Las mineralizaciones de U de la Carretona y Casa del Gallo En el granito de Albala (Cáceres).

Resumen

The U mineralizations that are estudied in this paper are hosted in Albalágranite. They are controled by late Hercinian vertical or subvertical faults, with an aproximate orientation of N30°E. The mineral association in them comprises pichblenda, coffinite, blackoxides, piryte mar casite,melnicovite and some sphalerite in La Carretona, and black oxides, pyríte and melnicovite in Casa del Gallo. In both cases the gangue is made up of quartz, jasper and apatite. The origin of the uranium that gives rise to these mineralizations comes from the remobilizations of this element present in the host granite, basically in the form of uraninite, as a consequence of the early hydrothermal weathering of these granites, which occurred during,discontinuous proceses and supergenic weathering .Hence, we suggest that the first mineralizing process of the uranium took place during the sub-solid state of the granite, as a consequence of the leaching of U due to late hydrothermal fluids during the Permian Period. the posibility of a remobilization of U during the late alpinefracturation cannot be excluded. Finally, from the end of the tertiary to the present the latest stage of weathering and a concentration of the U have occurred, forming the hexavalent minerals.