Characteristics Research About The Magmatite Belt In Hood Sheng Gou In The Northern Margin Of Qaidam Basin In Qinghai Province

The study area is located in Wulan County of Qinghai Province, belongs to the northernmargin of Qaidam Basin, and it is located in the junction of Qin-Qi-kun mountains that is thenorthern part of Tibet Plateau. It is a geological body in the boundary fault zone betweenSouth Qilian tectonic belt and Qaidam Basin. Based on the regional geological survey, thetheory of Plate Tectonics and Continental Orogenic Belt, The article focuses on thetemporal and spatial characteristics, petrology, and geochemical characteristics of intrusiverocks(gabbro, diorite, tonalite, syenogranite etc.) in magmatite belt in each period. At last,discusses their tectonic significance.There are four magmatic activities in Hood Sheng Gou magmatite belt that are LateProterozoic, Caledonian, Hercynian and Indosinian magmatic activities.And each magmati-cactivities is close to the corresponding tectonic movements.The lithology is composed ofbasic-neutral-acid complete magmatic sequence transition to the neutral-acidic sequence,andfinally to the only acidic intrusive rocks, and the magma source area has gradually becomeshallow. The rock’s direction of the long axis is NW-W, it is consistent with the direction ofHood Sheng Gou fracture direction and the reginal tectonic line.Hood Sheng Gou fault is a deep fault and has multi period activities, which formed inEarly Proterozoic, until in the Quaternary it is still active. It is the boundary faults ofthe old metamorphic basement in this area, it plays a very important control role onthe intrusive rock, provides onvenient channel for rock-magma. Combined with the geology-cal evolution of the area, the Hood Sheng Gou magmatite belt weld different formationon both sides of the fault zone.So it can be called Hood Sheng Gou magmatite welding zone.We established the magma evolution series of this area，through the comprehensiveanalysis of the temporal and spatial distribution, petrology, geochemistry, isotope chronologyand other aspects of the magmatite. The magma evolution series reflect intrinsic connectionbetween tectonic evolution and magmatism and metamorphism in the northern margin ofQaidam Basin.