On Metallogenic Process Of Jinchuan Ni-Cu-(PGE) Sulfide

Jinchuan mafic rock intrusions, which are consisted ofⅢ、I、ⅡandⅣfour Mining Areas, located at the southwestern margin of Alxa massif in China, They are mainly comprised of Lherzolire, olivine, pyroxene,hornblende and plagioclase are the main petrogenic minerals. The pair minerals are magnetite, titanium ore and spinel.The characteristics of petrology, mineralogy and geochemistry on these intrusions are investigated for the metallogenic processes. The following results have been obtained.(1) The m/f ratio of the intrusion fall into the range of ferrous-ultramafic rocks.The intrusion is featured by low Ti, low total alkalis and low Al2O3. The primary magama is picritic tholeiite which is from low degree partial melting of mantal.(2) most samples have high LREE/HREE rations, enrich in LELES, relatively deplete in HFSE (Nb,Ta).(3) The comparison of SPGE and (Pt+Pd+Rh)/(Os+Ir+Ru) among the NO.24, NO.1 and NO.2 ore bodys indicate that the NO.2 ore body is not from the same intrusion.(4) element geochemistry characters indicate that the magma experienced contamination.The main dark-colored minerals are clinopyxene in the processes of the fractional crystallization and the condense of plagioclase. The crystallization of olivine reduce the contence of FeO, and Si increase because of assimilation, lend to the condense of S.(5) Jinchuan Ni-Cu-(PGE) sulfide is a typical Small rock and Large deposit, the ore-forming process of is the deep-seated magmatic liquation-injection mineralization.