American Bonanza Gold Mining Corp - Bonanza
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 General        Location        Geology        Past Work Program        Current Work Program

  • Property covers +2 sq. miles (+500 HA) - 100% owned, subject to capped royalty

  • Former open pit production: 527,000 oz Au, average grade 0.08 opt (2.7 g/t) Au

  • Historical Resources currently in place at Gold Bar: 3.6 million tons grading 0.100 opt (3.4 g/t) containing 360,000 ounces of gold in the Gold Bar Main Pit vicinity, and 2.5 million tons grading 0.056 opt (1.9 g/t) containing 140,000 ounces of gold in the Gold Canyon area.  

  • Historical Resources contain 500,000 total ounces of gold in the Gold Bar Main and Gold Canyon areas

  • Structural intersection of Battle Mountain - Eureka Mineral Belt and Cortez Rift

  • Targets and deposits are mainly in Lower Plate carbonate Windows through the Roberts Mountain Thrust Fault

  • The district displays average grades and feeder structure grades that are elevated relative to other sediment hosted gold districts - ideal location for the search for high grade, sediment hosted deposits (Meikle, Deep Star, Rain type deposits)

  • Exploration indicates a +100,000 oz Au deep deposit with best intercepts of 12m grading 0.17 opt (5.8 g/t) Au, 18m grading 0.13 opt (4.5 g/t) Au.

  • High grade feeder faults have not been specifically explored to depth or along strike - over 2 miles of prospective structure have been identified to date

  • Bonanza acquired the property in late 1999, focus thus far has been data cleaning and processing, and 3-D (Vulcan) modeling to refine drill targets

  • Min. of two (2) high grade underground sediment hosted targets are drill ready

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The Gold Bar project in Nevada comprise 70 patented and unpatented claims covering 5 square kilometres which are prospective for gold.  Gold Bar is subject to a 2 percent net smelter royalty capped at US$1,000,000 on future production.

The Gold Bar properties are located in the Battle Mountain/Eureka mineral trend in east-central Nevada and cover a past-producing bulk tonnage gold mine with 485,000 oz of historic production. Historic reserves (now characterized as subeconomic resources) in place at Gold Bar have most recently been quoted at 6.1 million tons grading 0.082 opt by Atlas Corporation and its subsidiaries (collectively “Atlas”).  Several drill targets are ready to test, including the 150,000 ounce Millsite-Gold Bar Pit area (estimated by Granges).  Numerous other economically interesting areas exist on this historic producer.

G.F. McArthur, P.Geo. (“McArthur”), an independent consulting geologist of Vancouver, British Columbia prepared a report dated September 8, 2000 (the “McArthur Report”) on the properties which the Corporation acquired in the “Bonanza Acquisition” in late 2000, prepared in accordance with what was then the proposed National Instrument 43-101, Companion Policy 43-101 CP and Form 43-101 F(1) Standards of Disclosure for Mineral Projects, as described in British Columbia Securities Commission’s Notice and Interpretation Note 2000/12 dated March 22, 2000; the National Instrument came into force on February 1, 2001.

Following is a summary of the McArthur Report on the Gold Bar properties.

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The Gold Bar properties are located in Eureka County, 50 kilometres northwest of Eureka, Nevada. They are accessible by vehicle, travelling 33 kilometres west on US 50, then north, 25 kilometres on dirt roads.

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The Gold Bar properties lie in the Battle Mountain/Eureka structural mineral trend. They are underlain by a complexly folded and imbricately thrusted sequence of Paleozoic shelf carbonates and deeper water shales and cherts. The Paleozoic rocks are unconformably overlain by a thick sequence of undifferentiated Tertiary volcanics and sediments.  Recent pediment gravels fill the valleys.

Primary regional structures are northwest trending strike-slip and dextral wrench faults. These are associated with north-northwest trending dextral synthetic faults, north trending normal faults, northeast trending sinistral antithetic faults and east-west trending compressional faults. 

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Past Work Program

The Gold Bar property has no record of historic production prior to exploration by Atlas in 1983. Production began at the Gold Bar pit in 1987 and continued until the mine closed in 1994.  A total of 7,514,600 tons grading 0.074 opt gold were produced.  Recoveries averaged 87 percent, resulting in production of 485,000 ounces of gold.

