Climatic stages recorded in sediments of the Gunang Cave, South Korea J.Y. Kim a , S.K. Krivonogov a, b, * , Y.J. Lee c , J.Y. Woo c , K.C. Oh d , D.Y. Yang a , J.C. Kim e , I.Y. Safonova a, b , M. Yamamoto f a Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, South Korea b Institute of Geology and Mineralogy SB RAS, Novosibirsk 630090, Russia c Korea Institute of Prehistory Cultural Heritage, Cheongju 360-812, South Korea d Quaternary Environment Research, Daejeon 305-340, South Korea e Seoul National University, Seoul 151-742, South Korea f Kanazawa University, Kanazawa 920-1192, Japan article info Article history: Available online 16 May 2013 abstract This paper presents and analyses lithological, stratigraphic and geochronological data on the Gunang cave, which is an important archaeological site in South Korea. It discusses problems of the age and origin of its sedimentary sequence, which consists of clastics and hardpan speleothems. The sediments compose a 4 m thick lens near the cave entrance. The lens formed during the MiddleeLate Pleistocene and Holocene according to 14 C and UeTh dating. The changes of cave environments are reconstructed based on sedimentological, palynological, mineralogical, magnetic and geochemical data. The clastic sediment unit consists of roof-fallen limestone debris cemented by fine-grained matrix. The matrix is dominated by silt (80%), which aeolian component is 60e65%. The amount of the wind-blown compo- nent is persistent throughout the clastic layers suggesting a relatively stable depositional process in dry environment. In contrast, three lime-cemented hardpans formed in a wet environment of groundwater seepage. The revised age model suggests that the hardpans formed in early MIS1, MIS 5.5, and MIS 7, and therefore correspond to the wetness maximums of these warm stages. Ó 2013 Elsevier Ltd and INQUA. All rights reserved. 1. Introduction Cave sediments and speleothems are well-known sources of information about environmental and climatic changes in terms of precipitation and atmospheric circulation. In South-East Asia, speleothems have been studied as important natural archives of millennium- to orbital-scale evolution of the East Asian monsoon, which is the main force of climate variability (e.g., Wang et al., 2001; Yuan et al., 2004; Dykoski et al., 2005; Kelly et al., 2006; Rohling et al., 2009). Geochemical and paleontological studies of cave clastic deposits have gone a long way towards providing a better understanding of climatic signals (Campy and Chaline, 1993; Polk et al., 2007; Sasowsky and Mylroie, 2007; Finlayson et al., 2008). Moreover, cave sediments have been studied in detail in terms of geoarchaeology (Ellwood et al., 2001; Madeyska, 2002; Hunt et al., 2010). There are more than 1000 caves in karst areas of the Korean Peninsula (Woo et al., 2005), which have been studied for reconstructing paleoenvironment and paleoclimate, and for geo- archeology. Evidence for several stages of increased moisture supply comes from the study of speleothems in Korea (Woo and Won, 1989; Choi et al., 2003; Jo et al., 2010, 2011). Cave clastic sediments have been studied mainly in relation to archeological excavations. There are 56 archaeologically important caves in Korea (Cho, 2006) and some, like the Gunang Cave, which is the subject of this study, host Paleolithic human fossils and tools (e.g., Lee et al., 2003; Park, 2006). The results of those archaeological excavations and research were published mostly in Korean journals and special reports (e.g., Sohn et al., 1980, 1991; Lee, 1984; Kim et al., 2004, 2005) and therefore are hardly accessible to the world scientific community. In terms of paleoclimate, the caves of South Korea have been studied to a lesser degree. Lim et al. (2011) presented carbon isotope proxies for the past changes of vegetation and moisture supply over the last 40,000 years obtained from sediments of the Cheongok Cave and concluded that the changes of C 4 plant abun- dance resulted from both strong Asia summer monsoons and sea- level driven oceanic circulation changes in the East Sea. Two ma- jor stages of increased moisture supply at MIS 1 and MIS 5.5 were considered by Jo et al. (2011), who studied speleothems of the * Corresponding author. Institute of Geology and Mineralogy SB RAS, Koptyuga Ave. 3, Novosibirsk 630090, Russia. E-mail address: s_krivonogov@mail.ru (S.K. Krivonogov). Contents lists available at SciVerse ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint 1040-6182/$ e see front matter Ó 2013 Elsevier Ltd and INQUA. All rights reserved. http://dx.doi.org/10.1016/j.quaint.2013.05.013 Quaternary International 313-314 (2013) 194e209