Analysis on the Geochemical Characteristics and Uranium Resourcr Potential of Xuzhuang Granite in Danfeng Area,North Qinling Mountains
The North Qinling is an important granite type uranium deposit area in China.In this paper,Xuzhuang granite and the Malingwa uranium occurrences were selected as the research objects.The uranium metallogenic potential of granite was discussed through systematic study.Xuzhuang granite was found high in Si rich K,Al poor in Ca and Mg.The granite contains a small amount of muscovite,garnet and other minerals with strong aluminum,indicating a typical S-type granite with strong aluminum.The granite may be formed by the partial melting of a crustal mixing source area dominated by metamorphic greywacke and supplemented by argillaceous rocks,which are rich in the large ion elements Rb,Th,U and K,obvious depleted in Sr,Ba,Nb,Ti and slight depleted in P,and strong negative Eu anomaly.Malingwa uranium occurrences is located in the inner contact zone in the west of the pluton.Uranium mineralization is mainly produced in the lithoclastic altered granite,and the ores are highly developed in alteration,which have obvious structural and alteration control characteristics.The mineral assemblage of Malingwa uranium occurrences is of typical endogenetic hydrothermal origin.The favorable factors for uranium mineralization are the rock type(S type)and the high uranium content.Strong tectonic transformation,hydrothermal alteration and superimposed fluids action made the uranium deposited and enriched for mineralization.Combined with abundant surface uranium anomaly information,it was judged that Xuzhuang granite has a good uranium mineralization potential.