Geological Background and Geodynamic Mechanism of Mt
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Lithos 236–237 (2015) 46–73 Contents lists available at ScienceDirect Lithos journal homepage: www.elsevier.com/locate/lithos Geological background and geodynamic mechanism of Mt. Changbai volcanoes on the China–Korea border Jia-qi Liu a, Shuang-shuang Chen a,b,⁎,Zheng-fuGuoa, Wen-feng Guo a,b, Huai-yu He a, Hai-tao You c, Hang-min Kim d, Gun-ho Sung d,HaenamKimd a Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China b University of Chinese Academy of Sciences, Beijing 100049, China c Key Laboratory of Computational Geodynamics, Faculty of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China d Institute of Volcano, State Seismological Bureau, Democratic People's Republic of Korea article info abstract Article history: The intense Cenozoic volcanism of Mt. Changbai provides a natural laboratory for investigating the characteristics Received 12 November 2014 of volcanism and the dynamical evolution of the Northeast Asian continental margin. Mt. Changbai volcanoes Accepted 3 August 2015 predominantly consist of Wangtian'e volcano in China, Tianchi volcano spanning China and DPR Korea, and Available online 28 August 2015 Namphothe volcano in DPR Korea. Geochronology data and historical records of volcanism indicate that the three eruption centers were formed in the following sequence: Wangtian'e volcano to Namphothe and Tianchi Keywords: volcano, advancing temporally and spatially from southwest to northeast. The three eruption centers of Mt. China and Korea Re-eruption Changbai volcano are located close together, have similar magma evolution trends, bimodal volcanic rock distri- Mt. Changbai bution, and an enriched mantle source, etc. Although the Cenozoic volcanism in Mt. Changbai is thought to be Northeast Asia somewhat related to the subduction of the Western Pacific Plate, the regularity of volcanic activity and petrogra- Volcanism phy characteristics have continental rift affinity. We therefore conclude that the occurrence of synchronous and similar volcanic activity on both sides of the Japan Sea (i.e., the Japan Arc and Northeast China) likely respond to the rift expansion and the back-arc spreading of Japan Sea. From many perspectives, Mt. Changbai volcano is a giant active volcano with hidden potentially eruptive risks. © 2015 Elsevier B.V. All rights reserved. 1. Introduction late Quaternary (e.g., Liu et al., 2001; Siebert et al., 2010; Wang et al., 2003; Wei et al., 2013). Geological investigations of Mt. Changbai can Mt. Changbai volcano (also named as Baitoushan, Baegdusan or be traced back to the 1980s, and since then the petrology, geochemistry, Paektusan volcano; E 127°00′–129°00′, N 41°20′–42°40′) predominant- and geochronology of the volcanic rocks have gradually been studied ly comprises Wangtian'e volcano (WV) in China, Tianchi volcano (TV) (Basu et al., 1991; Cao et al., 1998; Fan et al., 1998, 1999; Jin and Lin, on the China–DPR Korea (Democratic People's Republic of Korea) bor- 1995; Liu, 1983, 1999; Liu and Wang, 1982; Liu et al., 1996, 1998a,b; der, and Namphothe volcano (NV) in DPR Korea. Mt. Changbai volcano Ri, 1993; Wang et al., 1983; Xie et al., 1988). Although scientists have is one of the most typical, active, and dangerous volcanoes both in carried out a great deal of research on the Mt. Changbai volcanoes in northeast Asia and globally (Fan et al., 1998, 1999, 2007; Liu, 1983, China, the investigations of Mt. Changbai on the DPR Korean side have 1999; Stone, 2010, 2011; Wang et al., 1983; Wei et al., 2013). Although been very limited (Cao et al., 1998; Fan et al., 2005; Jin and Lin, 1995; the volcano has not erupted in the past 100 years, there is potential for Jin et al., 2000; Ri, 1993; Stone, 2010, 2011). However, an improved un- future eruptions because the dormancy time is now hundreds of years, derstanding of the DPR Korean part of Mt. Changbai is of prime impor- which is consistent with the volcanic eruption cycle (Chu et al., 2011; tance because the various regions of Mt. Changbai are closely related Guo et al., 2005; Horn and Schmincke, 2000; Oppenheimer, 2003; and the Namphothe and Tianchi eruption centers are located in the Stone, 2010, 2011; Taniguchi, 2004; Wei et al., 2013; Xu et al., 2012a; DPR Korea and possess good field outcrops and complete eruptive se- Yamada et al., 2007; Yin et al., 2012). Mt. Changbai area is characterized quences (Liu, 1999; Stone, 2010, 2011). Fortunately, thanks to the strong by the Tianchi-centered volcanic field, which comprises extensive support of both governments, our team established a cooperative agree- Cenozoic basalts that erupted between the early Paleogene and the ment for joint research on the Mt. Changbai volcanoes. In the early 21st century, at the invitation of DPR Korea, we were the first research team