Luminescence property in a stalagmite from Okgye Cave and applicability for paleoclimate research

초록

Luminescence properties in speleothems have been widely used for high-resolution paleoclimate studies combined with stable isotope and trace element records. However, luminescence in Korean speleothems has not been reported before, and there is no research on it. Here, we describe luminescence properties of a stalagmite (OG1) from Okgye Cave, South Korea, using confocal laser scanning microscopy (CLSM) and discuss its applicability for the paleoclimate research. The stalagmite exhibits lithology-dependent luminescence properties, including crystal habit, and preserves luminescence lamination consisting of couplets of bright and non-luminescent bands. Based on previous reports, luminescence in speleothems is mostly caused by sufficient water infiltration to transport soil-derived organic matter into the cave. Therefore, the bright luminescent band in OG1 would have formed during summer rainy season, when extreme rainfall events occur over the Korean Peninsula. This study suggests that luminescence properties of Korean speleothems may provide information on seasonal paleoclimatic changes during the growth, and can also be used to improve geochronological uncertainty with an incremental age dating method.

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