Climatic stages recorded in sediments of the Gunang Cave, South Korea

摘要

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 elastics and hardpan speleothems. The sediments compose a 4 m thick lens near the cave entrance. The lens formed during the Middle-Late Pleistocene and Holocene according to ~(14)C and U-Th 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 60-65%. The amount of the wind-blown component 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.