Resumen

BERG, Talía C.; ECHEVARRIA, Pablo J.  y  RE KUHL, Guillermo E.. Uranium exploration through the integration of Multispectral Imagery, Radar and Field Radiometry at the Laguna Sirven Project, Province of Santa Cruz. Ser. correl. geol. [online]. 2017, vol.33, n.2, pp.1-10. ISSN 1666-9479.

The present publication details the works carried out for the delimitation of uranium anomalies in the Laguna Sirven Project, north of Santa Cruz Province. During the 70s the CNEA conducted studies aimed at defining areas with potential for uranium mineralization in the provinces of Santa Cruz and Chubut, including this Project. This site corresponds to a sedimentary deposit formed by rich uranium precipitations at the water table interface, creating calcretes of a large extent and typically tabular form. In most of these deposits, uranium comes from the weathering of volcanic rocks, which could be secondary uranium depo-sits. Uranium solubility is closely linked to oxidation potential, whereby under oxidizing conditions uranium is found as U6+ cation, highly soluble and therefore very mobile. However, in a reducing environment, the U6+ ion is converted into the insoluble form U4+. Thus, the uranium in solution fows through permeable strata until it meets reducing conditions and precipitates. Geochemically, uranium is an incompatible element, which causes it to be one of the latest elements in crystallizing from a magmatic fuid. Therefore, it concentrates in acid rocks formed at the final stages of magmatic differentiation. It is estimated that, in the deposit model, the primary source of uranium is the Cretaceous pyroclastites from Castillo, Bajo Barreal and Laguna Palacios formations, belonging to the Chubut Group, and to a lesser extent the Jurassic pyroclastites from Bahía Laura Group. The studies conducted through remote sensing were based on LandSat 7 ETM+ and ASTER multispectral images, and Digital Elevation Models from SRTM images. Many products were generated from this image data set oriented to the delimitation of mineral and thermal anomalies, runoff patterns, source and deposition areas. Afiterward, feldwork was performed in the area, including a gamma radiospectrometry terrestrial survey and geobotanical sampling. The integration of all the information obtained into a Geographic Information System allowed us to move forward in exploratory works in this Project.

Palabras clave : Uranium. Laguna Sirven. Satellite imagery. Gamma radiospectrometry..

        · resumen en Español     · texto en Español     · Español ( pdf )