Zircon U-Pb age, geochemistry and geological implications of granitoids in Tuerkubantao, Xinjiang

Abstract

Three types of granitoids were recognized in Tuerkubantao(土尔库班套) district, located on the northwestern margin of the Junggar Block. The zircon U-Pb age of the three types of granitoids suggests that they formed in different orogenic stage in response to the convergence and collision between Siberian and Kazakhstan plates. Biotite granite is similar to the volcanic arc granites in composition, with zircon U-Pb age of 382.8±2.5 and 355.6±2.4 Ma. The former is crystallizing age of the volcanic arc granite, while the later record the time of hydrothermal alteration induced by a later magmatism. The granite is severe altered and its zircon grain get a lower intercept age of 324.4±7.3 Ma, which is possibly coursed by magmatism in syn-collision. The rhyolite with composition similar to A-type granites in adjacent area, crystallized at 295.9±1.4 Ma, is possibly the extrusive phase of A-type granite formed in the post-orogenic tectonic setting. The granitoids in Tuerkubantao area record the evolution of the northwestern Junggar orogen. The area has been in convergence setting from Middle to Late Devonian, and stepped into syn-collisional tectonic setting in Early Carboniferous, finally evolved into the post-orogenic tectonic stage since Early Permian.

Keywords

zircon U-Pb age / granitoid / orogen evolution / Tuerkubantao

References

[1] Batchelor R A, Bowden P. Petrogenetic Interpretation of Granitoid Rock Series Using Multicationic Parameters. Chemical Geology, 1985, 48(1–4): 43-55.

[2] Black R, Liegeois J P. Cratons, Mobile Belts, Alkaline Rocks and Continental Lithospheric Mantle: The Pan-African Testimony. Journal of the Geological Society, 1993, 150: 89-98.

[3] Coleman R G. Continental Growth of Northwest China. Tectonics, 1989, 8(3): 621-635.

[4] Eby G N. Chemical Subdivision of the A-Type Granitoids: Petrogenetic and Tectonic Implications. Geology, 1992, 20(7): 641-644.

[5] Evensen N M, Hamilton P J, O’Nions R K. Rare-Earth Abundances in Chondritic Meteorites. Geochimica et Cosmochimica Acta, 1978, 42(8): 1199-1212.

[6] Feng Y, Coleman R G, Tilton G, . Tectonic Evolution of the West Junggar Region, Xinjiang, China. Tectonics, 1989, 8(4): 729-752.

[7] Jahn B M, Windley B, Natal’in B, . Phanerozoic Continental Growth in Central Asia. Journal of Asian Earth Sciences, 2004, 23(5): 599-603.

[8] Long L L, Wang J B, Wang Y W, . Geochronology and Geochemistry of the Ore-Bearing Porphyry in Xilekuduke Cu-Mo Deposit, Fuyun Area, Xinjiang, China. Geological Bulletin of China, 2009, 28(12): 1840-1851.

[9] Mendes J C, Avila C A, Pereira R M, . 207Pb/206Pb-Ages of Zircons from Syn-Collisional I-Type Prophyritic Granites of the Central Ribeira Belt, SE Brazil. Gondwana Research, 2006, 9(3): 326-336.

[10] Pearce J A, Harris N B W, Tindle A G. Trace Element Discrimination Diagrams for the Tectonic Interpretation of Granitic Rocks. Journal of Petrology, 1984, 25(4): 956-983.

[11] Pei X Z, Li Z C, Ding S P, . Post-Orogenic Granites in Pingwu Region, Northwest Sichuan: Evidence for North China Block and Yangtze Block Collision during Triassic. Journal of Earth Science, 2009, 20(2): 250-273.

[12] Safonova I Y, Buslov M M, Iwata K, . Fragments of Vendian-Early Carboniferous Oceanic Crust of the Paleo-Asian Ocean in Foldbelts of the Altai-Sayan Region of Central Asia: Geochemistry, Biostratigraphy and Structural Setting. Gondwana Research, 2004, 7(3): 771-790.

[13] Sengör A M C, Natal’in B A, Burtman V S. Evolution of the Altaid Tectonic Collage and Paleozoic Crustal Growth in Eurasia. Nature, 1993, 364(6453): 299-307.

[14] Shen X M, Zhang H X, Wang Q, . Late Devonian-Early Permian A-Type Granites in the Southern Altay Range, Northwest China: Petrogenesis and Implications for Tectonic Setting of “A2-Type” Granites. Journal of Asian Earth Sciences, 2011, 42(5): 986-1007.

[15] Silver L T, Deustch S. Uranium-Lead Isotopic Variations in Zircons: A Case Study. The Journal of Geology, 1963, 71(6): 721-758.

