Geology

The Cisneros Project is underlain by an intrusive body of granodiorite to quartz diorite composition, the Antioquia Batholith In the project area, the batholith is cut by two fault systems trending northwest and east-northeast.

The Antioquia batholith covers an area of 7,221 km2 and its satellite bodies, a further 322 km2. In the center and eastern part of the province, it is characterized as having lithologic homogeneity with little variation from one place to another. The normal facies have a tonalite and granodiorite composition and present subordinate facies, one felsic and the other gabbroic.

The shape of the batholith is trapezoidal, unlike other great plutons that extend in the regional tectonic direction and it is characterized by its petrographic and petrochemical homogeneity. It has discordant contacts with encasing rocks, generally intrusive rocks with aureoles contact development, of varied extension and magnitude, in pyroxene hornblende to albita-epidote hornblende facies. Very little deformation can be attributed to its intrusion; there are no changes in the shape or intensity of the encasing rock's deformation. The intrusive rock does not deflect the regional folding but instead truncates them and for that reason the pitch on the metamorphic or sedimentary rocks of San Luis vary little or nothing as they approach contact with the intrusive rock.