Petrogenesis and tectonic implications of the Neoarchean North Liaoning tonalitic-trondhjemitic gneisses of the North China Craton, North China

• Published in: Journal of Asian Earth Sciences
• Main Authors: Wang, Maojiang, Liu, Shuwen, Wang, Wei, Wang, Kang, Yan, Ming, Guo, Boran, Bai, Xiang, Guo, Rongrong
• Other Authors: Liu, SW (reprint author), Peking Univ, Key Lab Orogen Belts & Crustal Evolut, Minist Educ, Beijing 100871, Peoples R China., Peking Univ, Key Lab Orogen Belts & Crustal Evolut, Minist Educ, Beijing 100871, Peoples R China., China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Sch Earth Sci & Resources, Beijing 100083, PR, Peoples R China., PetroChina Liaohe Oilfield 10 Co, Res Inst Petr Explorat & Dev, Panjin 124000, Peoples R China., China Earthquake Adm, Inst Geol, Key Lab Act Tecton & Volcano, Beijing 100029, Peoples R China., Northeastern Univ, Sch Resources & Civil Engn, Shenyang 110819, Peoples R China.
• Format: Journal/Newspaper
• Language: English
• Published: JOURNAL OF ASIAN EARTH SCIENCES 2016
• Subjects: Tonalitic-trondhjemitic gneisses; Zircon U-Pb and Lu-Hf isotopic systematics; Partial melting of the subducted slab and juvenile crusts; An active continental margin; Tangtu-Majuanzi area of the NCC; ZIRCON U-PB; LU-HF ISOTOPES; EARLY CONTINENTAL-CRUST; CENTRAL OROGENIC BELT; ISUA GREENSTONE-BELT; COLLECTOR ICP-MS; EASTERN HEBEI; WEST GREENLAND; CENTRAL ZONE; FRACTIONAL CRYSTALLIZATION; Greenland
• Online Access: https://hdl.handle.net/20.500.11897/458255; https://doi.org/10.1016/j.jseaes.2016.09.012

Tonalitic-trondhjemitic-granodioritic (TTG) gneisses are dominant lithological assemblages in Archean high grade metamorphic terranes in the world. These TTG gneisses preserve important information in formation and evolution of Archean continental crust. Tangtu-Majuanzi microblock in North Liaoning Province (NLP) is one of the major Neoarchean metamorphic basement terranes in the northeastern margin of the North China Craton (NCC). The Tangtu-Majuanzi microblock is composed mainly of Neoarchean tonalitic-trondhjemitic (TT) gneisses, subordinate granodioritic to monzogranitic association (GMA) and minor supracrustal rocks. The tonalitic-trondhjemitic gneisses are divided into high MgO Group (HMG) and low MgO Group (LMG) based on their chemical compositions. Detailed petrogenetic investigations suggest that the magmatic precursors of the HMG samples were derived from partial melting of subducted slabs and contaminated by the overlying mantle wedge during its ascent; whereas, magmatic precursors of the LMG samples were derived from the juvenile lower crust. LA-ICPMS zircon U-Pb isotopic dating analyses reveal that the magmatic precursors of the HMG samples were formed at 2553-2531 Ma. An older HMG tonalitic gneiss sample was discovered at Sandaoguan in the southmost of the studied area, with its magmatic precursor emplaced at 2680 Ma. The magmatic precursors of the LMG samples emplaced at 2595-2583 Ma. Combined with previous credible chronological data, our newly obtained zircon U-Pb dating and Lu-Hf isotopic data indicate that three episodes of magmatism at 2700-2680 Ma, similar to 2600-2570 Ma and similar to 2550-2510 Ma occurred in the Tangtu-Majuanzi microblock, and the TT gneisses in this microblock were subjected to generally amphibolite-facies metamorphisrri at similar to 2520-2470 Ma. Based on the above Neoarchean crust-mantle thermal-dynamic processes, we propose that the Neoarchean magmatism and metamorphism in the Tangtu-Majuanzi microblock of North Liaoning Province occurred in an active continental margin. (C) 2016 Elsevier Ltd. All rights reserved. National Nature Science Foundation of China [41272209, 41472165, 41530207, 41502179] SCI(E) ARTICLE [e-mail] 12-39 131