Accepted Manuscript Detrital zircon dating and tracing the provenance of dinosaur bone beds from the Late Cretaceous Wangshi Group in Zhucheng, Shandong, East China Wei An, Hong-Wei Kuang, Yong-Qing Liu, Nan Peng, Ke-Ming Xu, Huan Xu, Peng Zhang, Ke-Bai Wang, Shu-Qing Chen, Yan-Xia Zhang PII: S2095-3836(15)30054-7 DOI: 10.1016/j.jop.2015.11.002 Reference: JOP 17 To appear in: Journal of Palaeogeography Received Date: 26 August 2015 Accepted Date: 17 November 2015 Please cite this article as: An, W., Kuang, H.-W., Liu, Y.-Q., Peng, N., Xu, K.-M., Xu, H., Zhang, P., Wang, K.-B., Chen, S.-Q., Zhang, Y.-X., Detrital zircon dating and tracing the provenance of dinosaur bone beds from the Late Cretaceous Wangshi Group in Zhucheng, Shandong, East China, Journal of Palaeogeography (2015), doi: 10.1016/j.jop.2015.11.002. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. 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Journal of Palaeogeography, (2016), 5, (1), 400 −000 (00092) doi: ACCEPTED MANUSCRIPT 1 Biopalaeogeography and palaeoecology 2 Detrital zircon dating and tracing the provenance of dinosaur 3 bone beds from the Late Cretaceous Wangshi Group in 4 Zhucheng, Shandong, East China 5 ∗ ∗ 6 Wei An a, Hong-Wei Kuang a, , Yong-Qing Liu a, , Nan Peng a, Ke-Ming Xu b, 7 Huan Xu a, Peng Zhang c, Ke-Bai Wang d, Shu-Qing Chen d, Yan-Xia Zhang d 8 a Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China 9 b Shandong Institute of Geology Survey, Jinan 250000, Shandong, China 10 c School of Earth Sciences and Resources, China University of Geosciences (Beijing), 11 Beijing 100083, China 12 d Dinosaur Research Center of Zhucheng, Zhucheng 262200, Shandong, China 13 14 Received 26 August 2015; accepted 29 October 2015 15 Available online MANUSCRIPT 16 17 Abstract The mass burial of dinosaur bone fossils in the Late 18 Cretaceous Wangshi Group in Zhucheng, Shandong Province has been a 19 research focus in recent years. However, the provenance of the dinosaur bone 20 fossils and the accurate depositional age of the bone beds remain ambiguous. 21 Through U −Pb dating of detrital zircons collected from six conglomerate 22 samples from dinosaur bone beds, we found that the youngest single grain age 23 (YSG) of sample 090414-24-D was 77.3 Ma, representing the maximum 24 depositional age of the dinosaur fossil beds and sediments. This also indicates 25 that the HongtuyaACCEPTED Formation was deposited during the Campanian. The age 26 range had an interval of 130~100 Ma. Dating results revealed an age peak of 27 120~110 Ma, which corresponds with the peak age of volcanic rocks of the ∗ Corresponding author. E-mail address: [email protected] (Kuang); [email protected] (Liu). Peer review under responsibility of China University of Petroleum (Beijing). 1 / 31 ACCEPTED MANUSCRIPT 28 Lower Cretaceous Qingshan Group. The volcanic rocks of the Qingshan 29 Group are mainly exposed in Laiyang, to the north of Zhucheng, although a 30 few also appear to the south and northwest. Through analysis of conglomerate 31 composition and palaeocurrents in the sediments containing the bone beds, 32 we found that the gravel composition of three groups of the conglomerate was 33 volcanic or pyroclastic rock. Three groups of palaeocurrents suggested that 34 the main sediment source of the Wangshi Group dinosaur bone beds was from 35 the north −northwest of the Basin. Only one group had a provenance south of 36 the basin. This study revealed that the areas of Laiyang and the Yishu Fault 37 Zone were the main provenance areas of both dinosaur bone fossils and 38 sediments of the Wangshi Group in Zhucheng. The southern margin of the 39 Zhucheng Basin may be a secondary source area. This research provides an 40 important basis for judging the deposition time and sediment source of fossil 41 layers in the Wangshi Group, as well as reconstructing the palaeogeography of 42 the Wangshi Group in the Jiaolai Basin. 43 KEYWORDS dinosaur bone beds, provenance, detrital zircon, 44 geochronology, Wangshi Group, Shandong Zhucheng 45 MANUSCRIPT 46 1 Introduction 47 Massive dinosaur bone and egg fossils have been found in Late Cretaceous strata, but 48 previous research has concentrated mainly on the taxonomy and taphonomy of the dinosaur fossils. 