Both fissure veins and the bulk-mineable type of mineralization are present at Florida Mountain and both have contributed to past gold and silver production. The veins cropped out intermittently near the crest and on the flanks of Florida Mountain, in some cases with lateral continuity of 1.6 kilometers (1 mile) or more, even though vein widths were usually only a few meters or less. Dips are reported to be 75° to 80° W, transitioning in their northern extents to steep east dips (Piper and Laney, 1926).
Mosser (1992) summarized the vein mineralization as follows:
“…Mineralization is strongly controlled by NNW-trending faults, and to a lesser degree by arcuate and ENE structures. Host rocks display a definite influence on mineral distribution. Within the granodiorite and basalt, where most of the historic production occurred, the veins are narrow and tight. However, within the more reactive and permeable quartz-latite and rhyolite units, the mineralization is more disseminated so that significant bulk mineable potential exists… The vein deposits are dominated by quartz and adularia gangue. Quartz occurs in a variety of forms in a definite paragenetic sequence…. Hypogene gold and silver mineralization varies little with depth across known levels and is dominated by electrum, acanthite, and the silver sulfo-selenide aguilarite….”
In the quartz latite and rhyolite, at least some of the veins branch upward into multiple narrow veins and vein-cemented breccia, separated by intensely altered rhyolite, to form sheeted vein and breccia zones as much as 6.1 meters (20 feet) or more in width. These broader sheeted vein and breccia zones comprise the bulk-mineable style of mineralization at Florida Mountain, particularly where adjacent fracture networks and flow bands in the rhyolite have been permeated with narrow, discontinuous quartz and breccia veinlets. Four such zones were described by Mosser (1992), referred to as the Tip Top, Stone Cabin, Main Trend (Black Jack), and Clark deposits. The mineralogy and paragenesis of the gold and silver mineralization are similar, if not the same, as that described for the fissure veins. Details of the mineralogy and a fluid inclusion study were presented by Mosser (1992).1
1. NI 43-101 Technical Report for the DeLamar and Florida Mountain Gold-Silver Project, Owyhee County, Idaho, USA. Dated October 31, 2023.
The Florida Mountain Project is located 8.5 kilometers away from the Company’s DeLamar Project in southern Idaho. The two projects are connected by an all-weather haul road that was used historically by Kinross to transport mineralized material from Florida Mountain to DeLamar. Historical underground mining at Florida Mountain from the 1830s to 1910s produced a total of 133,000 ounces gold and 15.4 million ounces of silver. Modern open pit mining was conducted by Kinross Gold in the 1990s and produced an additional 124,500 ounces of gold and 2.6 million ounces of silver.
The open pit was closed in 1998 due low metal prices and the Florida Mountain Project, as an extension of the DeLamar Project, was placed on care and maintenance. The site of the open pit mine has been fully reclaimed and no drilling has been conducted on the property since the mine’s closure.
The Florida Mountain project hosts a significant drill database consisting of over 1,050 drill holes. The majority of this historic drilling was completed by Kinross Gold and NERCO Minerals to define an deposit amenable to open pit mining.
Integra acquired the Florida Mountain Project in January 2018. The Florida Mountain property is primarily free of all royaltes and other types of financial encumbrances1.
1. NI 43-101 Technical Report for the DeLamar and Florida Mountain Gold-Silver Project, Owyhee County, Idaho, USA. Dated October 31, 2023.
