Early Neoproterozoic tectonic evolution of the Erguna Terrane (NE China) and its paleogeographic location in Rodinia supercontinent: Insights from magmatic and sedimentary record |
| |
| Institution: | 1. College of Earth Sciences, Jilin University, Changchun 130061, China;2. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China;1. Beijing SHRIMP Centre, Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, China;2. Institute of Geosciences, University of Mainz, 55099 Mainz, Germany;3. Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences, Makarova embankment 2, St. Petersburg, 199034, Russia;4. Geological Institute, Russian Academy of Sciences, Pyzhevskiy pereulok 7, Moscow, 119017, Russia;5. Institute of Earth Sciences, Academia Sinica, P.O. Box 1-55, Taipei 11529, Taiwan;6. Department of Geosciences, National Taiwan University, Taipei 106, Taiwan;7. Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;1. Institute of Geology and Nature Management, Far Eastern Branch of the Russian Academy of Sciences, Blagoveshchensk, Russia;2. College of Earth Sciences, Jilin University, Changchun, China;3. Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences, St. Petersburg, Russia;4. V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia |
| |
| Abstract: | Owing to the lack of early Neoproterozoic geological and geochronological data, most Rodinia supercontinent reconstruction models do not include the Amuria Block in the Central Asian Orogenic Belt (CAOB), and the Amuria Block was varying attributed to the North China, Siberian or Tarim tectonic affinities. In this study, we identified one early Neoproterozoic granitic pluton (964–947 Ma) and one early Neoproterozoic sedimentary unit (<906 Ma) in the Erguna Terrane. The samples (964–947 Ma) are I-type granitoids, and show high zircon in-situ εHf(t) (?2.1–10.0) and whole-rock εHf(t) (1.4–4.8) and high εNd(t) (?2.3 to ?0.8). These granitoids are characterized by high Zr saturation temperature (TZr) (701–835 °C) and no inherited zircons, suggesting high-degree of partial melting of their source rocks. The granites were likely formed by biotite-/muscovite dehydration melting of subalkaline mafic lower crust in a continental arc setting. Detrital zircons of the sandstone sample define an age peak at 923–906 Ma. Early Neoproterozoic age data compilation from the four Amuria microcontinents (i.e., Erguna, Xing'an, Songnen and Jiamusi terranes) in NE China indicate the presence of two major magmatic flare-ups at 964–880 Ma and 850–740 Ma. Considering that early Neoproterozoic magmatic rocks are absent in the Siberian and North China cratons but widespread in the Tarim Craton, we suggested that the Erguna Terrane was part of the Tarim Craton in the Early Neoproterozoic. The Erguna Terrane may have undergone a two-staged Neoproterozoic tectonic evolutionary history: (1) early Neoproterozoic arc accretion in response to the Rodinia assembly, and (2) middle Neoproterozoic break-away from the SW Tarim Craton associated with the Rodinia breakup. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
