A Review of the Holocene Major Eruption of Mt. Paektu Volcano

摘要: A Holocene volcanic ash layer comprising abundant glass shards occurs as near-surface in north Tohoku and Hokkaido, Japan. This has been given a name "Baekdusan-Tomakomai (B-Tm)". Detailed petrographic observation accurate determinations of the refractive indices several phenocrysts phases tephra, together with extensive field work, have led to conclusion that B-Tm is product single major eruption Cheonji caldera, Mt. Paektu event exalts tephra one greatest volcanism world. The from trachydacitic trachyrhyolitic composition contains bubble-walled pumice type alkali-feldspar phenocrysts. index ranges n=1.511 1.522, alkali-feldspar, 1.523. thickness contour its grain-size distribution clearly indicate this widespread represents ejecta Paektu, which largest calderas Korea an approximate diameter 4.0 ㎞. Various carbon dates obtained so far, ranging rather widely ca. 850±20 y.B.P. 1410±80 Besides, stratigraphical relationships human remains North Japan give probable age between A.D.915 A.D. 1334. marker thus extremely significant for correlation medieval archaeological sites Northeast Asia restoration natural changes thin area.