During their work in 1983 to 1994, Atlas completed mapping, geochemistry, geophysics and drilling.  These programs resulted in the discovery or optioning of mineralization at Gold Bar, Gold Pick, Goldstone, Gold Canyon, Gold Ridge, Cabin Creek, Pot Canyon and Hunter.  Open pit mining was carried out at all but Pot Canyon and Hunter.  The Gold Bar and Gold Canyon areas currently comprise the Corporation’s Gold Bar Properties.

In late 1994, Atlas entered into an agreement with Homestake on the southern and northern claims areas. Homestake drilled 26 holes totalling approximately 7,282 metres (23,890 feet) and completed geological mapping, geochemistry and geophysics.

In 1995, Atlas signed an agreement with Granges who completed mapping, geochemistry, geophysics and the drilling of 33 holes totalling 7,314 metres (24,980 feet).

In 1997, Barrick optioned most of the Atlas claims. They completed a program of mapping, geochemistry and geophysics. Fifty holes were drilled in 1997 and a further 33 holes in 1998 totalling 10,796 metres (35,420 feet).

Historic in situ resources remaining at the Gold Bar property as calculated by Atlas are as follows:

  • 3.6 million tons (3.3 million tonnes) grading 0.100 ounce per ton (3.4 g/t) gold in the Gold Bar Deposit;
  • 2.5 million tons (2.3 million tonnes) grading 0.056 ounce per ton (1.9 g/t) gold in the Gold Canyon deposit.

Granges calculated a geological resource in 1996 for the newly discovered Millsite Deposit of 1.626 million tons (1.475 million tonnes) grading 0.091 opt (3.1 g/t) gold containing approximately 150,000 ounces of gold. These resources were calculated using 30.48 x 30.48 x 4.6 meters (100 x 100 x 15 foot) blocks with a 0.025 opt (0.86 g/t) gold cutoff and a 30.48 meter (100 foot) search radius.

These historic resource estimates are viewed by the Corporation as mineralized zones representing three-dimensional gold geochemical anomalies. These anomalies are used to focus the Corporation’s exploration efforts onto high-grade underground mineable targets, versus the previous emphasis of exploration which targeted low-grade bulk mineable mineralization.

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Current Work Program

The vast data acquired by Atlas and other companies has been compiled and converted into digital format to define areas of high-grade gold within the known or recently mined out gold deposits. These areas of interest are being further evaluated to define drill targets at depth below the existing open pits. Several such areas have been noted to date near the Gold Bar pit, the Millsite target and the Gold Canyon pit. 

The primary focus of current work at Gold Bar is deep exploration drilling below the largest of the open pits mined during modern times.  The target deposit is a deep, high grade Carlin-type gold deposit similar to the Meikle Mine on the Carlin trend.  These deposits, while deep, have significant positive economic impact. 

The Gold Bar Main Pit locale is a good site for this exploration because of the following geological characteristics.  The property is located at the intersection of the Battle Mountain–Eureka Mineral Belt and the Cortez Rift, two of the major gold mineral belts in Nevada.  Local geology is extremely favorable, with the Roberts Mountains Thrust Fault and erosional windows through the thrust faults present on the property.  The most favorable host rock formation for Carlin-type disseminated gold deposits is the Roberts Mountains Formation limestones, which are present at depth on the property.  Classic feeder-fault systems apparently exist below the gold deposits that were mined during modern times in open pits, and are guides to potential deeper, high grade Carlin-type gold deposits.

The results from the first deep hole completed at Gold Bar were announced during March 2004, and are very positive from an exploration point of view.  The Roberts Mountains Formation favorable host rocks were encountered at depth near the postulated feeder fault system below the Gold Bar Main open pit. 

The Roberts Mountains Formation in the core is hydrothermally altered and silicified.  Significant geochemical anomalies are present in the Roberts Mountains Formation in the core.  This information is very positive and suggests that the target high grade gold deposit may be nearby.  Additional work including geophysical surveys and further core drilling in the area is planned to follow these results up during 2004.

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