Research Tianjun Nanshan Features Of Ophiolite Of Qinghai Province

Tianjun Nanshan in western Qinghai province is located in the North China plate,southern Qilian tectonic belt and the northern margin of the northern margin of the QaidamBasin binding site Zongwulong orogenic belt. Zongwulong orogenic belt is the SouthernQilian block and the northern margin of the Qaidam Basin block in the Paleozoic collisionfunction product，NWW direction linear tectonic belt. Tianjun Nanshan ophiolite in Qinghaiprovince in the study area is not continuously exposed. Each unit of ophiolite in the tectonicrock sheet form occurs in Tianjun Nanshan ophiolitic melange Belt. Ophiolite sequencethroughout the rock recovered is basically intact. Tianjun Nanshan ophiolite belt is about19kilometers long,200~3000meters wide, the exposed area of about25square kilometers.Controlled by faults, the North Larizhaa fault as the boundary with southern Qilian orogenicbelt in the lateTriassic Group Rivers (Tj) contact with in fault. On the south side are in faultcontact with the Carboniferous Guokeshan group(Cgk) clastic rock and carbonate rock strata.Tianjun Nanshan ophiolite assemblages composed of different rock blocks, mainly includingintense serpentinization metamorphosed pure peridotite, peridotite, gabbros, basic lava(deep-sea chert) and siliceous rock.The basalts of Tianjun Nanshan ophiolite belong to calc alkaline rock, with thetholeiiteseries, chemical characteristics of low K and high Ti rocks. The mafic dykes andcumulates gabbros basic lava rock with the same chemical characteristics. Metamorphic ultrabasic have peridotite features of typical ophiolite in, their common geochemicalcharacteristics reflecting that they are members of the same ophiolite suite in the family. Thedifferent rock combination product formation belongs to the same tectonic environment.Tianjun Nanshan ophiolite total content of REE is low. Metamorphic peridotite is thelowest, the total REE is slightly high or close to mid ocean ridge ophiolite. REE line is notexactly the same of mid ocean ridge ophiolite. The REE line is close to ocean island ophiolite.Trace elements are generally enriched in LIL elements, but loss of HFS elements.The ophiolite mafic lava and mafic dyke swarms of87Sr/86Sr (0.7037~0.703852) ratio is closeto the ratio of typical ocean island basalt, and slightly higher than the ratio of oceanicridge basalt.Tianjun Nanshan ophiolite and its tectonic emplacement time should be in the early andMiddle Carboniferous, which is consistent with the formation of the age limit. From thegeological features, petro chemistry and geochemistry characteristics reflect the intracontinental rift expansion of the Late Carboniferous is small ocean task environment. Itsfound that the new understanding of Zongwulong orogenic belt mechanism of geologicalattributes, geodynamic, providing a new basis for tectonic relationship with the Qilianorogenic belt, The northern margin of the Qaidam Basin Basin massif and research Gut Tisocean evolution.