Wang wei,etl. EARTH PLANET SC LETT,2016. Paleoproterozoic magmatic and metamorphic events link Yangtze to northwest Laurentia in the Nuna supercontinent

发表时间：2016-10-26点击：次

Paleoproterozoic magmatic and metamorphic events link Yangtze to northwest Laurentia in the Nuna supercontinent

Wei Wang ^a^,^b^{, ,},Peter A. Cawood ^c^,^d,Mei-Fu Zhou ^b,Jun-Hong Zhao ^a

^aState Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China
^bDepartment of Earth Sciences, The University of Hong Kong, Hong Kong Special Administrative Region
^cDepartment of Earth Sciences, University of St Andrews, North Street, St Andrews KY16 9AL, UK
^dCentre for Exploration Targeting, School of Earth Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia

Earth and Planetary Science Letters, Volume 433, 1 January 2016, Pages 269–279

http://doi.org/10.1016/j.epsl.2015.11.005

Abstract

Zircons from granitic gneisses in North Vietnam have magmatic cores dated at 2.28–2.19 Ga, and constitute the first reported evidence of continental crust with these ages in the Yangtze Block of the South China Craton. Overgrowths on zircon rims indicate two periods of metamorphism at 1.97–1.95 Ga and ∼1.83 Ga. These events, along with a previously reported ∼2.36 Ga metamorphic overgrowth on ∼2.9 Ga crystallized zircons from the same region, suggest a sequence of events similar to that recorded for the northwestern region of Laurentia and possibly Siberia, which are associated with assembly of the Nuna supercontinent. These include the 2.4–2.3 Ga Arrowsmith Orogen and a range of events in the interval 2.32–1.80 Ga, including accretionary magmatism in northwestern Laurentia and Siberia (2.32–2.07 Ga), the Thelon orogeny (2.02–1.96 Ga) and the 1.85–1.80 Ga collision between the Superior and Hearne–Rae cratons during the Trans-Hudson Orogen in Laurentia, and the Akitkan Orogen in Siberia (2.03–1.86 Ga). Subsequent attempted breakup of Nuna may be represented by ca. 1.80 to 1.59 Ga consanguineous extension related sedimentation and magmatism in the southwestern Yangtze Block and northwestern Laurentia. These correlations favor location of the Yangtze Block adjacent to northwest Laurentia, and possibly Siberia, within the Nuna supercontinent.