[16] Steiger R H, Jäger E. Subcommission on Geochronology: Convention on the Use of Decay Constants in Geo- and Cosmochronology. Earth Planetary Science Letters, 1977, 36: 359-362.

[17] Sun S S, McDonough W F. Saunders A D, Norry M J. Chemical and Isotopic Systematics of Oceanic Basalts: Implications for Mantle Composition and Processes. Magmatism in the Ocean Basins, 1989 London, Special Publication: Geological Society, 313-345.

[18] Sylvester P J, Ghaderi M. Trace Element Analysis of Scheelite by Excimer Laser Ablation Inductively Coupled Plasma Mass Spectrometry (ELA-ICP-MS) Using a Synthetic Silicate Glass Standard. Chemical Ceology, 1997, 141(1–2): 49-65.

[19] Vavra G, Gebauer D, Schmid R, . Multiple Zircon Growth and Recrystallization during Polyphase Late Carboniferous to Triassic Metamorphism in Granulites of the Ivrea Zone. (Southern Alps): An Ion Microprobe (SHRIMP) Study. Contributions to Mineralogy and Petrology, 1996, 122(4): 337-358.

[20] Vavra G, Schmid R, Gebauer D. Internal Morphology, Habit and U-Th-Pb Microanalysis of Amphibolite-to-Granulite Facies Zircons: Geochronology of the Ivrea Zone (Southern Alps). Contributions to Mineralogy and Petrology, 1999, 134(4): 380-404.

[21] Wang T, Jahn B M, Kovach V P, . Nd-Sr Isotopic Mapping of the Chinese Altai and Implications for Continental Growth in the Central Asian Orogenic Belt. Lithos, 2009, 110(1–4): 359-372.

[22] Wang Y W, Wang J B, Wang L J, . The Tuerkubantao Ophiolite Mélange in Xinjiang, NW China: New Evidence for the Erqis Suture Zone. Geoscience Frontiers, 2012, 3(5): 1-16.

[23] Whalen J B, Currie K L, Chappell B W. A-Type Granites: Geochemical Characteristics, Discrimination and Petrogenesis. Contributions to Mineralogy and Petrology, 1987, 95(4): 407-419.

[24] Xia X P, Sun M, Zhao G C, . Spot Zircon U-Pb Isotope Analysis by ICP-MS Coupled with a Frequency Quintupled (213 nm) Nd-YAG Laser System. Geochemical Journal, 2004, 38: 191-200.

[25] Xiao W J, Windley B F, Badarch G, . Palaeozoic Accretionary and Convergent Tectonics of the Southern Altaids: Implications for the Growth of Central Asia. Journal of the Geological Society, 2004, 161(3): 339-342.

[26] Xiao W J, Windley B F, Yuan C, . Paleozoic Multiple Subduction-Accretion Processes of the Southern Altaids. American Journal of Science, 2009, 309(3): 221-270.

[27] Xue C J, Zhao Z F, Wu G G, . The Multiperiodic Superimposed Porphyry Copper Mineralization in Central Asian Tectonic Region: A Case Study of Geology, Geochemistry and Chronology of Halasu Copper Deposit, Southeastern Altai, China. Earth Science Frontiers, 2010, 17(2): 53-82.

[28] Yang W P, Zhang Z C, Zhou G, . The Discovery and Implications of the Xileketehalasu Porphyry Copper Deposit in South Margin of Altay Copper Deposit Belt. Geology in China, 2005, 32(1): 207-114.

[29] Zhang H X, Shen X M, Ma L, . Geochronology of the Fuyun Adakite, North Xinjiang and Its Constraint to the Initiation of the Paleo-Asian Ocean Subduction. Acta Petrologica Sinica, 2008, 24(5): 1054-1058.

[30] Zhang Z C, Mao J W, Cai J H, . Geochemistry of Picrites and Associated Lavas of a Devonian Island Arc in the Northern Junggar Terrane, Xinjiang (NW China): Implications for Petrogenesis, Arc Mantle Sources and Tectonic Setting. Lithos, 2008, 105(3–4): 379-395.

[31] Zhang Z C, Yan S H, Chen B L, . SHRIMP U-Pb Dating for Subduction Related Granites in North Junggar, Xinjiang. Chinese Science Bulletin, 2006, 51(13): 1565-1574.

[32] Zhou T F, Yuan F, Tan L G, . Geodynamic Significance of the A-Type Granite in the Sawuer Region in West Junggar, Xinjiang: Rock Geochemistry and SHRIMP Zircon Age Evidence. Science in China Series D: Earth Sciences, 2006, 49(2): 113-123.

[33] Zhu Y F, Song B. Petrology and SHRIMP Chronology of Mylonitized Tianger Granite, Xinjiang: Also about the Dating on Hydrothermal Zircon Rim in Granite. Acta Petrologica Sinica, 2006, 22(1): 135-144.