49 Few studies have focused on determining the accurate depositional age of the dinosaur bone beds. 50 East Shandong is one of the most developed regions of Cretaceous strata. Not only were dinosaur 51 tracks found in the Lower Cretaceous Laiyang and Qingshan Groups(Li et al ., 2005, 2008, 2011, 52 2015; Xing et al ., 2010, 2012; Xu et al ., 2013; Kuang et al ., 2013a), but dinosaur bone and egg 53 fossils were foundACCEPTED in the Upper Cretaceous Wangshi Group (Yang, 1954; Hu, 1973; Hu et al ., 54 2001; Zhao et al ., 2007; Liu et al ., 2010; Xu et al ., 2010; Hone et al ., 2011; Kuang et al ., 2013b, 55 2014). The Wangshi Group was mainly composed of alluvial fan facies. Abundant dinosaur bones 56 were buried in debris flow sediments. 57 Many researches involved dinosaur palaeontology, taxonomy (Yang, 1954; Hu, 1973; Hu 2 / 31 ACCEPTED MANUSCRIPT 58 et al ., 2001; Zhao et al ., 2007; Ji, 2010; Xu et al ., 2010; Hone et al ., 2011), taphonomy (Liu et al ., 59 2009, 2010, 2011; He et al ., 2012; Kuang et al ., 2013b, 2014), etc ., have been carried out on the 60 dinosaur fossils in the Zhucheng Basin, and important progress has been made. New 61 potassium −argon (K −Ar) and Ar −Ar geochronology results have also been obtained for the upper 62 portion of the strata containing dinosaur fossils. Meng et al . (2006) used a whole-rock K −Ar 63 method to determine the age of the Hongtuya Formation, and found that the age of the Zhucheng 64 basalt is 76.2±1.6 Ma. Yan et al . (2003) found, from the basalt 40 Ar −39 Ar geochronology, that the 65 Daxizhuang basalt of the Upper Hongtuya Group was aged at 73.5±0.3 Ma (Yan et al ., 2003; 66 Meng et al ., 2006). Basalt samples were collected from the top of the Hongtuya Formation in the 67 Wangshi Group, but dinosaur fossils were mainly buried in the bottom of this formation in the 68 Zhucheng Basin. Thus, it is still not clear whether or not the basalt ages (76–73 Ma) are consistent 69 with the time of the bone burial. Previous studies have described the dinosaur fossils as 70 allochthonous deposits (He et al ., 2012; Kuang et al ., 2014). But where did the dinosaur bone 71 fossils and their host sediment come from? Previous work based on the preferred orientation of 72 dinosaur bones and conglomerate suggested that the sediment provenances were either south or 73 north uplifts of the Jiaolai Basin (He et al ., 2012; KuangMANUSCRIPT et al ., 2014). However, further systematic 74 geological evidence is needed. 75 So far, nearly 8000 dinosaur fossils have been discovered in Kugou, Longgujian, Xijiantun 76 and Zangjiazhuang, to the southwest of Zhucheng City. More than 3000 dinosaur fossils with 77 different sizes and random arrangement were buried in Kugou Section, which are only about 300 78 meters’ long. The abundance of Late Cretaceous dinosaur fossils in the Zhucheng area is a global 79 rarity. The buried dinosaur groups can be analogized with those buried in other parts of Asia and 80 North America during the Late Cretaceous (Kuang et al ., 2014). The importance and scientific 81 significance of the dinosaur fossils of the Wangshi Group in the Zhucheng Basin are self-evident. 82 Although previousACCEPTED studies on the palaeontology, taxonomy, taphonomy, etc. , have made 83 substantial progress (Hu, 1973; Hu et al ., 2001; Zhao et al ., 2007; Liu et al ., 2010; Kuang et al ., 84 2014), there is still a lack of sufficient data to constrain the burial age of the fossil layer. 85 Detrital zircon geochronology has been used to constrain the depositional age of host 86 sediment and reconstruct provenance (Nelson et al ., 2001; Dickinson and Gehrels, 2009; Jones et 87 al ., 2009; Gehrels, 2011, 2014; Xie et al ., 2012; Tucker et al ., 2013; Fang et al ., 2015). This is an 3 / 31 ACCEPTED MANUSCRIPT 88 important and effective means of basin analysis, especially the study of provenance. This paper, 89 based on dating data of detrital zircons collected from six conglomerate samples from dinosaur 90 bone beds in the Zhucheng Basin, combined with gravel composition and palaeocurrent data, aims 91 to constrain the age of deposition of the dinosaur fossil layers and judge the provenance of the 92 Wangshi Group. The findings may also provide essential data about the Cretaceous 93 palaeogeographic evolution and dinosaur taphonomy in the Jiaolai Basin. 94 95 2 Geological Setting 96 Shangdong Province is located in the eastern part of the North China Craton (NCC). The 97 Tancheng −Lujiang (Tan −Lu) Fault Zone, called the Yishu Fault Zone in Shandong, separates the 98 region into East and West Shandong. The Jiaolai Basin is located in the East Shandong area in the 99 eastern part of the North China Craton. It is a late Mesozoic extensional faulted basin (Dai et al ., 100 1995; Shi et al ., 2003; Zhang et al ., 2008).