Overview
Florida Canyon is an open pit and heap leach gold recovery mining operation that has been operating continuously with sporadic periods of interrupted production since 1986. Florida Canyon is located approximately 45 miles southwest of Winnemucca, Nevada, adjacent to Interstate Highway 80. An updated mineral resource was prepared by SRK Consultants (US) “The Independent Technical Report, Mineral Resource Update for the Florida Canyon Mine, Pershing County Nevada, report date, November 29, 2018” (SRK, 2018a). FCMI is a 100% owned subsidiary of Argonaut Gold. Argonaut acquired FCMI through its acquisition of Alio Gold Inc in July 2020.
Geology
The Florida Canyon Gold Mine area is situated in northwestern Nevada within the Basin and Range physiographic province, which is typified by a series of northward-trending elongate mountain ranges separated by alluvial valleys. The Florida Canyon area is dominated by a major regional structural zone, termed the Humboldt Structural Zone, which is interpreted to be a 200-km wide north-easterly-trending structural zone with left-lateral strike slip movement. One of the principal structural features within the Humboldt Structural Zone is the Midas Trench lineament, which abruptly terminates the north end of the Humboldt Range. Mineralization and alteration in the Florida Canyon Gold Mine is localized where the Midas Trench lineament is intersected by the north-south trending Basin and Range frontal faults on the northwest side of the Humboldt range.
Florida Canyon is a large, relatively young epithermal gold deposit adjacent to an active geothermal system. The close spatial association with the geothermal system has led to a general belief that Florida Canyon is a hot spring-style, epithermal gold deposit. Hydrothermal alteration assemblages and the mineralogy of both oxidized and unoxidized gold mineralization at Florida Canyon have been interpreted as having formed in a low-sulfidation, epithermal environment.
The deposit type is a large fault/fracture-controlled gold system, the overall extent being defined by alteration and oxidation of host meta-sedimentary rocks. Mineralization is preferentially located along major structural trends, in associated adjacent fracturing and rock foliations, and as disseminations in favorable host lithologies. The overall extent of mineralization, in surface exposures in the pit areas, is approximately 7500 ft east-west by 6200 ft north-south and can be up to 800 ft in vertical thickness.
History
Florida Canyon’s production history dates to 1986. Following a rehabilitation period, the mine re-started production in April 2017 and achieved commercial production in December 2017. In July 2018, SRK Consulting (US) Inc. was retained by FCMI to prepare a life of mine (LOM) plan at a prefeasibility study (PFS) level for the Florida Canyon Gold Mine. In the preparation of this technical report, SRK reviewed and used information in the amended preliminary economic assessment (PEA) report dated January 27, 2017 and prepared by Mine Development Associates (MDA, 2017).