Provenance of the early to mid-Paleozoic sediments in the northern Alxa area: Implications for tectonic evolution of the southwestern Central Asian Orogenic Belt |
| |
| Affiliation: | 1. Institute for Peat and Mire Research, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China;2. The Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing 100871, China;3. Research School of Earth Sciences, Australian National University, Mills Road, Canberra, ACT 0200, Australia;1. Department of Geosciences, Biogeology, University of Tübingen, Hölderlinstrasse 12, 72074 Tübingen, Germany;2. Senckenberg Research Centre for Human Evolution and Paleoenvironment, University of Tübingen, Hölderlinstrasse 12, 72076 Tübingen, Germany;3. Instituto de Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano (INCUAPA-CONICET), Universidad Nacional del Centro de la provincia de Buenos Aires, Del Valle 5737, B7400JWI Olavarría, Buenos Aires, Argentina;4. Museo Municipal de Ciencias Naturales Pachamama, Santa Clara del Mar, Argentina;5. Universidad Nacional de Mar del Plata, Argentina;6. Div. Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque, 1900 La Plata, Argentina;7. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR), Provincia de La Rioja, UNLaR, SEGEMAR, UNCa, CONICET, Entre Ríos y Mendoza s/n, 5301 Anillaco, La Rioja, Argentina;1. Institute of Earth Sciences, St-Petersburg State University, University Embankment 7/9, St-Petersburg, 199034, Russia;2. Geological Institute (GIN), Russian Academy of Sciences, Pyzhevskiy 7, Moscow 119017, Russia;3. New South Wales Institute of Frontiers Geoscience, University of Newcastle, Newcastle, NSW 2308, Australia;4. Department of Earth and Atmospheric Sciences, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta T6G 2R3, Canada;1. Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;2. Department of Geology, Northwest University, Xi''an 710069, China;3. Department of Geology and Planetary Science, University of Pittsburgh, 4107 O''Hara Street, Pittsburgh, PA 15260-3332, USA;4. Institute of Earth Sciences, Academia Sinica, Taipei 11529, Taiwan;1. School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China;2. Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China;3. Key Laboratory of Paleomagnetism and Tectonic Reconstruction, Ministry of Land and Resource, Beijing 100081, China;4. Institute of Geomechanics , Chinese Academy of Geological Sciences, Beijing, 100081, China;1. MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China;2. State Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;3. Tianjin Institute of Geology and Mineral Resources, China Geological Survey, Tianjin 300170, China;4. School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China |
| |
| Abstract: | The continental fragments in Northwest China are key to revealing the tectonic and crustal evolution of the Central Asian Orogenic Belt (CAOB). However, their tectonic correlation, affinity and implications have not been well defined. The early to mid-Paleozoic sediments in the northern Alxa area can help to understand this question. These sediments were deposited in a deep to shallow marine environment during a regression. The southeast paleocurrent attributes their provenance to the northwest. Detrital zircons from the collected sandstones record peak ages of approximately 1726 Ma, 1462 Ma, 915 Ma and 438 Ma. The zircon εHf(t) values are negative to positive at 1726 Ma, 915 Ma and 438 Ma, but only positive at 1462 Ma. The detrital zircon U–Pb ages and Hf isotopes suggest the provenance to be the blocks in Central Tianshan and Southern Beishan or their analogs, rather than the Tarim Craton. The source blocks show no tectonic affinity to the Tarim Craton but might be accreted to it in the Neoproterozoic Rodinia. The provenance analyses show tectonic correlation among the northern Alxa, Tianshan and Beishan orogenic belts. The Late Devonian molasse deposits, geochemical shifting to continental margins and suddenly increased early Paleozoic zircons indicate an arc-continent collision. The discovery of more indicators for continental fragments advocates a multiterrane model and dominant crustal reworking/contamination for the tectonocrustal evolution of the CAOB at least during the early to mid-Paleozoic. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
