Reconstructing Paleoenvironment of Hanon Paleo-Maar Lake in Jeju Island during the Last Deglaciation using Diatom Analysis

Hanon maar paleolake, in the southern part of Jeju Island, Korea, is located in a geographically significant place that can provide the missing link to the paleoenvironment between Japan and China because the southern part of Jeju Island is influenced by the East Asia monsoon and the Kuroshio Current. This study is the first to examine a lacustrine environment during the last deglaciation of Hanon through diatom analysis. We investigated water depth, trophic status, saprobity, water temperature and the acidification from 90 to 250cm of the 10-meter-long sediment core (HN-1) covering 15,500 - 8,000 cal. yr BP in detail. The time table of the climate shifts in Hanon maar which is reconstructed in this study corresponds with other studies of Hanon maar paleoclimate. However, our results distinguish the Bølling and Allerød separately, which was not observed in previous studies [Chung 2007; Park et al. 2014a; Park et al. 2014b]. Overall, Hanon maar paleoenvironment during the last deglaciation has changed as follows: cold and dry for the Oldest Dryas, increasing temperatures and moisture for the Bølling-Allerød, cold and wet-dry for the Younger Dryas, an increase in temperatures and temporarily drier for the Preboreal, and warm and dry/wet for the Boreal. It was possible to reconstruct the paleo-lacustrine environment of Hanon maar paleolake during the last deglaciation using diatom analysis, and it suggested a new proxy data for the paleoenvironment/paleoclimate in freshwater environment in Korea.