Mafic-ultramafic Intrusions in Beishan and Eastern Tianshan at Southern CAOB: Petrogenesis, Mineralization and Tectonic Implication

The widespread mafic-ultramafic complexes in the Earth are well-known as their hosting Ni-Cu-PGE ore deposits, and their petrogenesis and mineralization have become hot issues in the geological studies. This thesis comprehensively investigated the petrology, mineralogy, geochemistry and geochronology of several mafic-ultramafic complexes in the Beishan Terrane, southern Central Asian Orogenic Belt aimed at systematically determining the mineralization and petrogenetic processes responsible for the formation of the complexes and placing constraints on the tectonic evolution of the Eastern Tianshan and Beishan, and the Early Permian mantle plume. The thesis identified mineralizing indicators of Ni-Cu sulfide deposits and defined the roles of partial melting, fractional crystallization, crustal assimilation and magma injection. The systematical isotopic compositions revealed the mantle source of the mafic-ultramafic complexes had undergone the subduction-related modifications both from the South Tianshan Ocean and subsequently the Junggar Ocean, and that the complexes were emplaced in the period of 269-285 Ma coeval with the 280 Ma mantle plume event in the Tarim Craton. The results of this thesis provide new insights about the tectonic setting, magma evolution, ore genesis, and exploration implications of the mafic-ultramafic complexes in Central Asian Orogenic Belt. Dr. Benxun Su works at the Institute of Geology and Geophysics, Chinese Academy of Sciences, China.

2010 Prize of President Scholarship for Postgraduate Students
2010 Lisiguang Award for Excellent Ph.D student
2010 GUCAS-BHP Billiton Scholarship
2012 Outstanding Doctoral Dissertation Awards, Chinese Academy of Sciences, China
2012 Outstanding Ph.D Thesis, Beijing
2012 Xiangjiang Scholar, University of Hong Kong

