Paraguay is not often associated with mining or exploration, but its Government has recently passed a new mining law similar to those in the USA and Australia, reports Wildhorse Energy. WildHorse has been awarded a concession covering 3,500 km2 in the Parana Basin, Paraguay, granting the company the rights to immediately commence a planned exploration programme.
The concessions contain known uranium mineralisation, based on historical exploration. Subject to the successful completion of exploration, WildHorse has the right to convert its concession to a mining permit. WildHorse Managing Director, Richard Pearce said the company had pursued the Paraguayan asset because, like its other assets in the US and Hungary (see International Mining Project News, September 3 issue), it is a substantial set of projects with extensive drilling and other data.
This region of South America also has a history of uranium mine operation, with established mines in nearby regions of Brazil and Argentina, and a nuclear power industry that is set to expand rapidly. Wildhorse reports that companies such as Cue Capital and Crescent Resources are already active in Paraguay and Globe Uranium and Mega Uranium have extensive exploration programs in Argentina in the same geological region.
Pearce said over the next six months the company would evaluate the extensive historical data on its new Paraguayan concession. “From this review, we aim to evaluate several potential targets, each with significant potential.”
Between 1978 and 1981, a private Denver based, American company, Anschutz acquired the exploration rights to the eastern third of Paraguay for the purpose of exploration for sedimentary hosted uranium deposits. Anschutz selected the huge Parana Basin of Paraguay as it had the same characteristics as Wyoming’s uranium bearing basins, where WildHorse has its advanced projects at Sweetwater and Bison Basin. These sedimentary basin environments are favourable for roll front deposits. Wyoming has produced approximately 190 Mlb of uranium since the late 1950s and still has substantial reserves.
In a Joint Venture with Korea Electric Co (KECO), Anschutz carried out a three-year exploration program, including 42,000 m of drilling. This program comprised extensive field work, including geochemical and geophysical analysis. It identified redox fronts and finally, after spending in the order of $25 million over the three years, Anschutz identified an area with the potential to host a uranium province with the possibility of containing several, 20 Mlb roll front style deposits.
Anschutz completed a total of 34,015 m of rotary drilling and 1,883 m of core drilling in 1981. According to the Annual Summary of Exploration Operations prepared by Anschutz, further drilling in 1982 defined 7 km of roll fronts. Each roll front contained 2 Mlb of U3O8 per km, at a grade of 0.05% U3O8 and 640,000 lb of U3O8 per km of roll front at a grade of 0.14% U3O8. WildHorse has been able to licence this area and believes it has an excellent opportunity to develop a uranium province in the Paraguayan segment of the Parana Basin.
WildHorse is in the process of reviewing the historical data with a view to identifying targets for resource definition drilling. The eastern third of Paraguay is underlain by the western margin of the 1.2 million km2 Parana Basin. The majority of the Parana Basin is located in eastern Brazil and extends southerly into Argentina and Uruguay. Parana is a north-south trending intracratonic basin. The principal target for uranium is the Upper Permo-Carboniferous Independencia Formation in the Basin. The units consist of marine and marginal marine sandstones, shales and conglomerate. Prominent air-radiometric trends, soil and water anomalies occur in these units. Similar rock units on the eastern margin of the Parana Basin, in Brazil, contain uranium resources near the town of Amoranopolis. Younger sedimentary rocks are widespread throughout the old Anschutz concession. These are similar to the aeolian sandstones of Argentina where, at Serra Pintada, a uranium mine produced 2,300 t (5 Mlb) of U3O8 from 1974 through 1986 and has remaining resources of 9,200 t (20 Mlb) U3O8. The grade of that mine is 0.12% U3O8.
