This document summarizes uranium exploration results in the Paraná Basin of Paraguay. It provides geological context, including the stratigraphy and tectonic setting. It then describes both historic and current exploration efforts that have identified uranium mineralization, particularly along fault zones, within the San Miguel Formation. Preliminary pumping tests suggest the mineralization could be amenable to in-situ recovery. The results indicate the potential for uranium deposits in the basin.

1. Preliminary uranium
exploration results,
Paraná Basin, Paraguay
Clyde L. Yancey UEC, Albuquerque, NM, USA
Bernard Schmeling Consulting Geophysicist,
Remagen, Germany
Victor Fernandez Crosa UEC, Asunción, Paraguay
Amber Whittaker UEC, Albuquerque, NM, USA
Chelsea Brunner UEC, Albuquerque, NM, USA

2. Outline
• Geologic Setting
• Historic and Current
Exploration
– Coronel Oviedo
– Yuty
• Paragenesis
• Conclusions

3. Geologic Setting: Tectonic Regions of
South America
After Milani and Thomaz-Filho, 2000, and Baretto, 1985

4. Geologic Setting: Eastern Paraguay
After Baretto, 1985, and Dahlkamp, 2010

5. Geologic Setting: Eastern Paraguay
After Baretto, 1985, and Dahlkamp, 2010

6. Geologic Setting: Eastern Paraguay
After Baretto, 1985, and Dahlkamp, 2010

7. Geologic Setting: Eastern Paraguay
After Baretto, 1985, and Dahlkamp, 2010

8. Geologic Setting: Stratigraphic Section
• Alto Paraná Fm
– Alkaline intrusives
• San Miguel Fm
– Deltaic, fluvial, etc.
sandstones (U host)
• Coronel Oviedo Fm
– Glacial, fluvial, and marine
sediments
After Baretto, 1985, and Fulfaro, 1996

9. Geologic Setting: Coronel Oviedo
Concession

10. Geologic Setting: Yuty Concession

11. Historic Exploration: Anschutz
Corporation
• 1976 – 1983 joint venture with:
 Korea Electro Power Company (KEPCO)
 Taiwan Power Company (TPC)
• 162,000 km2 – all eastern Paraguay
• Airborne radiometric and magnetic surveys
• San Miguel Formation
 Massive Sand Unit
 Fine-grained Sand Unit
 Wavy Unit

12. Historic Exploration: Coronel Oviedo

13. Historic Exploration: Yuty

14. Historic Exploration:
Coronel Oviedo Redox Front

15. Historic Exploration: Enigmatic Structure

16. Current Exploration:
Oviedo Carborne Survey South
Data from Schmeling and Paredes Rolon, 2011

17. Current Exploration:
Oviedo Carborne Survey South
Data from Schmeling and Paredes Rolon, 2011

18. Current Exploration:
Oviedo Carborne Survey South
Data from Schmeling and Paredes Rolon, 2011

19. Current Exploration:
Remote Sensing Study

20. Current Exploration:
Remote Sensing Study
Data from Murphy Geological Services, 2011

21. Current Exploration:
Remote Sensing Study

22. Current Exploration:
Remote Sensing Study
Data from Murphy Geological Services, 2012

23. Current Exploration:
Coronel Oviedo
Tres Corrales pumping test
Mineralized zone confined and
saturated
+ 48 gallons/minute yield
= ISR amenability
Similar to S. Texas and Wyoming

24. Current Exploration:
San Antonio Block Model

25. Paragenesis
• Roll front
• South Texas Coastal Plain style of uranium mineralization
• Environment: coastal plain coalescing paleochannels
• Uranium sources:
 Continued leaching of underlying sediments
 Overlying K alkaline intrusives
• Reductants: organic material in sands,
hydrocarbon-related gases
South Texas coastal plain NAIP imagery 2010

26. Summary and Conclusions
• Paraná Basin hosts mineralized strata
– Brazil: Rio Bonito
– Paraguay: San Miguel
• Extensive historic database
• Current exploration results
– Mineralization concentrated along faults
~60mm
– ISR amenable deposits
• Possible re-reduction masking

27. 1970s photo of
Itararé Fm/Coronel Oviedo Fm