International Minerals Corporation (Toronto stock exchange: IMZ)(Swiss stock exchange: IMZ) has reported additional results from its ongoing reverse circulation drilling program at the Goldfield Main deposit at its 100%-held Goldfield gold project in southern Nevada.
The Goldfield project was acquired as part of IMZ's takeover of Metallic Ventures Gold Inc. ("Metallic"), which was finalized in February 2010.
Highlights from this drilling program (representing estimated true widths in meters ("m") and uncut gold grades in grams per tonne ("g/t")), include the following intercepts:
- 35.1m at 3.2 g/t in 2010-017, including 13.7m at 6.3 g/t
- 19.8m at 1.3 g/t in 2010-018
- 15.2m at 2.3 g/t in 2010-021
- 35.1m at 2.0 g/t in 2010-022
- 22.9m at 1.2 g/t in 2010-024
- 32.0m at 2.5 g/t in 2010-027, including 7.6m at 6.7 g/t
- 18.3m at 9.4 g/t in 2010-032, including 6.1m at 27.2 g/t
- 24.4m at 1.8 g/t in 2010-032
- 21.3m at 2.2 g/t in 2010-074
- 21.3m at 2.0 g/t in 2010-081
Note: Some of the above highlighted drill holes include zones of low-to-average grade material from the backfill in historical mine workings, but are predominantly in-situ mineralization.
Significant widths and gold grades were encountered in drilling through the backfilled areas of the historical mine workings suggesting that good-grade material was used to backfill those mined-out areas. IMZ is constructing a detailed computer model of these backfilled workings in order to quantify their volume and grade as they may have a significant positive impact on the economics of a potential mining operation at the Goldfield Main deposit.
Highlights of the results from drill intersections in backfilled areas are shown below:
- 25.9m at 1.0 g/t in 2010-029
- 6.1m at 12.3 g/t in 2010-029
- 30.5m at 1.8 g/t in 2010-030
- 21.3m at 1.6 g/t in 2010-036
- 15.2m at 3.3 g/t in 2010-044
- 19.8m at 1.3 g/t in 2010-052
Assay results for all 27 RC drill holes totaling 5,268m are summarized in Appendix 1 and shown on the plan map in Appendix 2. IMZ has now reported drill results for a total of 58 RC drill holes totaling 12,035m. See IMZ's news release of August 25, 2010 for the previous 31 drill holes at the Goldfield Main deposit.
Goldfield Main Deposit
The Goldfield Main deposit is one of three principal mineralized areas that have been evaluated on the property over the past two decades. The other deposits are Gemfield and McMahon Ridge (See Appendix 2)
Gold mineralization at the Goldfield Main deposit occurs primarily as narrow, high-grade veins, within tabular, gently-dipping, lower-grade mineralized zones. The majority of gold produced historically from the Goldfield district was mined from these high-grade veins but more recent open-pit production was sourced from the near-surface lower grade mineralized zones. Reported production from the district from 1903 to1960 is estimated to be 4.2 million ounces of gold at an average grade of approximately 18 g/t.
16 of the 27 drill-holes for which results have been received to date have extended the known mineralization at Goldfield Main and are expected to increase the existing NI 43-101 compliant resource base of approximately 242,000 Measured and Indicated gold ounces and 80,000 Inferred gold ounces (see tonnage and grade details below).
The other 11 drill-holes are located within the existing resource at Goldfield Main. Mined-out areas (generally 2-5m wide) encountered in the drilling program (designated as "Voids" in Appendix 1) are intercepts of old mine workings.
These new results continue to confirm that the mineralized bodies at the Goldfield Main deposit extend down-dip to the east, with many of the assay results indicating gold grades significantly higher than the average grade of the current mineral resource estimate (see below). The historical underground workings extend up to an additional 700m east of the eastern extent of the current IMZ drilling program (see Appendix 2), indicating the potential for a significant increase in mineral resources at the Goldfield Main deposit.
Goldfield Project - Overall 2010 Drill Program
This initial RC drilling program (approximately 20,000m in 93 drill holes) is designed to both increase the confidence level of the mineral resource base at the Goldfield Main deposit as well as expand the existing resource base. The drill program is part of a feasibility study with a targeted completion date in late 2011. In addition, IMZ expects to announce an updated mineral resource estimate for the Goldfield Main deposit before the end of the first calendar quarter of 2011.
A core rig will start drilling soon in order to (a) obtain samples for metallurgical testwork; (b) "twin" (duplicate) several RC holes in order to compare assay results and geological interpretation; and (c) to verify that IMZ's identification in certain drill holes of backfilled material from old mine workings is correct as it is often difficult to distinguish between friable, or highly broken, in-situ rock and backfilled material.
In other parts of the Goldfield District (outside of the three principal deposits) three additional drill targets have been developed. Approximately 5,000m of RC drilling is planned for these areas in the coming months.
Goldfield Project - NI 43-101 Mineral Resources
The previous NI 43-101 compliant independent mineral resource estimates for the Goldfield Main deposit are 242,000 ounces of Indicated resources, contained in 6.0 million tonnes ("Mt") at a grade of 1.2 g/t gold and 80,000 ounces of Inferred resources, contained in 1.9 Mt at a grade of 1.3 g/t gold.
Combined with the Gemfield and McMahon Ridge deposits, the current total resource estimate for the overall Goldfield project comprises 1,068,000 ounces of Measured and Indicated resources, contained in 28.8 Mt at a grade of 1.2 g/t gold and 105,000 ounces of Inferred resources, contained in 3.0 Mt at a grade of 1.1 g/t gold. The cut-off grade used was 0.34 g/t gold.
Mineral resource estimates at the Goldfield project have been conducted separately for the Goldfield Main deposit and the Gemfield/McMahon Ridge deposits: at Goldfield Main the mineral resources were estimated in 2002 by Mine Development Associates, with Scott Hardy, P. Eng, Neil Prenn, P. Eng and Steve Ristorcelli, R.P.Geo as the Qualified Persons ("QP's"); at Gemfield and McMahon Ridge the mineral resources were estimated in 2005 by Watts, Griffis and McOuat, with John R. Sullivan, P.Geo as the QP.
Sample preparation and analytical work for the Goldfield drilling program were carried out by Inspectorate Labs in Sparks, Nevada, an ISO 9001:2008 certified laboratory which employs industry-standard analytical methods. As part of IMZ´s QA/QC protocol, standard samples and blanks were inserted into the sample processing stream at a rate of one per 10 samples. Duplicate and alternate laboratory check samples also form part of this sampling protocol. The technical disclosure including drill results in this news release has been reviewed by IMZ's Qualified Person, Exploration Manager, Mark Cannuli.
Source: International Minerals Corporation