Ca. 820–640 Ma SIMS U-Pb age signal in the peripheral Vijayan Complex, Sri Lanka: Identifying magmatic pulses in the assembly of Gondwana Samuel Wai-Pan Ng a,⇑ , Martin J. Whitehouse b , Tammy Pui-Yuk Tam a,c , Pathmakumara Jayasingha d , Jean Ping-Mei Wong a , Steven W. Denyszyn e , Joyce Sum-Yee Yiu a , Su-Chin Chang a a Department of Earth Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong b Swedish Museum of Natural History, and Nordic Center for Earth Evolution, Box 50007, SE-104 05 Stockholm, Sweden c Earth System Science Programme, Faculty of Science, The Chinese University of Hong Kong, Sha Tin, New Territories, Hong Kong d National Building Research Organization, 99/1, Jawatta Road, Colombo 05, Sri Lanka e School of Earth and Environment and Centre for Exploration Targeting, University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia article info Article history: Received 13 October 2016 Revised 8 March 2017 Accepted 11 March 2017 Available online 15 March 2017 Keywords: Sri Lanka Vijayan Complex Cryogenian Lurio foreland East Antarctica Gondwana assembly abstract Sri Lanka comprises three roughly north-south trending amphibolite- to granulite-facies lithotectonic complexes, from west to east the Highland Complex, the Wanni Complex, and the Vijayan Complex. These terranes were correlated with other East Gondwana continental terranes with similar lithologies forming at similar ages. The Wanni Complex and the Vijayan Complex have been interpreted as volcanic arc terranes brought together by a double-sided subduction. The Highland Complex represents the meta- morphosed accretionary prism within the suture when the Wanni and Vijayan Complexes were juxtapos- ing against each other. In contrast to the Wanni and Highland Complexes, the Vijayan Complex has yielded only a few geochronological data with satisfactory precision. Previous studies suggested that the Vijayan Complex comprises 1100–924 Ma granitic gneisses, which were metamorphosed during 590–456 Ma. More recently, 772–617 Ma mafic intrusions have been identified. This study divides the Vijayan granitic gneisses and the associated melt products geochemically into a low-Nb series and a more primitive high-Nb series. Our SIMS U-Pb zircon data suggested that both series have protolith magmatic ages of 1062–935 Ma, and metamorphic ages of 580–521 Ma, which is consistent with pre- vious work. However, some of the Vijayan granitic gneisses and granitic anatectic melt products at the Highland-Vijayan tectonic mixed zone preserve an additional Tonian-Cryogenian (820–630 Ma) age signal. This age signal suggested that felsic magmatism also occurred when mafic granulites were emplaced along the Highland-Vijayan boundary, which is broadly coeval with to the bimodal magmatism occurring along the Highland-Wanni boundary. This study also suggests that charnockitisation in the Vijayan Complex occurred at 562 ± 6 Ma during the Neoproterozoic regional metamorphism. The Tonian-Cryogenian signal preserved in the Highland-Vijayan tectonic mixed zone can also be found in the alkaline intrusion hosted by the Namuno Terrane and the Lurio Belt in Mozambique. This indicates a relationship between the Vijayan granitic gneisses and the Lurio foreland metagranitic basement, while the Namuno Terrane and the Lurio Belt are correlated with the Highland-Vijayan tectonic mixed zone. The ages and the isotope signatures of these granitic bodies further suggest a genetic relationship of these granitic bodies with various magmatic intrusions in East Antarctica. Ó 2017 Elsevier B.V. All rights reserved. 1. Introduction The tectonics and palaeogeographical location of Sri Lanka before the assembly of Gondwana remain controversial in recon- structions of late Precambrian geology. The island of Sri Lanka comprises three lithotectonic terranes, from west to east the Wanni Complex, the Highland Complex, and the Vijayan Complex (Figs. 1 and 2). They have similar metamorphic grade and structure to now removed terranes of southern India and eastern Antarctica, but the correlation between these regions has been based upon comparing the age spectra of the basement rocks and associated intrusive rocks (Baur et al., 1991; Hölzl et al., 1991, 1994; Black et al., 1992; Kröner and Williams, 1993; Kröner et al., 1994, 2003, 2013; Shiraishi et al., 1994; Paquette et al., 1994; Collins et al., 2007; Clark et al., 2009a,b; Sajeev et al., 2010; Brandt et al., http://dx.doi.org/10.1016/j.precamres.2017.03.013 0301-9268/Ó 2017 Elsevier B.V. All rights reserved. ⇑ Corresponding author. E-mail address: waipanng@hku.hk (S.W.-P. Ng). Precambrian Research 294 (2017) 244–256 Contents lists available at ScienceDirect Precambrian Research journal homepage: www.elsevier.com/locate/precamres