Publications:
25 Su, B.X., Qin, K.Z., Santosh, M., Sun, H., Tang, D.M., 2013. The Early Permian mafic-ultramafic complexes in the Beishan Terrane, NW China: Alaskan-type intrusives or rift cumulates? Journal of Asian Earth Sciences 66(4), 175-187.
24 Su, B.X., Qin, K.Z., Tang, D.M., Sakyi, P.A., Liu, P.P., Sun, H., Xiao, Q.H., 2013. Late Paleozoic mafic-ultramafic intrusions in southern Central Asian Orogenic Belt (NW China): insight into magmatic Ni-Cu sulfide mineralization in orogenic setting. Ore Geology Reviews 51(2), 57-73.
23 Su, B.X., Zhang, H.F., Ying, J.F., Tang, Y.J., Hu, Y., Santosh, M., 2012. Metasomatized lithospheric mantle beneath Western Qinling, central China: insight into activity of carbonatite melts. The Journal of Geology 120(6), 671-681.
22 Su, B.X., Zhang, H.F., Hu, Y., Santosh, M., Tang, Y.J., Xiao, Y., 2012. The genesis of mantle-derived sapphirine. American Mineralogist 97(5-6), 856-863.
21 Su, B.X., Zhang, H.F., Yang, Y.H., Sakyi, P.A., Ying, J.F., Tang, Y.J., 2012. Breakdown of orthopyroxene contributing to melt pockets in mantle peridotite xenoliths from the Western Qinling, central China: constraints from in situ LA-ICP-MS mineral analyses. Mineralogy and Petrology 104(3), 225-247.
20 Su, B.X., Qin, K.Z., Sun, H., Tang, D.M., Sakyi, P.A., Chu, Z.Y., Liu, P.P., Xiao, Q.H., 2012. Subduction-induced mantle heterogeneity beneath Eastern Tianshan and Beishan: insights from Nd-Sr-Hf-O isotopic mapping of Late Paleozoic mafic-ultramafic complexes. Lithos 134-135(3), 41-51.
19 Su, B.X., Qin, K.Z., Sun, H., Tang, D.M., Xiao, Q.H., Liu, P.P., Sakyi, P.A., 2012. Olivine compositional mapping of mafic-ultramafic complexes in Eastern Xinjiang (NW China): Implications for mineralization and tectonic dynamics. Journal of Earth Science 23(1), 41-53.
18 Su, B.X., Zhang, H.F., Deloule, E., Sakyi, P.A., Xiao, Y., Tang, Y.J., Hu, Y., Ying, J.F., Liu, P.P., 2012. Extremely high Li and low δ7Li signatures in the lithospheric mantle. Chemical Geology 292-293, 149-157.
17 Su, B.X., Qin, K.Z., Sakyi, P.A., Malaviarachchi, S.P.K., Liu, P.P., Tang, D.M., Xiao, Q.H., Sun, H., Ma, Y.G., Mao, Q., 2012. Occurrence of an Alaskan-type complex in the Middle Tianshan Massif, Central Asian Orogenic Belt: Inferences from petrological and mineralogical studies. International Geology Review 54(3), 249-269.
16 Su, B.X., Qin, K.Z., Sakyi, P.A., Tang, D.M., Liu, P.P., Malaviarachchi, S.P.K., Xiao, Q.H., Sun, H., 2012. Geochronologic-petrochemical studies of the Hongshishan mafic-ultramafic intrusion, Beishan area, Xinjiang (NW China): petrogenesis and tectonic implications. International Geology Review 54(3), 270-289.
15 Su, B.X., Qin, K.Z., Tang, D.M., Deng, G., Xiao, Q.H., Sun, H., Lu, H.F., Dai, Y.C., 2011. Petrological features and implications for mineralization of the Poshi mafic-ultramafic intrusion in Beishan area, Xinjiang. Acta Petrologica Sinica 27(12), 3627-3639.
14 Su, B.X., Qin, K.Z., Sakyi, P.A., Li, X.H., Yang, Y.H., Sun, H., Tang, D.M., Liu, P.P., Xiao, Q.H., Malaviarachchi, S.P.K., 2011. U-Pb ages and Hf-O isotopes of zircons from Late Paleozoic mafic-ultramafic units in southern Central Asian Orogenic Belt: tectonic implications and evidence for an Early-Permian mantle plume. Gondwana Research 20(2-3), 516-531.
13 Su, B.X., Qin, K.Z., Sakyi, P.A., Liu, P.P., Tang, D.M., Malaviarachchi, S.P.K., Xiao, Q.H., Sun, H., Dai, Y.C., Hu, Y., 2011. Geochemistry and geochronology of acidic rocks in the Beishan region, NW China: petrogenesis and tectonic implications. Journal of Asian Earth Sciences41(1), 31-43.
12 Su, B.X., Zhang, H.F., Sakyi, P.A., Yang, Y.H., Ying, J.F., Tang, Y.J., Qin, K.Z., Xiao, Y., Zhao, X.M., Mao, Q., Ma, Y.G., 2011. The origin of spongy texture of mantle xenolith minerals from the Western Qinling, Central China. Contributions to Mineralogy and Petrology 161(3), 465-482.
11 Su, B.X., Zhang, H.F., Tang, Y.J., Chisonga, B., Qin, K.Z., Ying, J.F., Sayki, P.A., 2011. Geochemical syntheses among the cratonic, off-cratonic and orogenic garnet peridotites and their tectonic implications. International Journal of Earth Sciences 100(4), 695-715.
10 Su, B.X., Zhang, H.F., Sakyi, P.A., Qin, K.Z., Liu, P.P., Ying, J.F., Tang, Y.J., Malaviarachchi, S.P.K., Xiao, Y., Zhao, X.M., Mao, Q., Ma, Y.G., 2010. Formation of melt pockets in mantle peridotite xenoliths from the Western Qinling (Central China): partial melting and metasomatism. Journal of Earth Science 21(5), 641-668.
9 Su, B.X., Zhang, H.F., Sakyi, P.A., Qin, K.Z., Tang, Y.J., Ying, J.F., Xiao, Y., 2010. Garnet-spinel transition in the upper mantle: review and interpretation. Journal of Earth Science 21(5), 635-640.
8 Su, B.X., Zhang, H.F., Sakyi, P.A., Ying, J.F., Tang, Y.J., Yang, Y.H., Qin, K.Z., Xiao, Y., Zhao, X.M., 2010. Compositionally stratified lithosphere and carbonatite metasomatism recorded in mantle xenoliths from the Western Qinling (Central China). Lithos 116(1-2), 111-128.
7 Su, B.X., Qin, K.Z., Sun, H., Wang, H., 2010. Geochronological, petrological, mineralogical and geochemical studies of the Xuanwoling mafic-ultramafic intrusion in Beishan area, Xinjiang. Acta Petrologica Sinica 26(11), 3283-3294.
6 Su, B.X., Zhang, H.F., Ying, J.F., Xiao, Y., Zhao, X.M., 2009. Nature and processes of the lithospheric mantle beneath the western Qinling: evidence from deformed peridotitic xenoliths in Cenozoic kamafugite from Haoti, Gansu Province, China. Journal of Asian Earth Sciences 34(3), 258-274.
5 Su, B.X., Qin, K.Z., Sun, H., Tang, D.M., Qiao, Q.H., Cao, M.J., 2009. Petrological and mineralogical characteristics of Hongshishan mafic-ultramafic complex in Beishan area, Xinjiang: implications for assimilation and fractional crystallization. Acta Petrologica Sinica 25(4), 873-887.
4 Su, B.X., Zhang, H.F., Wang, Q.Y., Sun, H., Xiao, Y., Ying, J.F., 2007. Spinel-garnet phase transition zone of Cenozoic lithospheric mantle beneath the eastern China and western Qinling and its T-P condition. Acta Petrologica Sinica 23(6), 1313-1320.
3 Su, B.X., Zhang, H.F., Xiao, Y., Zhao, X.M., 2006. Characteristics and geological significance of olivine xenocrysts in Cenozoic volcanic rocks from western Qinling. Progress in Natural Science 16(12), 1300-1306.
2 Su, B.X., Chen, Y.L., Liu, F., Wang, Q.Y., Zhang, H.F., Lan, Z.W., 2006. Geochemical characteristics and significance of Triassic sandstones of Songpan-Ganze block. Acta Petrologica Sinica 22(4), 961-970.
1 Su, B.X., Chen, Y.L., Lan, Z.W., Liu, F., Zhang, H.F., Wang, Q.Y., 2005. Sedimentary and geochemical study on the Precambrian-Triassic series of Songpan-Ganze block. Acta Sedimentologica Sinica 23(3), 437-446.