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As a result of the combined interpretation of a gravity study, geological mapping and the lineament analysis of TM Landsat Imagery from the central sector of Extremadura region (Western of Spain), a series of units delimited by gravity alignments have been established confirming that there is an structural setting of the area in blocks. The limits, although irregular, are limited by high density fracture zones, whose intersections may have a major structural and metallogenic interest

As a result of the combined interpretation of a gravity study, geological mapping and the lineament analysis of TM Landsat Imagery from the central sector of Extremadura region (Western of Spain), a series of units delimited by gravity alignments have been established confirming that there is an structural setting of the area in blocks. The limits, although irregular, are limited by high density fracture zones, whose intersections may have a major structural and metallogenic interest

This work is an atempt to characterize different vein sets with W, Sn, U, P (Part II) mineralizations of the Hercynian Massif, studying their internal organization and distribution. One-dimensional analysis of each vein sets has been carried out in Traverses. As a result of a two-dimensional analysys carried out from digitalization of several veins sets, other fractal dimensions as capacity dimension (DJ and mass dimension (Dm) were obtained using Box-counting and Mass aggregation techniques. The later (Dc) and (D ) values support the analysis of vein sets along Traverses in outcrops. The application of this methodology may play an important role in prospectivity of vein-type deposits

The Acoustic Borehole Televiewer (BHTLV) is an important tool for the location of fractures in . boreholes. This technique shows images of oriented fracture planes which can be spatially characterized. The observed fractures have also been studied using spherical statistic, spacing distribution and fractal geometry analysis to asses fracture connectivity. Fractal spacing distribution on fractures and hydraulically active fracture zones have been established in a selected borehole belonging to the El Berrocal Test Site, which is an area that has been studied in an integrated ENRESA-CIEMAT EEC R + D Programm

This work is an atempt to characterize different vein sets with W, Sn, U, P (Part II) mineralizations of the Hercynian Massif, studying their internal organization and distribution. One-dimensional analysis of each vein sets has been carried out in Traverses. As a result of a two-dimensional analysys carried out from digitalization of several veins sets, other fractal dimensions as capacity dimension (DJ and mass dimension (Dm) were obtained using Box-counting and Mass aggregation techniques. The later (Dc) and (D ) values support the analysis of vein sets along Traverses in outcrops. The application of this methodology may play an important role in prospectivity of vein-type deposits

The current research carried out in the El Berrocal Test Site belongs to the Project "Characterization and validation of the radionuclide migration processes under real conditions in a fracture granitic environment ", in order to establish the structural, lithological, geochemical, hydrochemical and hydrogeological aspects of the granite-Uranium mineralization system, to approach the modelling of the U-migration. The geology of the El Berrocal, the statistical, geometrical and kinematic analysis o f the fracturing which affect the El Berrocal granite are shown in this paper

The Acoustic Borehole Televiewer (BHTLV) is an important tool for the location of fractures in . boreholes. This technique shows images of oriented fracture planes which can be spatially characterized. The observed fractures have also been studied using spherical statistic, spacing distribution and fractal geometry analysis to asses fracture connectivity. Fractal spacing distribution on fractures and hydraulically active fracture zones have been established in a selected borehole belonging to the El Berrocal Test Site, which is an area that has been studied in an integrated ENRESA-CIEMAT EEC R + D Programm

D etailed geological mapping o f the granitoids that make this part o f Central Extremadura ( A lb a li and Montanchez stocks) shows different magmatic rocks which have been geochemically characterized using major, trace and REE-elements. Magmatic rocks conform a continuous sequence ranging from granodiorites, tonalites through granites, monzogranites to leucogranites. Leucogranites are homogenous in composition, silica-rich, enriched in Rb, Cs, Ta, Sn, etc. and depleted in Zr, Ba, Sr, Ni, V, Co, LREE (particularly Eu-Eu/Eut-0.07). These characteristics confirm that the leucogranites are the most differentiated rocks of the magmatic sequence and the Sn, W, P, mineralizations are probably related with them. The mineralizing fluids are filling late extensional fractures which are organized in a pattern which is consistent with aHercynian transpressional tectonics

The Gravity map of the Central Extremadura Batholith has been carried out taking and processing 776 field gravity stations supported by eight bases, which are linked to the International Gravity Standardization Net (IGSN-71) through the BF-16 (Cáceres) Base which belongs to the “Red de Gravimetría Fundamental Española" (RGF-73). The Geodetic Reference System (GRS-67) has been utilized for all the calculations including the theorethical gravity value. The Bouguer Anomaly Map shows the main geological and structural characteristics of the study area, improving the general knowledge of the Central Extremadura Region. The support of the gravity in order to understand the shape of the granitic bodies and the relationships with the mineralizations are enhanced in this study

The Gravity map of the Central Extremadura Batholith has been carried out taking and processing 776 field gravity stations supported by eight bases, which are linked to the International Gravity Standardization Net (IGSN-71) through the BF-16 (Cáceres) Base which belongs to the “Red de Gravimetría Fundamental Española" (RGF-73). The Geodetic Reference System (GRS-67) has been utilized for all the calculations including the theorethical gravity value. The Bouguer Anomaly Map shows the main geological and structural characteristics of the study area, improving the general knowledge of the Central Extremadura Region. The support of the gravity in order to understand the shape of the granitic bodies and the relationships with the mineralizations are enhanced in this study

D etailed geological mapping o f the granitoids that make this part o f Central Extremadura ( A lb a li and Montanchez stocks) shows different magmatic rocks which have been geochemically characterized using major, trace and REE-elements. Magmatic rocks conform a continuous sequence ranging from granodiorites, tonalites through granites, monzogranites to leucogranites. Leucogranites are homogenous in composition, silica-rich, enriched in Rb, Cs, Ta, Sn, etc. and depleted in Zr, Ba, Sr, Ni, V, Co, LREE (particularly Eu-Eu/Eut-0.07). These characteristics confirm that the leucogranites are the most differentiated rocks of the magmatic sequence and the Sn, W, P, mineralizations are probably related with them. The mineralizing fluids are filling late extensional fractures which are organized in a pattern which is consistent with aHercynian transpressional tectonics