Provenance and tectonic evolution of Lower Paleozoic–Upper Mesozoic strata from Sibumasu terrane, Myanmar Fulong Cai a, ⁎, Lin Ding a,e , Wei Yao a,e , Andrew K. Laskowski b , Qiang Xu a,e , Ji'en Zhang c , Kyaing Sein d a Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Beijing 100101, China b Department of Geosciences, University of Arizona, Tucson, AZ, USA c State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China d Myanmar Geosciences Society, Yangon, Myanmar e Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China abstract article info Article history: Received 24 November 2014 Received in revised form 10 March 2015 Accepted 14 March 2015 Available online xxxx Keywords: Myanmar Sibumasu terrane Detrital zircon dating Provenance analysis Paleogeography Collision The provenance of Sibumasu terrane sedimentary rocks and their tectonic relationships with surrounding terranes exposed in Southeast Asia record separation and accretion of Gondwana-derived terranes during Late Paleozoic and Mesozoic time. This paper reports sandstone petrographic and U–Pb detrital zircon geochronologic data from Ordovician to Lower Jurassic strata within the Sibumasu terrane in Shan State, Myanmar. The Ordovi- cian strata are composed of limestone and siltstone. The Lower Silurian Linwe and Upper Silurian Namhism For- mations are comprised of limestone, silty sandstone, conglomerate and sandstone, respectively. Sandstones from both Ordovician and Silurian strata are dominated by 567–470 Ma and 982–917 Ma detrital zircons that are interpreted to be sourced from the eastern Gondwana supercontinent. The Carboniferous unit is composed of metasedimentary rocks (phyllite, slate, quartzite, and meta-marl). Sandstones from Carboniferous units show a strong 1165–1070 Ma detrital zircon age peak that is not present in the Ordovician and Silurian strata. These zircon grains were most likely derived from both the Albany–Fraser Province in Southwest Australia and Maud Province in Antarctic. The Upper Triassic to Lower Jurassic, shallow marine Loi-an Group consists of thin- to medium-bedded sandstone and mudstone that unconformably overly the Permian to Middle Triassic Plateau Limestone Group. Sandstones from the Loi-an Group contain abundant Permian to Triassic detrital zircons that are interpreted to have been derived from the Sukhothai Arc of the western Indochina terrane. Formation of this arc is attributed to eastward (present coordinates) subduction of Paleo-Tethyan oceanic lithosphere beneath Indochina. Therefore, we propose that the Sibumasu terrane was juxtaposed against northwestern Australia as part of the Gondwana supercontinent during Paleozoic to Early Permian time. During the Late Triassic and Early Jurassic, Sibumasu strata record an abrupt influx of Permian and Triassic zircon grains, signifying a change in provenance from Gondwana to the Sukhothai Arc. These data are consistent with a tectonic model involving rifting of the Sibumasu terrane from Gondwana and subsequent docking with the Indochina/Simao terranes dur- ing Mesozoic time. © 2015 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. 1. Introduction The assemblage of continental Southeast Asia is attributed to long- lived terrane dispersion from eastern Gondwana and progressive accre- tion during closure of Late Paleozoic–Paleocene Tethyan oceans and fringing back-arc basins (Hall, 2002; Sone and Metcalfe, 2008; Metcalfe, 2011a,b; Sone et al., 2012; Cawood et al., 2013; Metcalfe, 2013; Xu et al., 2013). Subsequently, mainland Southeast Asia experi- enced deformation, metamorphism and clockwise rotation associated with the India–Asia collision during the Cenozoic (Dewey et al., 1988; Yin and Harrison, 2000; Kornfield et al., 2014). Recently, abundant pa- leogeographic reconstructions and tectonic evolution models of this region have been proposed based on multidisciplinary biogeograph- ic, tectonostratigraphic and paleomagnetic studies (Metcalfe, 1996a, b; Hall, 2002, 2012; Ali et al., 2013; Metcalfe, 2013). As a result, the primary tectonic architecture and accretion history of Southeast Asia are relatively well constrained with a two-phase tectonic model: (1) continental blocks comprising North China, Indochina, Tarim and South China rifted from eastern Gondwana during the De- vonian opening of the Palaeo-Tethys Ocean (Metcalfe, 1996a, 2006); and (2) subsequently, the Sibumasu terrane rifted from eastern Gondwana during Early Permian time and drifted northwards to col- lide with the South China/Indochina superterrane (Metcalfe, 2000; Barber and Crow, 2009). Gondwana Research xxx (2015) xxx–xxx ⁎ Corresponding author at: Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Beijing 100101, China. E-mail address: flcai@itpcas.ac.cn (F. Cai). GR-01425; No of Pages 12 http://dx.doi.org/10.1016/j.gr.2015.03.005 1342-937X/© 2015 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr Please cite this article as: Cai, F., et al., Provenance and tectonic evolution of Lower Paleozoic–Upper Mesozoic strata from Sibumasu terrane, Myanmar, Gondwana Research (2015), http://dx.doi.org/10.1016/j.gr.2015.03.005