Crown one of few juniors actively exploring at Carlin

The Cord Ranch property owned by Crown Resources (VSE) is one of the few sites of exploration activity by a junior company within the Carlin Trend. The property is about 20 miles south-southeast of Carlin, Nev., as the crow flies, and somewhat further by paved highway and dirt track.

Cord Ranch, recently visited by The Northern Miner, covers about 34,000 acres in the southern portion of the main Carlin gold trend. The huge gold operations of Newmont Mining and American Barrick Resources lie about 30 miles to the northwest, while Kennecott Corp. and Nerco Inc.’s Alligator Ridge mine and Placer Dome’s Bald Mountain mine lie about 45 miles to the southeast. Newmont’s Rain gold mine is 10 miles to the north. Crown currently has one reverse circulation rig operating on the property and has spent in the order of US$750,000 so far this year. Expenditures are expected to reach US$900,000, about 30% more than planned, before winter forces the company to shut down the program.

The company is concentrating on delineating reserves in the Main and Central zones on the Pinon Range area of the property.

The two zones are situated under a north-south trending ridge which sits in an area of rolling range land dotted with cattle and crossed by the occasional barbed-wire fence.

The two zones lie along the fold axis of an antiform trending in the same direction as the ridge while plunging at 25-30 degrees to the south. The Main zone is the most prospective since it lies near surface while the Central zone, about 1,500 ft. to the north, is deeper at about 200 ft. below surface.

The Main zone measures about 300 ft. wide in the direction of the fold axis and extends over 2,500 ft. across the axis and along the eastern limb. The thickness of the zone ranges from 20 ft. up to 150 ft.

The preliminary reserve estimate for the Pinon Range area is 3.25 million tons grading 0.037 oz. gold per ton. About 70% of this reserve is in the Main zone which Victor Calloway, project geologist, estimated would have a stripping ratio in the order of 1-to-1. He estimated that the strip ratio in the deeper Central zone would probably be closer to 3-to-1.

Calloway noted that preliminary metallurgical work on the Pinon gold mineralization indicates the deposit will not be heap leachable and will require milling to recover the gold.

The current drilling program is designed to expand the size of the deposit, particularly the Central zone which remains open, as well as to bring reserves into the proven category.

Calloway estimated a threshold tonnage of more than 10 million tons would be required to make a milling operation viable.

Outcrops tend to be limited to ridge areas since the adjoining valleys and much of the hill sides are covered with alluvium washed down through thousands of years of weathering. Because of the cover, Calloway said the best exploration tool on the property appears to be soil geochemistry, with an emphasis on arsenic and antimony as well as gold since the three tend to be associated.

Crown completed a detailed soil sampling program extending over 10,000 ft. to the north of the Main and Central zones over a 5,000-ft.-wide area. The program identified an 8,000-ft.-long anomaly trending in the same direction as the Main and Central zones. Crown plans to drill-test the anomaly later this year.

In addition to the drilling, the soil grid will be extended to the east. About 1.5 miles to the east of the Pinon, the company has drilled more than 20 holes on the Dark Star area, identifying a 3,000-ft.-long mineralized zone. Half the holes intersected near-surface mineralization grading greater than 0.015 oz. gold in an area measuring roughly 800×400 ft. Preliminary estimates place reserves at about 4.5 million tons grading 0.022 oz. gold. Calloway notes that the mineralization “leaches like a bandit” with initial bottle roll tests returning recoveries in excess of 80%.

Christopher Herald, president of Crown, said this testing gives the Dark Star area real potential to become a heap leach operation with capital costs significantly lower than that required for a milling operation in the Pinon. In describing area geology, Calloway said the Pinon Range gold is primarily associated with the contact between the Webb formation of shale and sandstone, and the Devils Gate limestone below. He notes that the entire Webb formation appears to have been weakly mineralized on a regional scale prior to localized mineralizing events concentrating higher grades. He adds that the axis of the antiform is the prime exploration target in the Pinon area. Victor says the geological setting of the Dark Star area is more difficult to determine but is believed to be associated with the Chainman Shale formation above the Webb formation.

Crown plans to do further drilling on the Dark Star area next year.