Geochemical Characteristics And Tectonic Significance Of Mafic Dyke Swarm In Mayer Kangri Of Northen Tibetan Qiangtang

Tibet qiangtang region is important to research the evolution of the ancient tethysregion, the research area is located in the LongMuCuo-ShuangHu suture zone ofcentral qiangtang, LongMuCuo-ShuangHu suture zone is believed to be important toresearch the evolution of the ancient tethys tectonic belt, hence making clearly thenature of LongMuCuo-ShuangHu tectonic belt is important to research on theevolution process of the ancient tethys ocean. The author conducted a samplingresearch with east-west mafic dyke swarm in the Mayer Kangri of qiangtang central,and measured a geological section in the research area, through the testing andanalysis of the east-west rock data, data processing, combining previous researchachievements on the area, a summary of the main result of this study are as follows:1,The mian rocks of east-west mafic dyke swarm in Mayer Kangri aregabbro,diabase,gabbro,diabase, rocks have different degrees of alteration happened.Rock classification is the alkaline basalt, is tholeiite series. main elements TiO2is low,and overall is low titanium type. Low total amount of REE, light REE obviousfractionation, heavy REE content is low. It enriched in Rb, Ba, Th significantly largeion lithophile elements, Nb,Zr high field strength elements relative to other elementsare more losses.2, The geochemical characteristics of the major elements and trace elements and thestructure of the discriminant figure shows east-west gabbro in Mayer Kangri midoutput oceanic ridge basalt (MORB), Magma source area may be from the mixing ofdepleted mantle magma and enrichment mantle magmatic in the magma source area,the process of magma crystallization differentiation has no continental crustcontamination.3, east-west mafic dyke swarm in Mayer Kangri have similar geochemicalcharacteristics with GeMuRi north,LuGu north and GuoGanJiaNianShan. through thetectonic environment discrimination diagram founding that east-west mafic dykeswarm all have MORB characteristics, combined with regional geological relations, the author thinks that east-west mafic dyke swarm in Mayer Kangri and mafic dykeswarm in GeMuRi north,LuGu north and GuoGanJiaNianShan areas are the productof the same age, age of late carboniferous-Permian. East-west mafic dyke swarm inMayer Kangri should be the product of the ancient tethys ocean initial tension, andit is also the evidence of uplift of mafic dyke swarm in LongMuCuo-ShuangHu suturezone between the late carboniferous to early Permian. LongMuCuo-ShuangHu suturezone has a wide distribution of basite era, as the earliest in the ordovician, the latest inlate Triassic.