1 Cretaceous provenance change in the Hegang Basin and its 2 3 connection with the Songliao Basin, NE China: evidence for 4 lithospheric extension driven by palaeo-Pacific roll-back 5 6 1,2,3 1 1 2 7 MINGDAO SUN , HANLIN CHEN *, FENGQI ZHANG , SIMON A. WILDE , 8 A MINNA1, XIUBIN LIN1 & SHUFENG YANG1 9 1 10 Department of Earth Science, Zhejiang University, Hangzhou, Zhejiang 310027, China 11 2Department of Applied Geology, Curtin University, Perth, WA 6845, Australia 12 3 13 Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 14 Guangzhou 510640, China 15 16 *Corresponding author (e-mail: [email protected]) 17 18 19 Abstract: The Cretaceous Hegang Basin is located on the Jiamusi Block, NE China, and separated 20 from the Songliao Basin by the Lesser Xing’an Range (LXR). Seismic interpretation shows that the Chengzihe, Muling and Dongshan formations of the Hegang Basin thicken eastwards with west- 21 wards onlap, indicating that the LXR existed as a palaeo-uplift during that period, whereas the 22 Houshigou Formation shows no thickness change, indicating that the LXR was possibly under 23 water at this time. This is supported by results of detrital zircon analysis from the Hegang Basin 24 in which the Chengzihe Formation is dominated by approximately 180 Ma zircons, which can 25 only be provided by the LXR, whereas the Houshigou Formation records no early Jurassic ages. 26 This view is consistent with previous studies of the Songliao Basin for a provenance change 27 between the Denglouku and Quantou formations. We conclude that the LXR was a highland 28 during deposition of the Chengzihe, Muling and Dongshan formations but that it was under 29 water when the Houshigou Formation was deposited. There was thus a connection between the Hegang and Songliao basins, which marks an eastwards migration of the depositional and exten- 30 sional centre of the Songliao–Hegang basin system. This eastwards migration implies lithospheric 31 extension driven by palaeo-Pacific roll-back. 32 33 34 35 Zircon grains in clastic sedimentary rocks are and contained China’s largest opencast coal mine 36 derived from the weathering of the surrounding (before 2010) – the Lingbei Opencast Mine, which 37 source rocks, and are recognized as being highly is now part of the Hegang National Mine Park. The 38 resistant to chemical and physical weathering and coal types are mainly bituminous coal to anthracite. 39 other sedimentary processes (Jackson & Sherman The strata of the Hegang Basin were previously con- 40 1953). Detrital zircon analysis is widely recognized sidered to be Late Jurassic in age; however, a recent 41 as a powerful tool for interpreting the provenance study based on palaeontology suggests that they 42 of sedimentary rocks (Drewery et al. 1987; Thomas were deposited in the Early Cretaceous (Sha et al. 43 2011) because it has the ability to link sedimen- 2002). 44 tary basins to their surrounding source regions The Songliao Basin is located between the 45 (Riggs et al. 1996). Detrital zircon analysis can LXR and ZR to the east, and the Great Xing’an 46 also be applied to infer maximum depositional Range to the west (Fig. 1). It is approximately 47 ages of strata (Dickinson & Gehrels 2009), to recon- 1000 km long from north to south, and 400 km 48 struct supercontinent cycles (Li et al. 1995) and to wide from east to west, with a total area of approx- 49 reflect the tectonic settings of the basins in which imately 350 000 km2. The Songliao Basin contains 50 they were deposited (Cawood et al. 2012). oil- and gas-bearing non-marine sedimentary strata, 51 The Hegang Basin is located to the east of the and is one of the largest oil fields in China. It 52 Lesser Xing’an Range (LXR), the Zhangguangcai includes the Daqing oil field, which started pro- 53 Range (ZR) and the Songliao Basin, and lies duction in 1959. The structure and sedimentol- 54 within the Jiamusi Block to the west of the Sanjiang ogy of the Songliao Basin have been well studied 55 Basin, NE China (Fig. 1). It is 100 km long from because of extensive oil and gas exploration and 56 north to south, and 28 km wide from east to west, development (Wu et al. 2007; Feng et al. 2010b, 2 57 with a total area of approximately 2800 km . The 2011). Its structural evolution has been subdivided 58 Hegang Basin has been mined for coal since 1917 into three stages: synrift stage (the Huoshiling, From:Gibson, G. M., Roure,F.&Manatschal, G. (eds) Sedimentary Basins and Crustal Processes at Continental Margins: From Modern Hyper-extended Margins to Deformed Ancient Analogues. Geological Society, London, Special Publications, 413, http://dx.doi.org/10.1144/SP413.2 # The Geological Society of London 2014. Publishing disclaimer: www.geolsoc.org.uk/pub_ethics M. SUN ET AL. 