摘要
The Emeishan ( ~260Ma ), Siberian ( ~250Ma ) and Deccan ( ~66Ma ) continental flood basalts are three important Phanerozoic large igneous provinces in the word.Our summation reveals that at least four criteria , which are normally used to identify ancient mantle plumes , are met for these three large igneous provinces :( 1 ) surface uplift prior to magmatism ;( 2 ) Accompanied with continental rifting and breakup events ;( 3 ) Closely linked with the extinction events ;( 4 ) chemical characteristics of plume derived basalts.Although these three large igneous provinces are equally derived from primitive plume sources , there are fundamental differences in geochemical signatures among Emeishan , Siberian and Deccan provinces , reflecting the interaction between the mantle plumes and different upper-mantle reservoirs : ( 1 ) the parental magmas of the Emeishan and Siberian continental flood basalts have undergone , during as- cent , interaction with a source geochemically identical to ancient cratonic lithospheric mantle ( EM1-type source )( 2 ) whereas the crustally ( or lithosphericly ) uncontaminated primitive basalts from the Deccan province display Sr-Nd isotopic variations between plume and EM2geochemical signatures.These differences may control the mineralization potential of the three large igneous provinces.Emeishan and Siberian provinces host world-class magmatic ore deposits whereas no significant deposits have been found from the Deccan.