Affiliation:
1. Kangwon National University
2. Korea Institute of Geosciences and Mineral Resources
3. Sunchon National University
4. Pusan National University
Abstract
Abstract
It was recently reported that a Quaternary basin in southeastern Korea was formed by a meteorite impact, and a 12-cm-thick tephra layer was found in lake sediments in this basin. In this study, we analyzed the geochemical composition and refractive index of glass shards to identify the unknown tephra. Based on both results, this tephra was identified as Kb-Ks tephra that erupted in the Kyushu area, Japan, approximately 520 ka. To our knowledge, this is the first report of Kb-Ks tephra in terrestrial sediments in the Korean Peninsula. These findings indicate that the depositional age of the lake sediments is much older than previously suspected (ca. 63 ka), and that the meteorite impact occurred before 520 ka. Although more detailed studies are needed, the discovery of Kb-Ks tephra provides important information concerning the paleoclimate during the middle Pleistocene, as well as the prediction of volcanic hazards in the Korean Peninsula.
Publisher
Research Square Platform LLC
Reference22 articles.
1. Radiocarbon ages and environments of deposition of the Wono and Trego Hot Springs tephra horizons in the Pyramid Lake Subbasin, Nevada;Benson LV;Quaternary Research,1997
2. New fission-track age determinations on impact glasses;Bigazzi G;Meteoritics & Planetary Science,1996
3. Borchardt, G.A., Aruscavage, P.J., and Millard Jr., H.T., 1972, Correlation of Bishop Ash, a Pleistocene marker bed, using instrumental neutron activation analysis. Journal of Sedimentary Petrology, 42, 301–306. Carson et al., 2002
4. Chang, K.H., 1968. Explanatory Text of the Geological Map of Habcheon Sheet (1:50,000) Geological Survey of Korea. 21 p. (in Korean with English summary)
5. An improved system for measuring refractive index using the thermal immersion method;Danhara T;Quaternary International,1992