Article https://doi.org/10.1007/s12303-019-0010-2 pISSN 1226-4806 eISSN 1598-7477 Geosciences Journal GJ Quartz OSL dating of palaeosols intercalated with basaltic lava flows and scoria deposits from monogenetic volcanoes in northeastern Jeju Island, Korea Eun-Young Yeo 1,2 , Jeong-Heon Choi 2 *, Ung San Ahn 3 , and Albert Chang-sik Cheong 1,2 1 Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea 2 Division of Earth and Environmental Sciences, Korea Basic Science Institute, Chungbuk 28119, Republic of Korea 3 World Heritage Office, Jeju Special Self-Governing Provincial Government, Jeju 63341, Republic of Korea ABSTARCT: Jeju Island, which lies on the continental shelf in the southern Korean Peninsula, is the emergent portion of a basaltic volcanic field that has erupted since the Early Pleistocene (ca. 1.8 Ma). Volcanic activity that continued into historic times (ca. 1 ka) formed an elongated shield with a central edifice (Mt. Halla) and more than 300 monogenetic cones and rings. The estab- lishment of a temporal framework for Jeju volcanism, particularly during the Late Pleistocene and Holocene activities, requires geo- chronological tools other than radiometric dating techniques, which are based on parent-daughter isotope pairs with geologically long half-lives, such as 40 Ar/ 39 Ar dating. In this study, we conducted quartz optically stimulated luminescence (OSL) dating of palae- osols intercalated with basaltic lava flows and scoria deposits, presumably ejected from three monogenetic volcanoes (Cheoreum, Darangsh and Dunjibong volcanoes) in the northeastern part of the island. Quartz extracts from the palaeosols had moderate to dim sensitivity to optical stimulation, but several prerequisite tests of the measurement protocols for equivalent dose estimation were successful. The coarse (63–250 μm) and fine (4–11 μm) quartz fractions yielded continuous wave (CW)-OSL ages of 19.9– 7.0 and 18.6–6.7 ka, respectively, both of which were broadly consistent with the radiocarbon dates (10245–7440 Cal yr BP). These ages indicate that lava flows and scoria deposits covering the palaeosols are younger than ~7 ka. The pulsed OSL signals in coarse quartz extracts from the palaeosols suffered from poor counting statistics, thus it is recommended that they not be applied solely (i.e., without any other absolute ages to compare) to dating dim samples. From one of the sites investigated here, the averaged sed- imentation rate of the palaeosol is estimated to be ~0.05 mm/yr, based on stratigraphically consistent CW-OSL ages. The OSL ages presented in this paper, together with previous OSL and radiocarbon ages, confirm that Jeju volcanic island was regionally active during the Holocene. Key words: Jeju Island, monogenetic volcanoes, palaeosol, OSL, Holocene Manuscript received December 27, 2018; Manuscript accepted March 1, 2019 1. INTRODUCTION Recent advances in luminescence dating method have considerably expanded its applicability in terms of datable age range (e.g., Thiel et al., 2012; Li et al., 2013; Sun et al., 2017) and materials to be dated (e.g., Sohbati et al., 2015; Jenkins et al., 2018; Gliganic et al., 2019). However, establishing a geochronology of volcanic rocks and related sediments using luminescence dating methods remains challenging, mainly due to the lack of dosimeter minerals, quartz and K-rich feldspars. Even where quartz and feldspars exist in volcanic materials, they have been reported to show various undesirable luminescence characteristics for reliable dating; for instance, since earlier, it has been observed that luminescence signals in “volcanic quartz” are dominated by non-fast optically stimulated luminescence (OSL) components (Tsukamoto et al., 2003; Choi et al., 2006), which may result in significant OSL age underestimation (Bonde et al., 2001). Tsukamoto et al. (2011) have performed intensive works to assess the possibility of luminescence dating of basaltic rocks that contain plagioclase feldspars. Despite their success in dating young basaltic rocks after correcting for anomalous fading (~10–14 ka), the reports *Corresponding author: Jeong-Heon Choi Division of Earth and Environmental Sciences, Korea Basic Science Institute, 162 Yeongudanji-ro, Cheongwon-gu, Cheongju, Chungbuk 28119, Republic of Korea Tel: +82-43-240-5333, Fax: +82-43-240-5179, E-mail: jhchoi@kbsi.re.kr The Association of Korean Geoscience Societies and Springer 2019