to carry out fieldwork and sampling in the DPR Korean part of the volca- ⁎ Corresponding author at: Key Laboratory of Cenozoic Geology and Environment, nic complex. So far, we have conducted three detailed field geological in- Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China. Tel.: +86 10 82998626; fax: +86 10 62010846. vestigations and collected hundreds of volcanic samples, laying a solid E-mail address: [email protected] (S. Chen). foundation for further investigations of Mt. Changbai volcanoes. http://dx.doi.org/10.1016/j.lithos.2015.08.011 0024-4937/© 2015 Elsevier B.V. All rights reserved. J. Liu et al. / Lithos 236–237 (2015) 46–73 47 In general, the products of the three volcanic centers (i.e., Wangtian'e, Tianchi and Namphothe) have similar materials and eruptive se- quences, suggesting that they were derived from a common source and/or had similar eruption processes (Chen et al., 2008; Fan et al., 1998, 1999, 2007; Ri, 1993). However, the diversity of the eruption age, scale, characteristics, and eruption products indicate distinct erup- tion styles and/or heterogeneity of the mantle source and magma as- cent process. Many key questions are not yet perfectly answered, such as the following: what is the relationship between these three eruption centers and the adjacent volcanoes? What was the eruptive sequence of the three centers? How did the volcanic activity migrate in time and space? What was the dynamic mechanism for the eruption of Mt. Changbai volcano? On the other hand, similarities in the frequency and intensity of Miocene–Holocene volcanism have been observed on both sides of the Japan Sea (e.g., northeast China and the Japan Arc; Liu, 1999; Liu et al., 2001). The reason for this similarity in volcanic activity in northeast China and the Japan Arc is another interesting research question (Liu, 1999). If this volcanism regularity (similar volcanic activities) is still ac- tive at the present day, does this volcanism reappear in a similar way on both sides of the Japan Sea (Liu et al., 2001)? Additionally, because Mt. Changbai region is inhabited by more than 100,000 people and is also an area of economic development for agriculture, forestry, and tourism, the possibility of a renewed eruption of the Mt. Changbai volca- noes and resulting potential damage are important issues (Stone, 2010, 2011; Wei et al., 2003, 2013). To solve these above questions, further re- search need to be conducted. Previous studies on Mt. Changbai focused mainly on the volcanic geology, rock type, petrogenesis, magma evolu- tion, and eruptive mechanisms (e.g., Cao et al., 1998; Chen et al., 2007, Chen et al., 2008; Fan et al., 1998,1999, 2001, 2006, 2007; Jin and Lin, 1995; Jin et al., 2000; Liu and Wang, 1982; Liu et al., 1996, 1998a,b; Ri, 1993; Wei et al., 2007, 2013), whereas there have been limited studies on the relationship between the Mt. Changbai volcanoes and the volca- nism of the NE China continental rift system and Japan Arc, deep asthenosphere process, dynamic mechanism of volcanic eruption in NE Asia as a whole, and potential future eruptions of Mt. Changbai volcanoes (Stone, 2010, 2011; Sun et al., 2014; Wei et al., 2003, 2013). 2. Geological background Mt. Changbai volcano lies in the uplifted area between the Japan Sea back-arc basin and the Songliao Basin (Fig. 1a). The volcano covers an area of 12,000 km2 and is characterized by the presence of three main eruptive cones (i.e., Wangtian'e, Tianchi, and Namphothe), with the el- evation gradually decreasing from the crater to the surrounding area (Fig. 1b). Tianchi is located in the central zone of Mt. Changbai volcano, and Wangtian'e and Namphothe are 35 km southwest of Tianchi and 45 km southeast of Tianchi, respectively (Fig. 1b; Fan et al., 2007; Wei et al., 2003, 2004, 2007). The main peak of Tianchi (2749 m) is charac- terized by a large crater lake and a composite volcano, which was created by many volcanic eruptions. Compositionally, Tianchi mainly comprises basalts in the lava plateau, trachytes in the cone, and Fig. 1. a. Simplified geological map of northeast Asian continental margin. b. The full view of pantellerites at the summit (Fig. 1c; Fan et al., 2001, 2005, 2006, 2007; Mt. Changbai volcanoes, the landscape map of Wangtian'e, Tianchi and Namphothe Liu and Wang, 1982; Liu et al., 1996, 1998a,b; Wang et al., 1983, Wang volcanoes (WV, TV, NV), and the detailed sampling points. c. Different lithologies include ba- saltic flow, trachyte and pantellerite, and each kind of lithology represents different phases et al., 2003; Wei et al., 2004, 2007, 2013). Wangtian'e volcano of volcanic eruption, such as early basaltic flow as lava plateau, followed by trachyte com- (2051 m) consists of an early-stage basalt–trachybasalt platform, a posing of volcanic cones, and finally pyroclastic deposits covering the tops of the mountains.