New zircon UPb ages of the pre-Sturtian rift successions from the western Yangtze Block , South China and their geological significance

The Neoproterozoic Kaijianqiao Formation is one of the most important pre-Sturtian rift successions in South China and there has long been a lack of reliable geochronological constraints for its minimum depositional age. In this study, new zircon U-Pb ages of volcaniclastic rocks from the topmost Kaijianqiao Formation are presented. The youngest SHRIMP and LA-ICP-MS zircon Pb/U weighted mean ages of the tuff sample are 715.0 ± 9.8 and 718.8 ± 9.4 Ma, respectively. The youngest LA-ICP-MS zircon Pb/U weighted mean age of the tuffaceous siltstone sample is 720.8 ± 7.4 Ma and represents the maximum depositional age of the topmost Kaijianqiao Formation. The results show that the minimum depositional age of the Kaijianqiao Formation in the western Yangtze Block should be ca. 715 Ma, consistent with other pre-Sturtian rift successions in South China, such as the Banxi Group, Chengjiang, and Liantuo formations. Together with the published zircon U-Pb ages, it is demonstrated that the Sturtian glaciation in South China (Jiangkou glaciation) most likely initiated around 715 Ma. In other Rodinia blocks, like Laurentia and Arabia, the Sturtian glaciation probably started between 712 and 717 Ma, thus our new results further support that the Sturtian glaciation was a rapid and globally synchronous event. Other Pb/U zircon ages display five distinct peaks at ca. 751, 780, 799, 819, and 848 Ma, which corresponded to the tectonic-magmatic events related to the break-up of Rodinia. ARTICLE HISTORY Received 29 October 2015 Accepted 10 January 2016

[1]  W. McClelland,et al.  Detrital zircon U-Pb geochronological and Hf isotopic constraints on the geological evolution of North Yukon , 2019, Circum-Arctic Structural Events: Tectonic Evolution of the Arctic Margins and Trans-Arctic Links with Adjacent Orogens.

[2]  Xuan‐Ce Wang,et al.  Mid-Neoproterozoic diabase dykes from Xide in the western Yangtze Block, South China: New evidence for continental rifting related to the breakup of Rodinia supercontinent , 2015 .

[3]  Lei Liu,et al.  Neoproterozoic intraplate crustal accretion on the northern margin of the Yangtze Block: Evidence from geochemistry, zircon SHRIMP U–Pb dating and Hf isotopes from the Fuchashan Complex , 2015 .

[4]  F. Macdonald,et al.  Kikiktat Volcanics of Arctic Alaska—Melting of Harzburgitic Mantle Associated with the Franklin Large Igneous Province , 2015 .

[5]  F. Macdonald,et al.  A Cryogenian chronology: Two long-lasting synchronous Neoproterozoic glaciations , 2015 .

[6]  Zhang Yingli,et al.  LA-ICP-MS zircon U-Pb age and geochemistry of Xiatianba A-type granites in Dongchuan, Northeast Yunnan, and their tectonic significance , 2014 .

[7]  F. Macdonald,et al.  Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth , 2013, Proceedings of the National Academy of Sciences.

[8]  Jian-Hui Liu,et al.  Opening time and filling pattern of the Neoproterozoic Kangdian Rift Basin, western Yangtze Continent, South China , 2013, Science China Earth Sciences.

[9]  Zheng‐Xiang Li,et al.  Neoproterozoic glaciations in a revised global palaeogeography from the breakup of Rodinia to the assembly of Gondwanaland , 2013 .

[10]  Wu Hao,et al.  Discussion on the Bottom of Nanhua System: Evidences from Sedimentology and Isotopic Geochronology , 2013 .

[11]  Xian‐Hua Li,et al.  Episodic Precambrian crust growth: Evidence from U–Pb ages and Hf–O isotopes of zircon in the Nanhua Basin, central South China , 2012 .

