TY - JOUR A1 - Llorens,T. A1 - Moro,M.C. T1 - Oxide minerals in the granitic cupola of the Jalama Batholith, Salamanca, Spain. Part I: accessory Sn, Nb, Ta and Ti minerals in leucogranites, aplites and pegmatites JF - Journal of Geosciences JA - J. Geosci. Y1 - 2012 VL - 57 IS - 1 SP - 25 EP - 43 CY - Prague PB - Czech Geological Society SN - 1803-1943 (online), 1802-6222 (print) AV - Free UR - http://dx.doi.org/10.3190/jgeosci.113 L1 - http://www.jgeosci.org/content/jgeosci.113_llorens.pdf KW - Jalama Batholith KW - pegmatite dikes KW - cassiterite KW - columbite-group minerals AB - Sn-Nb-Ta-Ti oxides occur as accessory minerals in the granitic facies of the External Unit in the Jalama Batholith (Salamanca, Spain) and in the related LCT pegmatite dikes of the rare-element class. Moreover, abundant cassiterite and columbite-group minerals crystallized in the Cruz del Rayo peribatholithic pegmatite dikes, cutting the pre-Ordovician low-grade metasedimentary rocks of the surrounding Schist-Graywacke Complex.Cassiterite, rutile, ilmenite and tantalite-(Fe) occur disseminated in the border facies of the External Unit, especially throughout the tourmaline-bearing leucogranite and the apical aplites. Additionally, cassiterite, rutile and Ta-rich rutile developed locally in the intragranitic pegmatite dikes. Two types of peribatholithic pegmatites can be distinguished at Cruz del Rayo: (i) granite-like pegmatites, with columbite-(Fe) I and II and cassiterite, in which the influence of metasomatic fluids led to formation of the late albite unit and crystallization of tantalite-(Fe), and (ii), greisen-like bodies, which contain high amounts of columbite-(Fe), columbite-(Mn), tantalite-(Mn) I and II as well as cassiterite. The primary oxide assemblage in both types of the peribatholithic pegmatite dikes would have crystallized as a result of magmatic differentiation of the residual melts coming from the Jalama granitic cupola. However, crystallization of the secondary assemblage, richer in Fe and Ta, is interpreted mainly as a consequence of interaction with external fluids coming from the metamorphic host rocks, more or less mixed with meteoric fluids, although partial dissolution and re-precipitation could also have played an important role, as well. ER -