caa a22 4500 606149112 CHVBK 20210128100532.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00531-014-1056-z doi (NATIONALLICENCE)springer-10.1007/s00531-014-1056-z Geochemistry and zircon ages of mafic dikes in the South Qinling, central China: evidence for late Neoproterozoic continental rifting in the northern Yangtze block [Elektronische Daten] [Xiyan Zhu, Fukun Chen, Bingxiang Liu, He Zhang, Mingguo Zhai] Neoproterozoic volcanic-sedimentary sequences of the southern Qinling belt, central China, were intruded by voluminous mafic dikes. secondary ion mass spectrometry zircon U-Pb dating indicates that these dikes were emplaced at 650.8±5.2Ma, coeval with mafic rocks occurring at the northern margin of the Yangtze block. The dikes are characterized by enrichment of large ion lithophile elements, high Ti contents (up to 3.73wt%) and Nb/Ta ratios between 14.5 and 19.6, suggesting a mantle source of oceanic island basalt affinity. Initial 87Sr/86Sr ratios show positive correlation with SiO2 contents and negative correlation with Zr/Nb ratios, implying that these rocks were affected by crustal contamination during the magma ascend and emplacement process. The dikes have initial ε Nd values of +0.2 to +3.3, low 206Pb/204Pb ratios of 16.96-17.45, and moderate 87Sr/86Sr ratios of 0.7043-0.7076, likely pointing to the involvement of an enriched mantle source. The mafic dikes and coeval mafic volcanic equivalents in the South Qinling and the northern Yangtze are hypothesized to be related with the prolonged breakup of the supercontinent Rodinia, suggesting that continental rifting lasted until ca. 650Ma. Springer-Verlag Berlin Heidelberg, 2014 South Qinling nationallicence Neoproterozoic nationallicence Mafic dike nationallicence Geochemistry nationallicence Zircon age nationallicence Zhu Xiyan Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut Chen Fukun Key Laboratory of Crust-Mantle Materials and Environments, School of Earth Sciences, University of Science and Technology of China, 230026, Hefei, China aut Liu Bingxiang Key Laboratory of Crust-Mantle Materials and Environments, School of Earth Sciences, University of Science and Technology of China, 230026, Hefei, China aut Zhang He Key Laboratory of Crust-Mantle Materials and Environments, School of Earth Sciences, University of Science and Technology of China, 230026, Hefei, China aut Zhai Mingguo Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/1(2015-01-01), 27-44 1437-3254 104:1<27 2015 104 531 https://doi.org/10.1007/s00531-014-1056-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-014-1056-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhu Xiyan Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut NATIONALLICENCE 700 1- Chen Fukun Key Laboratory of Crust-Mantle Materials and Environments, School of Earth Sciences, University of Science and Technology of China, 230026, Hefei, China aut NATIONALLICENCE 700 1- Liu Bingxiang Key Laboratory of Crust-Mantle Materials and Environments, School of Earth Sciences, University of Science and Technology of China, 230026, Hefei, China aut NATIONALLICENCE 700 1- Zhang He Key Laboratory of Crust-Mantle Materials and Environments, School of Earth Sciences, University of Science and Technology of China, 230026, Hefei, China aut NATIONALLICENCE 700 1- Zhai Mingguo Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/1(2015-01-01), 27-44 1437-3254 104:1<27 2015 104 531