Genetic Types, Metallogenic Rules and Series of Metallic Depositsaround Qaidam Basin

The area around Qaidam basin in the northeastern Qinghai-Tibetan Plateau,located within the intersection between paleo-Asia and Tethyan tectonic domains,is a multiple orogen which underwent a very complicated evolutionary process,and is also a very important and potential metallogenic belt in China.Based on comprehensive analyses,the metallogenic setting,tectonic evolution,major deposit types,regional metallogenic rules and series in this area are described briefly in this paper.This area underwent four tectonic cycles including Precambrian old land formation,early Paleozoic orogenic activity,late Paleozoic-early Mesozoic orogenic process and Cenozoic overlap orogenic process.Of these,early Paleozoic and late Paleozoic-early Mesozoic orogenic activities were related genetically to metallic mineralization.Six types of deposits are recongnized including VMS and SEDEX types belonging to sedimentary exhalative deposit assemblage,and porphyry,skarn,hydrothermal vein and orogenic gold deposit belonging to orogenic deposit assemblage.The metallic mineralization is characterized by multiperiod,multi-elements and multistyles.Five metallogenic series of metallic deposits in the area are concluded,i.e.Cu-polymetallic deposit metallogenic series related to late Proterozoic-Cambrian splitting,Cu-Co-Pb-Zn polymetallic deposit metallogenic series related to Ordovician-Silurian splitting,Au-polymetallic deposit metallogenic series related to late Caledonian collision,Cu-polymetallic deposit metallogenic series related to late Paleozoic splitting and Fe-Cu-Pb-Zn-Au polymetallic deposit metallogenic series related to late Variscan-Indosinian orogenic activity.