[12]  S. Bowring,et al.  A users guide to Neoproterozoic geochronology , 2011 .

[13]  Lianjun Feng,et al.  Chapter 32 Neoproterozoic glacial records in the Yangtze Region, China , 2011 .

[14]  L. Yongsheng,et al.  Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS , 2010 .

[15]  Yue-heng Yang,et al.  Detrital zircon U-Pb geochronological and Lu-Hf isotopic constraints on the Precambrian magmatic and crustal evolution of the western Yangtze Block, SW China , 2009 .

[16]  P. Hoffman,et al.  A palaeogeographic context for Neoproterozoic glaciation , 2009 .

[17]  Xian‐Hua Li,et al.  Variable involvements of mantle plumes in the genesis of mid-Neoproterozoic basaltic rocks in South China: A review , 2009 .

[18]  Dunyi Liu,et al.  SHRIMP zircon U-Pb age constraints on Neoproterozoic Quruqtagh diamictites in NW China , 2009 .

[19]  Mei-Fu Zhou,et al.  Association of Neoproterozoic A- and I-type granites in South China: Implications for generation of A-type granites in a subduction-related environment , 2008 .

[20]  F. Corfu,et al.  Zircon M257 ‐ a Homogeneous Natural Reference Material for the Ion Microprobe U‐Pb Analysis of Zircon , 2008 .

[21]  P. Allen,et al.  Geochronologic constraints on the chronostratigraphic framework of the Neoproterozoic Huqf Supergroup, Sultanate of Oman , 2007, American Journal of Science.

[22]  Jin Wei.  SHRIMP dating of adakites in western Qinling and their implications. , 2005 .

[23]  W. Jian.  New advances in the study of “the Nanhuaan System”-with particular reference to the stratigraphic division and correlation of the Nanhuaan System, South China , 2005 .

[24]  S. Xiao,et al.  New constraints on the ages of Neoproterozoic glaciations in south China , 2004 .

[25]  R. Korsch,et al.  TEMORA 1: a new zircon standard for Phanerozoic U–Pb geochronology , 2003 .

[26]  Ó. Ingólfsson,et al.  Massive ground ice body of glacial origin at Yugorski Peninsula, arctic Russia , 2003 .

[27]  Jian Wang,et al.  History of Neoproterozoic rift basins in South China: implications for Rodinia break-up , 2003 .

[28]  Zheng‐Xiang Li.  Geochronology of Neoproterozoic syn-rift magmatism in the Yangtze Craton, South China and correlations with other continents: evidence for a mantle superplume that broke up Rodinia , 2003 .

[29]  Dunyi Liu,et al.  Lower boundary age of the Nanhua System and the Gucheng glacial stage: Evidence from SHRIMP II dating , 2003 .

[30]  K. Ludwig.  User's Manual for Isoplot 3.00 - A Geochronological Toolkit for Microsoft Excel , 2003 .

[31]  Mei-Fu Zhou,et al.  SHRIMP U-Pb zircon geochronological and geochemical evidence for Neoproterozoic arc-magmatism along the western margin of the Yangtze Block, South China. , 2002 .

[32]  Y. Liu,et al.  U-Pb zircon geochronology, geochemistry and Nd isotopic study of Neoproterozoic bimodal volcanic rocks in the Kangdian Rift of South China : Implications for the initial rifting of Rodinia , 2002 .

[33]  P. Allen,et al.  New U-Pb zircon dates for the Neoproterozoic Ghubrah glaciation and for the top of the Huqf Supergroup, Oman , 2000 .

[34]  W. Compston,et al.  U‐Pb geochronology of zircons from lunar breccia 73217 using a sensitive high mass‐resolution ion microprobe , 1984 .

[35]  R. Steiger,et al.  Subcommission on geochronology: Convention on the use of decay constants in geo- and cosmochronology , 1977 .

[36]  J. Kramers,et al.  Approximation of terrestrial lead isotope evolution by a two-stage model , 1975 .