Quaternary Volcanoes and Widespread Tephras of the World
キーワード:
co-ignimbrite ash,
flood basalt,
ignimbrite,
plate tectonics,
Quaternary,
tephra catalogue,
widespread tephra
2002 年 6 巻 2 号 p. 3-17
詳細
2002 年 6 巻 2 号 p. 3-17
It is the two contrasting volcanic products, flood basalt and silicic ignimbrite, that represent the largest known volcanism in the earth history. The former is a product of effusive eruption at hot spots and divergent plate margins, forming extensive lava plains and shield volcanoes. On the other hand, the ignimbrite is usually associated with large calderas on the conversion boundary and continental rift, forming ignimbrite sheets and co-ignimbrite volcanic tephras. Many extraordinarily large tephras have been recognized not only on land but also from abyssal sediments. This paper particularly focuses on the significance of Quaternary widespread tephras. A catalogue of the large volume tephras of the Quaternary around the world is tentatively listed, because they are very powerful tools for corelating stratigraphic sequences and landforms extensively, particularly for land-sea correlation. Continual revision and supplement action for compilation of the tephra catalogue will be a task for future studies.
