U-Pb zircon dating of Early Paleozoic gabbro from the Nantinghe ophiolite in the Changning-Menglian suture zone and its geological implication

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• 作者：BaoDi Wang (15481)
  LiQuan Wang (15481)
  GuiTang Pan (15481)
  FuGuang Yin (15481)
  DongBing Wang (15481)
  Yuan Tang (15481)
  
• 关键词：Changning ; Menglian suture zone ; Longmu Co ; Shuanghu suture zone ; Nantinghe ; Early Paleozoic ; cumulative gabbro
• 刊名：Chinese Science Bulletin
• 出版年：2013
• 出版时间：March 2013
• 年：2013
• 卷：58
• 期：8
• 页码：920-930
• 全文大小：1646KB
• 参考文献：1. Liu B P. The Sedimentary Geology of Ancient Continental Margin (in Chinese). Wuhan: Chinese Geology University Press, 1992. 1-11
  2. Liu B P, Feng Q L, Fang N Q, et al. Tectonic evolution of Palaeo-Tethys Poly-island-ocean in Changning-Menglian and Lancangjiang belts, Southwestern Yunnan, China (in Chinese). Earth Sci-J Chin Univ Geosci, 1993, 18: 529-39
  3. Zhong D L, Wu G Y. The discovery of ophiolite in southeastern Yunnan (in Chinese). Chin Sci Bull (Chin Ver), 1998, 43: 1365-370
  4. Cui C L, Zeng Y F, Duan L L, et al. Is there a Late Paleozoic great ocean in Changning-Menglian belt, Western Yunnan, China? (in Chinese). Acta Sed Sin, 1999, 17: 176-82
  5. Mo X X, Shen S Y, Zhu Q W. The Volcanic Rocks-the Ophiolite and Mineralization in Central and Southern Sanjiang Area (in Chinese). Beijing: Geological Publishing House, 1998. 1-28
  6. Metcalfe I. Gondwanaland origin, dispersion, and accretion of East and Southeast Asian continental terranes. J South Am Earth Sci, 1994, 7: 333-47 CrossRef
  7. Shen S Y, Feng Q L, Liu B P, et al. Study on ocean ridge, ocean island volcanic rocks of Changning-Menglian belt (in Chinese). Geol Sci Technol Inf, 2002, 21: 13-7
  8. Zhang Q, Zhou D J, Zhao D S, et al. Wilson cycle of the Paleo-Tethyan orogenic belt in Western Yunnan: Record of magmatism and discussion on mantle processes (in Chinese). Acta Petrol Sin, 1996, 12: 17-8
  9. Yang W Q, Feng Q L, Duan X D. Late Devonian pillow basalt and bedded chert in Chmagning-Mengnma tectonic belt of southwestern Yunnan, China (in Chinese). Geol Bull Chin, 2007, 26: 739-47
  10. Yunnan Institute of Geological Survey. The 1:250000 Regional Geological Survey Report of Fengqing City in the People’s Republic of China (in Chinese). 2008
  11. Liu Y, Hu Z, Gao S, et al. / In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard. Chem Geol, 2008, 257: 34-3 CrossRef
  12. Liu Y, Gao S, Hu Z, et al. Continental and oceanic orust oecycling-induced melt-peridotite interactions in the Trans-North China orogen: U-Pb dating, Hf isotopes and trace elements in zircons from mantle xenoliths. J Petrol, 2010, 51: 537-71 CrossRef
  13. Ludwig K R. User’s manual for Isoplot 3.00: A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center Spec Pub, 2003, 41-0
  14. Chen J, Xu J, Wang B, et al. Origin of Cenozoic alkaline potassic volcanic rocks at KonglongXiang, Lhasa terrane, Tibetan Plateau: Products of partial melting of a mafic lower-crustal source? Chem Geol, 2010, 273: 286-99 CrossRef
  15. Wu Y B, Zheng Y F. The research of zircon mineralogy and constraints on interpretation of U-Pb ages (in Chinese). Chin Sci Bull, 2004, 49: 1589-604
  16. Hoskin P W O, Black L P. Metamorphic zircon formation by solid-state recrystallization of protolith igneous zircon. J Metamorph Geol, 2000, 18: 423-39 CrossRef
  17. Zhai Q G, Wang J, Li C, et al. SHRIMP U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulative gabbro in central Qiangtang, northern Tibetan Plateau. Sci China Ser D-Earth Sci, 2010, 53: 657-64 CrossRef
  18. Zhai Q G, Li C, Huang X P. The Paleo-Tethys ocean in Central Qiangtang, Tibet: Geochemical constraint of mafic rocks from Guoganjianian Mountain (in Chinese). Sci China Ser D-Earth Sci, 2007, 37: 866-72
  19. Zheng Y F. Metamorphic chemical geodynamics in continental subduction zones. Chem Geol, 2012, doi: 10.1016/j.chemgeol.2012. 02.005.
  20. Li W C, Pan G T, Hou Z Q, et al. Metallogenic and Exploration Techniques of Multi-Island-Arc Basin-Collision Orogenic Belt in Southwest the “Three Rivers-(in Chinese). Beijing: Geological Publishing House, 2010. 1-07
  21. Ding L, Zhong D L. Rare earth elements and cerium anomalies characteristics of chert of Paleo-Tethys in Changning-Menglian suture zone, Western Yunnan (in Chinese). Sci China Ser B, 1995, 25: 93-00
  22. Feng Q L, Cui X S, Liu B P. Discovery of late Permian bivalve-fauna from Laochang of Lancang, West Yunnan and its biogeographic characteristics (in Chinese). Earth Sci-J Chin Univ Geosci, 1992, 17: 512-20
  23. Zhang Q, Li D Z. The characteristics of Yidun-type mafic-ultramafic rocks and their comparison with ophiolites (in Chinese). Acta Petrol Sin, 1990, 1990: 33-2
  24. Cong B L, Wu G Y, Zhang Q, et al. Rocks tectonic evolution of Paleo-Tethyan tectonic belt in Western Yunnan, China (in Chinese). Sci China Ser B, 1993, 23: 1201-207
  25. Li P H, Gao R, Cui J W, et al. Paleomagnetic results from the three rivers region, SW China: Implications for the collisional and accretionary history (in Chinese). Acta Geosci Sin, 2005, 26: 387-04
  26. Li P H, Gao R, Cui J W, et al. The palaeomagnetic study of the collision and collage of major landmasses in the Nujiang-Lancangjiang-Jinshajiang area in Western Yunnan and Eastern Xizang (in Chinese). Sed Geol Tethyan Geol, 2003, 23: 28-4
  27. Li C, Zhai Q G, Dong Y S, et al. The discovery of eclogites in Central Qiangtang, Tibet Plateau and its significances (in Chinese). Chin Sci Bull, 2006, 51: 70-4
  28. Li C, Dong Y S, Zhai Q G, et al. Discovery of Eopaleozoic ophiolite in the Qiangtang of Tibet Plateau: Evidence from SHRIMP U-Pb dating and its tectonic implications (in Chinese). Acta Petrol Sin, 2008, 24: 31-6
  29. Wang L Q, Pan G T, Li C, et al. SHRIMP U-Pb zircon dating of Eopaleozoic cumulative in Guoganjianian Mt. from central Qiangtang area of northern Tibet—Considering the evolvement of Proto-and Paleo-Tethys (in Chinese). Geol Bull Chin, 2008, 27: 2045-056
  30. Zhu T X, Zhang Q Y, Dong H, et al. Discovery of the Late Devonian and Late Permian radiolarian cherts in tectonic melanges in the Cedo Caka area, Shuanghu, northern Tibet, China (in Chinese). Geol Bull Chin, 2006, 25: 1413-418
  31. Zhai Q G, Li C, Cheng L R, et al. Geological features of Permian ophiolite in the Jiaomuri area, Qiangtang, Tibet, and its tectonic significance (in Chinese). Geol Bull Chin, 2004, 23: 1228-230
  32. Zhai Q G, Li C, Huang X P. Geochemistry of Permian basalt in the Jiaomuri area, Central Qiangtang, Tibet, China, and its tectonic significance (in Chinese). Geol Bull Chin, 2006, 25: 1419-427
  33. Wang L Q, Li B, Wang B D, et al. 2012. Discovery of Late Silurian volcanic rocks in the Dazhonghe area, Yunxian-Jinggu magmatic arc belt, Western Yunnan, China and its geological significance (in Chinese). Acta Petrol Sin, 2012, 28: 1517-528
  34. Zhu D C, Zhao Z D, Niu Y L, et al. The origin and pre-Cenozoic evolution of the Tibetan Plateau. Gondwana Res, 2012, (in press)
  35. Pan G T, Wang L Q, Ding J, et al. The Geological Map of the Qinghai-Tibet Plateau and Adjacent Areas (1:1500000) (new) (in Chinese). Beijing: Geological Publishing House, 2012
  36. Pan G T, Wang L Q, Zhu D C. Thoughts on some important scientific problems in regional geological survey of the Qinghai-Tibet Plateau (in Chinese). Geol Bull Chin, 2004, 23: 12-9
  
