Florida Mountain Deposit Gold and Silver Resource Estimate
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- Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
- Oxidized and Transitional Mineral Resources are reported at a 0.2 g AuEq/t cut-off in consideration of potential open-pit mining and heap-leach processing. Unoxidized Mineral Resources are reported at a 0.3 g AuEq/t cut-off in consideration of potential open pit mining a milling / agitated leaching or flotation processing. The Mineral Resources are constrained by pit optimizations.
- Gold equivalent grades were calculated using the metal prices and recoveries presented elsewhere in this press release.
- Rounding as required by reporting guidelines may result in apparent discrepancies between tonnes, grades, and contained metal content.
- The Effective Date of the Mineral Resources is May 1, 2019.
- The estimate of mineral resources may be materially affected by geology, environment, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues
The terms “mineral resource”, “measured mineral resource”, “indicated mineral resource”, “inferred mineral resource” used herein are Canadian mining terms used in accordance with National Instrument 43-101 - Standards of Disclosure for Mineral Projects (“NI 43-101”) under the guidelines set out in the Canadian Institute of Mining and Metallurgy and Petroleum (the “CIM”) Standards on Mineral Resources and Mineral Reserves, adopted by the CIM Council, as may be amended from time to time (the “CIM Definition Standards”). Inferred mineral resources’ have a great amount of uncertainty as to their existence, and as to their economic and legal feasibility. It cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to a higher category. These definitions differ from the definitions in the United States Securities and Exchange Commission (the “SEC”) Industry Guide 7 (“Industry Guide 7”). United States investors are cautioned not to assume that all or any part of measured or indicated mineral resources will ever be converted into mineral reserves. United States investors are also cautioned not to assume that all or any part of an inferred mineral resource exists, or is economically or legally mineable.
Under Industry Guide 7, a mineral reserve is defined as a part of a mineral deposit which could be economically and legally extracted or produced at the time the mineral reserve determination is made. While the terms “mineral resource”, “measured mineral resource”, “indicated mineral resource”, and “inferred mineral resource” are recognized and required by Canadian regulations, they are not defined terms under Industry Guide 7 and historically they have not been permitted to be used in reports and registration statements filed with the SEC. As such, information contained herein concerning descriptions of mineralization and resources under Canadian standards may not be comparable to similar information made public under Industry Guide 7 by U.S. companies in SEC filings.
Florida Mountain Geology
The Florida Mountain Project is a low-sulphidation gold-silver epithermal system similar to that of the DeLamar Gold and Silver Project. The important exception between DeLamar and Florida Mountain is that the Late Cretaceous Silver City granite crops out on the flanks of Florida Mountain and was extensively penetrated by workings of historic underground mines. Field relations demonstrate the lower basalt flows partially buried an erosional, paleo-topographic high of Silver City granite. Surface exposures and maps of the underground workings, as well as early drilling at Florida Mountain, led Lindberg (1985) to infer the granite forms a northeast-trending ridge beneath a relatively thin capping of quartz latite, tuff breccia, and one or more flows of rhyolite. Similar to the DeLamar area, both fissure veins and the bulk-mineable type of mineralization are present at Florida Mountain and have contributed to past gold and silver production.1
Florida Mountain Metallurgy
The NERCO Mineral Company conducted extensive column-leach and agitation-leach tests on samples of mineralized drill core from the Sullivan, Stone Cabin, and Clarke areas of Florida Mountain in the 1980s (Statter, 1989). The results of the column-leach tests, which were run for approximately 60 days, are summarized in the table below.
NERCO Florida Mountain Column-Leach Tests (from Statter, 1989)1
Integra plans on conducting further metallurgical test work on Florida Mountain mineralization in the future.
As indicated in the table above, gold and silver recoveries in these tests ranged from 52% to 95% for gold, and 32% to 54% for silver on crush fractions ranging from 0.25 to 2 inches, indicating potential amenability of Florida Mountain mineralization to future low cost heap-leaching methods.
1. NI 43-101 Technical Report and Preliminary Economic Assessment for the DeLamar and Florida Mountain Gold – Silver Project, Owyhee County, Idaho, USA. The effective date of report is September 9, 2019.