Trigon steps into Utah uranium

Vancouver — Diamond explorer Trigon Exploration Canada (TEL-V) is branching out into the uranium business, having acquired a land position in central Utah’s historic Marysvale mining district.

After evaluating past drill data, the company optioned the Marysville project, including the historic Phillips property, which underwent extensive drilling and a resource estimate.

In the late 1970s, Union Oil drilled two dozen holes in the project area. A few years later, Phillips Petroleum’s uranium subsidiary acquired the project and drilled a further 190 holes totalling almost 35,000 metres at a cost of US$1.6 million. Reportedly, almost all drill holes intersected uranium mineralization.

From the drill data, a historic resource estimate of 680,000 tonnes grading 0.075% U3O8 plus a further 2.7 million tonnes of 0.03% U3O8 was reviewed containing a total of about 1.8 million lbs. of yellowcake. The resource is situated between 100 and 150 metres below surface, with uranium mineralization occurring as a flat-lying, blanket-type supergene enrichment zone within rhyolitic volcanics overlying an intrusive complex.

Geological interpretation, from previous drilling, associates the flat-lying mineralization with the margins of a rhyolite dome complex and with zones of siliceous sinter. The host rock is said to be porous and permeable. Testing indicated uranium recoveries of over 90%, indicating potential for in situ leaching of lower-grade material.

From 1952 to 1966, mining in the district extracted about 250,000 tonnes of ore yielding a reported 1.1 million lbs. of U3O8. Operations primarily targeted vertical epithermal veins that cut a sequence of granites, granodiorites and rhyolite ash flow tuffs. Mineralization was mostly oxide (uraninite and pitchblende) although some secondary mineralization occurs as autunite, torbernite and uranophane. Molybdenum mineralization also occurs with the uranium.

With 34.8 million shares outstanding and a recent trading price of 40 per share, Trigon posts a $14-million market capitalization. The shares have traded in a 52-week range of 15-50, with the high coming on announcement of the company establishing a uranium exploration division.