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 Fig. 1. (a) Location of the Central Asian Orogenic Belt (CAOB) and adjacent cratons. (b) Basin distribution in NE 86 China and adjacent areas (after Zhou et al. 2009; Sorokin et al. 2010; Wu et al. 2011): F1, Mudanjiang Fault; F2, Yi-Shu Fault; F3, Dun-Mi Fault; LXR, Lesser Xing’an Range; ZR, Zhangguangcai Range. 87 88 89 Shahezi, Yingcheng and Denglouku formations) detrital zircon geochronology of the Songliao 90 with asthenospheric upwelling and crustal exten- Basin in order to test for any similarities with the 91 sion; post-rift stage (the Quantou, Qingshankou, Hegang Basin. This study will help in understand- 92 Yaojia and Nenjiang formations) with lithosphere ing sedimentary basin development and the tectonic 93 cooling and subsidence; and the structural inversion evolution of East Asia. It is also relevant to the 94 stage (the Sifangtai, Mingshui, Yi’an, Da’an and timing of changes in tectonic regime, associated 95 Taikang formations) with compression and folding with the advance and retreat of the palaeo-Pacific 96 (Ren et al. 2002; Feng et al. 2010a). Plate, which has dominated the architecture of 97 Along the present eastern boundary of the Son- eastern China since the early Mesozoic. 98 gliao Basin, most of the post-rift strata are deep 99 lake facies (Zhang & Bao 2009; Feng et al. 2010a, 100 2013; Gao et al. 2010; Xi et al. 2011; Wang et al. Geological setting 101 2013). This poses some important scientific 102 questions. NE China and adjacent regions in Far East Russia 103 are made up of several massifs and terranes that † Where was the original eastern boundary of the 104 are located between the Siberia and North China Songliao Basin in the post-rift period? 105 cratons (Fig. 1), including the Erguna, Xing’an, † Did the Songliao Basin ever spread east over the 106 Songliao, Bureya and Jiamusi blocks, and the LXR? 107 Sikhote–Alin accretionary complex (Wu et al. † What is the relationship between the Songliao 108 2005; Yu et al. 2008; Kotov et al. 2009; Sorokin and Hegang basins? 109 et al. 2010; Zhou et al. 2011a). The Erguna, 110 In this study, we report a sensitive high-resolution Xing’an and Songliao blocks are considered to be 111 ion microprobe (SHRIMP) zircon U–Pb age of a the eastern part of the Central Asian Orogenic Belt 112 tuff from the Houshigou Formation, and detrital (CAOB) that amalgamated in the Palaeozoic (Xiao 113 zircon ages for the Chengzihe and Houshigou for- et al. 2009, 2010), whereas the Jiamusi block 114 mations of the Hegang Basin. In light of these and Sikhote–Alin accretionary complex are early 115 results, we review the distribution of Late Triassic– Mesozoic circum-Pacific accreted terranes (Zhou 116 Early Jurassic igneous rocks in NE China and the et al. 2009; Wu et al. 2011). The amalgamated EVOLUTION OF CRETACEOUS BASINS, NE CHINA 117 Erguna, Xing’an and Songliao blocks collided (Wu et al. 2011). The Mashan Complex makes 118 with the North China Craton in the Permian (Xiao up the main part of the Jiamusi Block and consists 119 et al. 2003), and with the Siberia Craton in the late of khondalitic rocks with a metamorphic age of 120 Palaeozoic–early Mesozoic (Kravchinsky et al. 500 Ma (Wilde et al. 1999, 2000, 2003). The Hei- 121 2002). Final collision with the Jiamusi Block longjiang Complex is distributed in the western 122 occurred in the early Mesozoic (Zhou et al. 2009), part of the Jiamusi Block, and consists of ultramafic 123 forming the unified Jiamusi–Mongolia block rocks, blueschist-facies pillow basalts, carbonates 124 (Wang et al. 2011). The ocean separating the and mylonitic mica schists, which are considered 125 Jiamusi–Mongolia block from the Siberia Craton to represent a me´lange along the suture between 126 closed completely in the early Early Cretaceous the Jiamusi and Songliao blocks (Wu et al. 2007; 127 (Cogne et al. 2005). Zhou et al. 2009). 128 The Songliao Block is overlain by Mesozoic– 129 Cenozoic strata of the Songliao Basin. Most of the 130 basement beneath the Songliao Basin is composed Stratigraphy and structure of the 131 of Palaeozoic–Mesozoic granitoids and Palaeozoic 132 strata (Wu et al. 2000, 2001; Gao et al. 2007; Pei Hegang Basin 133 et al. 2007; Yu et al. 2008; Zhou et al. 2012), with Stratigraphy 134 minor Proterozoic granitoids (Wang et al. 2006). 135 In the eastern part of the Songliao Block, the base- The basement of the Hegang Basin is composed of 136 ment was uplifted and forms the LXR and ZR, the Mashan and Heilongjiang complexes and Juras- 137 which also contain Palaeozoic–Mesozoic grani- sic granites (Fig.