1 3 Int J Earth Sci (Geol Rundsch) DOI 10.1007/s00531-016-1314-3 ORIGINAL PAPER Detrital zircon provenance analysis in the Zagros Orogen, SW Iran: implications for the amalgamation history of the Neo-Tethys Zhiyong Zhang 1,2 · Wenjiao Xiao 1,3 · Mahmoud Reza Majidifard 4 · Rixiang Zhu 1 · Bo Wan 1,3 · Songjian Ao 1 · Ling Chen 1,3 · Mahnaz Rezaeian 5 · Rasoul Esmaeili 1 Received: 29 October 2015 / Accepted: 24 February 2016 © Springer-Verlag Berlin Heidelberg 2016 several workers, suggests that the sequence studied lay on the Arabia passive margin and that initial collision occurred prior to 18 Ma; Hypothesis B, modified from the Makran model, which is here preferred, suggests that Paleogene to Upper Miocene sediments were sourced from the northern Neo-Tethyan accretionary complex or Eurasia, and carry no input from Arabia, whereas the Lower Pliocene sample shows a mixed provenance from both Arabia and Eurasia, suggesting that collision occurred between ~11.2 and 5 Ma. Keywords Neo-Tethys · Zagros Orogen · Arabia–Eurasia collision · Detrital zircon U–Pb geochronology · Hf isotopes Introduction The NW–SE trending Zagros Orogen resulted from the col- lision between Arabia and Eurasia (Fig. 1). It consists of three different parallel structural units, which from NE to SW are: (1) the Urumieh–Dokhtar magmatic arc (UDMA); (2) the metamorphic and magmatic Sanandaj–Sirjan zone (SSZ); and (3) the Zagros fold and thrust belt (ZFTB). The so-called Main Zagros Thrust (MZT) is widely considered to represent the suture between the Arabian and Eurasian plates (Agard et al. 2011; Alavi 1994). The SSZ is gener- ally regarded to be located on the southern active margin of the Eurasian plate, which was thrust southwestward over the ZFTB (Homke et al. 2009). The ZFTB is characterized by well-developed open folds, which involve the entire 12–14 km-thick sedimentary cover of the Zagros Basin. The Zagros Orogen is separated from the Makran region by the Oman Line (Mouthereau et al. 2012; Tale- bian and Jackson 2004). New field observations and geo- chemical and geochronological data indicate affiliation Abstract The Zagros Orogen developed as a result of Arabia–Eurasia collision. New in situ detrital zircon U– Pb and Hf isotopic analyses from a Cenozoic sedimentary sequence in SW Iran are used to unravel the amalgamation history of Neo-Tethys. Data indicate that: (1) Paleocene and Eocene strata (58 and 45 Ma, respectively) were sourced from obducted ophiolite and Triassic volcanics, (2) Lower Miocene (~18 Ma) strata indicate mixed provenance from obducted ophiolite and Iranian magmatic rocks, (3) Mid to Upper Miocene sediments (~14 to 11.2 Ma) were mainly sourced from Sanandaj–Sirjan zone granitoids to the north, and (4) Lower Pliocene (~5 Ma) sediments mainly show Arabian age characteristics, with a minor Eurasian affin- ity component. Two hypotheses are outlined to highlight the key events: Hypothesis A, previously published by Electronic supplementary material The online version of this article (doi:10.1007/s00531-016-1314-3) contains supplementary material, which is available to authorized users. * Zhiyong Zhang zyzhang@mail.iggcas.ac.cn * Wenjiao Xiao wj-xiao@mail.iggcas.ac.cn 1 State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2 School of Earth Sciences, The University of Melbourne, Parkville, VIC 3010, Australia 3 CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China 4 Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran 5 Institute for Advanced Studies in Basic Sciences, Zanjan, Iran