Architecture and composition of ocean floor subducted beneath northern Gondwana during Neoproterozoic to Cambrian: A palinspastic reconstruction based on Ocean Plate Stratigraphy (OPS) |
| |
| Institution: | 1. Czech Geological Survey, Klárov 3, Prague, 118 21, Czech Republic;2. Institute of Geology and Paleontology, Faculty of Science, Charles University, Albertov 6, Prague, 128 43, Czech Republic;3. Institute of Geology, The Czech Academy of Sciences, Rozvojová 269, Prague, 165 00, Czech Republic;4. Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, Prague 128 43, Czech Republic;5. Laboratories of the Geological Institutes, Faculty of Science, Charles University, Albertov 6, Prague, 128 43, Czech Republic;1. Wuhan Center of Geological Survey, China Geological Survey, Wuhan 430205, China;2. State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;3. Department of Earth and Environmental Sciences, University of Windsor, Ontario, Canada;4. State Key Lab of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China;5. Key Laboratory of Marine Hydrocarbon Resources Environmental Geology, Ministry of Natural Resources, Qingdao Institute of Marine Geology, Qingdao 266071, China;6. Key Laboratory of Depositional Mineralization & Sedimentary Minerals, Shandong University of Science and Technology, Qingdao 266590, China;7. School of Earth Sciences, China University of Geosciences Wuhan, Wuhan 430074, China;1. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China;2. College of Geoscience, China University of Petroleum, Beijing, China;3. Key Laboratory of Tectonics and Petroleum Resources of the Ministry of Education, School of Earth Resources, China University of Geosciences, Wuhan, China;4. Energy & Geoscience Institute, University of Utah, Salt Lake City, UT, USA;5. Unconventional Petroleum Research Institute, China University of Petroleum, Beijing, China;6. Centre for Earth Sciences, Indian Institute of Science, Bangalore, India;7. School of Earth Sciences and Resources, China University of Geosciences Beijing, Beijing 100083, China;8. Department of Earth Sciences, University of Adelaide, SA 50005, Australia;9. Earth Dynamics Research Group, TIGeR (The Institute of Geoscience Research), Department of Applied Geology, Curtin University, Perth, Australia;10. Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA;11. Department of Computer Science, University of Idaho, Moscow, ID, 83843, USA;1. Centre for Lithospheric Research, Czech Geological Survey, Prague, Czech Republic;2. Ecole et Observatoire des Sciences de la Terre, Université de Strasbourg, France;3. Institute of Petrology and Structural Geology, Charles University in Prague, Czech Republic;4. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, China;5. Institute of Geological Sciences, Polish Academy of Sciences, Krakow, Poland;6. Department of Earth Science, University of California, Santa Barbara, CA 93106, USA |
| |
| Abstract: | The Blovice accretionary complex, Bohemian Massif, hosts well-preserved basaltic blocks derived from an oceanic plate subducted beneath the northern active margin of Gondwana during late Neoproterozoic to early Cambrian. The major and trace element and Hf–Nd isotope systematics revealed two different suites, tholeiitic and alkaline, whose composition reflects different sources of melts within a back-arc basin setting. The former suite has composition similar to mid-ocean ridge basalts (MORB), yet with striking enrichment in large-ion lithophile elements (LILE) and Pb paralleled by depletion in Nb, in agreement with its derivation from depleted mantle fluxed by subduction-related fluids. In contrast, the latter suite has composition similar to ocean island basalts (OIB) with variable contribution of ancient, recycled crustal material. We argue that both suites represent volcanic members of Ocean Plate Stratigraphy (OPS) and indicate that the oceanic realm consumed by the Cadomian subduction was a complex mosaic of intra-oceanic subduction zones, volcanic island arcs, and back-arc basins with mantle plume impinging the spreading centre. Hence, the basalt geochemistry implies that two distinct domains of oceanic lithosphere may have existed off the Gondwana’s continental edge: an outboard domain, made up of old and less buoyant oceanic lithosphere (remnants of the Mirovoi Ocean surrounding former Rodinia?) that was steeply subducted and generated the back-arcs, and young, hot, and more buoyant oceanic lithosphere generated in the back-arcs and later involved in accretionary complexes as dismembered OPS. Perhaps the best recent analogy of this setting is the Izu Bonin–Mariana arc–Philippine Sea in the western Pacific. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
