploration of the Daisy mine area for Au began in the 1970s by Cordex Exploration Company after discovery of the Stirling (Sterling) mine farther to the south. Cordex discovered Au mineralization in the Nopah shale-limestone sequence in the vicinity of the old Daisy Fluorspar mine. Meanwhile, based on a report by Ahern and Corn (1981), U.S. Borax located claims in the Fluorspar Canyon area and drilled the volcanic-hosted mineralization at the Secret Pass Zone. Both of these independent exploration programs led to the delineation of mineable Au resources by 1994. Rayrock Mines Inc. began production in 1997 at the Daisy Gold mine and by its second year of operation produced and sold 32,504 oz Au. Glamis Gold, Ltd. acquired the Daisy mine via its merger with Rayrock in February 1999 and mined it that year until mining was completed in December 1999. Gold production continued over the next two years with concurrent rinsing and reclamation activity during which time an additional sulfide resource was delineated at the Daisy mine. The Reward Project was subsequently developed at the Daisy Property with Au production planned for late 1999. The Reward Project was anticipated to extend Daisy's mine life to 2002. In 2004, the Daisy mine was listed by Nevada Department of Environmental Protection as in active reclamation status, and in 2006 was still listed by the BLM as a closed mine in reclamation status. In January 2005, Canyon Resources Inc. acquired the Reward gold property near Beatty through mineral leases with several private owners. |
| Cover thickness and description |
Unknown. |
| Authors |
David A. Ponce, Joshua M. Rosera. |
| New data needs |
Geologic mapping, high resolution geophysics. |
| Geologic mapping and modeling needs |
1:24,000 scale geologic mapping. |
| Geophysical survey and modeling needs |
High resolution, Rank 1 aeromagnetic and aeroradiometric coverage needed. |
| Digital elevation data needs |
Lidar mostly inadequate; some areas meet 3DEP base-level specifications. |
