Systematic studies on the zircon U-Pb chronology, whole rock geochemistry and Sr Nd Nd Hf isotope of the southeastern olibogabbro of Wustengoler in the western Kuruktuggi section of Xinjiang have confirmed the origin of the rocks and discussed their tectonic background and geological significance. LA-ICP-MS zircon U-Pb geochronology study shows that the crystallization age of olivine gabbro is 410.3±5.7 Ma （MSWD = 0.56）, which belongs to the Early Devonian magmatic product. All rock geochemistry shows that rocks are characterized by high Al2O3 and CaO, poor alkali, low P2O5 and TiO2 which belongs to low potassium thallus series; In addition, rocks have high Mg# value （72.27～75.04）, obvious Eu positive anomaly （δEu = 1.12～1.38）, LREE are slightly enriched, HREE are relatively gentle; In the trace elements cobweb the rocks are enriched with large ion lithophile elements （Rb, Ba, K, Sr） and Pb, and depleted of high field-strength elements Nb, Ta, P and Ti. The whole rock （87Sr/86Sr）i value （0.703 663～0.704 013） is relatively small, and the range of εNd（t） value （-2.32～+4.98） varies greatly, and the value of zircon εHf（t） is +7.8～+12.5. The comprehensive analysis shows that the magma of rock mass originates from the partial melting of the depleted mantle wedge in the stable area of spinel-lherzolite, which is relatively shallow and has been modified by the subduction plate fluid, and the proportion of the partial melting is between 2%～10%. The magma formed by it has been exposed to a low degree of crustal contamination during the evolution process, and has experienced apocrystalline action of plagioclase and the crystallization of the stone and the weaker olivine and clinopyroxene. Combining with the geological data in the region, this paper suggests that the northern margin of the Tarim has experienced that South Tianshan oceanic subducted towards south in the middle Palaeozoic, and the olivine gabbro is produced on the active continental margin, The growth mode of continental crust during this period was vertical, indicating that the northern margin of Tarim had the property of an accretionary orogenic belt.
Guo Ruiqing Liang Wenbo Liu Guiping Zou Mingyu Hu Xueyuan Wu Huanan Cui Tao Zhang Mengdi. Chronology, geochemical characteristics and geological significance of Early Devonian olivine gabbro in the Kuruktagxi section of Xinjiang[J]. Chinese Journal of Geology, 2020, 55(1): 234-253.