A Late Pleistocene Tephra Layer Containing Biotite and Cummingtonite in the Northern Part of Yamagata Prefecture, Northeast Japan

摘要

Dokusawa Tephra (Dks) is distributed in the northern part of Yamagata Prefecture, North- east Japan. This study clarifies its petro- graphic properties, stratigraphic position, and distribution. It also discusses the locations of source vents and the eruptive age of Dks, and suggests a tentative correlation of Dks with specific tephra distributed in neighboring regions. The conclusions are as follows.