Comet Resources has wasted no time at its Santa Teresa gold project in Mexico, unveiling a high-grade maiden resource for the project, tipping the scales at 369,000 tonnes at an impressive 7.47 g/t gold. This initial estimate perhaps understates the potential of the deposit which hosts a wealth of high-grade intercepts and has only been drilled to 300m depth.

An evaluation of the resource estimate shows that it utilises a lower cut-off of 2.5 g/t gold, based on the economic parameters for the mining of quartz vein hosted deposits in central America. However, it is particularly sensitive to a ‘top cut’, or the removal of the ultra-high-grade results that may skew the overall resource estimate.

If a top cut of 50 g/t gold is applied to the Santa Teresa, the inferred resource climbs to 414,000 tonnes at a very healthy 8.94 g/t gold, though if the top cut is completely removed, the overall tonnage remains the same, but the grade skyrockets to 13.07 g/t gold.

The dramatic upgrade of the potential estimate is a strong indication of just how much high-grade, free-milling gold is present in the deposit and might be easily extracted through a simple processing circuit.

The initial JORC compliant Resource is the first step for Comet in moving forward with Santa Teresa. Through this process we have increased our understanding of the mineralisation. It is also interesting to see the sensitivity of the resource to different top cap grades. With the Resource being open at depth and along strike, I am confident that we can extend mineralisation with the upcoming drilling.Comet Resources Managing Director, Matthew O’Kane

Comet’s Santa Teresa gold project is located in the gold-rich El Alamo district of Baja California in Mexico, just south of the US-Mexico border and around 250km southeast of San Diego in California. The project is composed of two mineral claims covering over 200 hectares and taking in the high-grade Santa Teresa gold deposit and its surrounds.

Regional gold production in the EL Alamo district dates back to the late 19th century before being curtailed by the Mexican Revolution in 1912. Historical gold production in the region is estimated to be in the order of 100,000 and 200,000 ounces of gold from alluvial workings, the artisanal underground mine at Santa Teresa and its surrounds.

Modern exploration at Santa Teresa has delivered a swag of high-grade intercepts in diamond drilling, including 2m at 32.4 g/t from 19m, 3.9m at 39.0 g/t from 121m and 1m at 958.4 g/t gold from 239m. The previous owners of the deposit estimated Santa Teresa to host a resource of around 64,000 ounces, yet Comet’s revised estimate blows this out of the water and is nearly double the previous number.

The new JORC resource is based upon the results from 32 diamond drill holes emplaced by Premier Gold Mines in 2008. The holes were drilled perpendicular to the interpreted strike of the quartz vein array that hosts the gold mineralisation, with excellent sample recovery across the drilling program.

Preliminary metallurgical test work on the Santa Teresa ores by ALS Global in Canada, shows that a simple gravity circuit recovers 22 to 77 per cent of the contained gold, with cyanide leach test work ongoing. Comet says that they expect total recoveries of gold to be approaching an astonishing 100 per cent.

Comet’s first-pass evaluation of the resource modelling indicates that the deposit is seemingly amenable to small-scale underground mining with minimal dilution due to excellent ground conditions. The evaluation also shows that the deposit remains unconstrained by drilling and is open along strike and at depth, delivering plenty of upside for future exploration.

Comet’s evaluation of Santa Teresa is ongoing but with a high-grade gold resource now loaded into its back pocket, it won’t be long until the drill is back on site and making dust as the aspiring, and well-funded gold developer seeks to build on its resources and make the jump into production.

Original Article: https://thewest.com.au/business/public-companies/comet-unveils-high-grade-mexican-gold-resource-c-1384002