Holocene Environmental Changes in the Shirone Area of the Echigo Plain, Central Japan

摘要

Sedimentary facies and fossils from a drilling core(Shirone 9-4 core) were examined in order to elucidate stratigraphical change in the Holocene environments in the Shirone area, Echigo Plain, central Japan. Holocene sediments of the core are divided into four sedimentary units, U-I, U-II, U-III, and U-IV in descending order. Four molluscan (M-1 to M-4), four foraminiferal (F-1 to F-4) and thirteen diatom (D-1 to D-13) divisions were established based on the combination of characteristic species and frequency of occur- rence in each taxa.