U–Pb age and Hf isotopes of zircon from basaltic andesite and geochemical fingerprinting of the associated picrites in the Emeishan large igneous province, SW China

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• 作者：Qingyan Tang ; Chusi Li ; Mingjie Zhang ; Yao Lin
• 刊名：Mineralogy and Petrology
• 出版年：2015
• 出版时间：February 2015
• 年：2015
• 卷：109
• 期：1
• 页码：103-114
• 全文大小：7,282 KB
• 参考文献：1. Ali JR, Lo C-H, Thompson GM, Song X (2004) Emeishan basalt Ar–Ar overprint ages define several tectonic events that affected the western Yangtze platform in the Mesozoic and Cenozoic. J Asian Earth Sci 23:163-78 CrossRef
  2. Bai M, Zhong H, Zhu W, Bai Z, He D (2013) Platinum-group element geochemical characteristics of the picrites and high-Ti basalts in the binchuan area, Yunnan province. Acta Geol Sin 87:158-75 CrossRef
  3. Black LP, Kamo SL, Allen CM, Aleinikoff JN, Davis DW, Korsch RJ, Foudoulis C (2003) TEMORA 1: a new zircon standard for phanerozoic U–Pb geochronology. Chem Geol 200:155-70 CrossRef
  4. Chu N-C, Taylor RN, Chavagnac V, Nesbitt RW, Boella RM, Milton JA, German CR, Bayon G, Burton K (2002) Hf isotope ratio analysis using multi-collector inductively coupled plasma mass spectrometry: an evaluation of isobaric interference corrections. J Anal At Spectrom 17:1567-574 CrossRef
  5. Chung S-L, Jahn B-M (1995) Plume-lithosphere interaction in generation of the emeishan flood basalts at the Permian–Triassic boundary. Geology 23:889-92 CrossRef
  6. Chung S-L, Jahn B-M, Genyao W, Lo C-H, Bolin C (1998) The Emeishan flood basalt in SW China: A mantle plume initiation model and its connection with continental breakup and mass extinction at the Permian–Triassic boundary. In: Flower MFJ, Chung S-L, Lo C-H, Lee T-Y (Eds.), Mantle dynamics and plate interactions in East Asia. Am Geophys Union Geodynamic Series 27:47-8
  7. Compston W, Williams IS, Meyer C (1984) U-Pb geochronology of zircons from lunar breccia 73217 using a sensitive high mass-resolution ion microprobe. J Geophys Res 89:525-34 CrossRef
  8. Fan W, Zhang C, Wang Y, Guo F, Peng T (2008) Geochronology and geochemistry of Permian basalts in western Guangxi province, southwest China: evidence for plume–lithosphere interaction. Lithos 102:218-36 CrossRef
  9. Guo F, Fan W, Wang Y, Li C (2004) When did the emeishan mantle plume activity start? geochronological and geochemical evidence from ultramafic-mafic dikes in southwestern China. Int Geol Rev 46:226-34 CrossRef
  10. Hanski E, Walker RJ, Huhma H, Polyakov GV, Balykin PA, Hoa TT, Phuong NT (2004) Origin of the permo–triassic komatiites, northwestern Vietnam. Contrib Mineral Petrol 147:453-69 CrossRef
  11. Hanski E, Kamenetsky VS, Luo Z-Y, Xu Y-G, Kuzmin DV (2010) Primitive magmas in the emeishan large igneous province southwestern China and northern Vietnam. Lithos 119:75-0 CrossRef
  12. He B, Xu Y-G, Huang X-L, Luo Z-Y, Shi Y-R, Yang O-J, Yu S-Y (2007) Age and duration of the emeishan flood volcanism SW China: geochemistry and SHRIMP zircon U–Pb dating of silicic ignimbrites post-volcanic xuanwei formation and clay tuff at the chaotian section. Earth Planet Sci Lett 255:306-23 CrossRef
  13. Hoskin PWO, Schaltegger U (2003) The composition of zircon and igneous and metamorphic petrogenesis. Rev Mineral Geochem 53:27-2 CrossRef
  14. Huang X-L, Niu Y, Xu Y-G, Chen L-L, Yang Q-J (2010) Mineralogical and geochemical constraints on the petrogenesis of post-collisional potassic and ultrapotassic rocks from western Yunnan, SW China. J Petrol 51:1617-654 CrossRef
  15. Kamenetsky VS, Chung S-L, Kamenetsky MB, Kuzmin DV (2012) Picrites from the emeishan large igneous province SW China: a compositional continuum in primitive magmas and their respective mantle
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Mineralogy
  Geochemistry
  
• 出版者：Springer Wien
• ISSN：1438-1168

文摘

The ages of many picrites associated with Permian flood basalts in the Emeishan large igneous province, SW China have been debated for a long time. Some researchers believe that these picrites are co-magmatic with the flood basalts whereas others believe that they are Triassic picritic porphyrites or Cenozoic olivine-rich dikes. We report a U–Pb age of 256.2?±-.4?Ma for the youngest zircon grains from the Binchuan volcanic sequence which contains the disputed picrites. This age is within the range of values reported for the intrusive and extrusive rocks of the Emeishan large igneous province. The εHf values (?.3 to 6.6) of the youngest zircon crystals from the Binchuan volcanic sequence are similar to those (? to 10) of co-magmatic zircon crystals from the intrusive rocks of the Emeishan large igneous province. Our new data confirm that the Binchuan volcanic sequence is an integral part of the Emeishan large igneous province. The disputed and undisputed picrites in Sichuan and Yunnan have similar olivine Fo-Ni-Mn compositions and whole-rock incompatible trace element ratios such as Th/Nb and Ti/Dy. This, together with their spatially close association with the Emeishan flood basalts, indicates that the disputed picrites also belong to the Emeishan large igneous province. The confusing Cenozoic olivine-rich dikes in the region can be distinguished from the picrites of the Emeishan large igneous province by their different olivine Fo-Ni-Mn compositions and whole-rock incompatible trace element ratios such as Th/Nb and Ti/Dy. The results from this study vindicate the use of the previously-disputed picrites as evidences for Permian mantle plume activity in SW China.