• 作者单位：BaoDi Wang (15481)
  LiQuan Wang (15481)
  GuiTang Pan (15481)
  FuGuang Yin (15481)
  DongBing Wang (15481)
  Yuan Tang (15481)
  
  15481. Chengdu Institute of Geology and Mineral Resources, Chengdu, 610081, China
  
• ISSN：1861-9541

文摘

The Nantinghe ophiolite is located in the northern part of the Changning-Menglian suture zone in southeast Tibet. It is composed of meta-peridotite, cumulative gabbro, meta-gabbro, plagioclase amphibolite and meta-basalt. Zircon U-Pb dating of the cumulative gabbro gives concordant ages of 473.0±3.8 Ma and 443.6±4.0 Ma respectively, indicating the early and late episodes of mafic magmatisms during the Paleo-Tethys oceanic rifting. The 16 LA-ICPMS zircon U-Pb analyses of meta-gabbro yield a weight mean age of 439±2.4 Ma. The gabbro shows relatively low contents of SiO2 (46.46%-2.11%), TiO2 (0.96%-.14%) and K2O (0.48%-.75%). Its trace element distribution patterns are partly similar to those of the mid-ocean ridge basalts, and part is depleted in high field strength elements such as Nb, Ta, Zr, Hf and Ti. These features suggest that the mafic rocks were probably formed in a MORB-like or backarc rift basin setting. The zircon U-Pb age of gabbro is consistent with a late crystallization age of the cumulative gabbro from the Nantinghe ophiolite, suggesting that the Paleo-Tethys oceanic basin was opened during 444-39 Ma, possibly as a backarc basin. It is the first precise age which defines the formation time of the early Paleozoic ophiolite in the Changning-Menglian suture zone. These geochronological and geochemical characteristics of the Nantinghe ophiolite are consistent with those from the Guoganjianianshan and Taoxinghu of the Longmu Co-Shuanghu suture in the Qiangtang region. Thus, we suggest that the both Changning-Menglian and Longmu Co-Shuanghu sutures were probably transformed from the relic oceanic crust of the uniform Paleo-Tethys, which likely represents the original and main Paleo-Tethys oceanic basin.