Temperature estimation of pyroclastic deposits by natural remanent magnetism

Abstract

A uniform orientation of remanent magnetism in clastic volcanic rocks implies that the deposits formed at temperatures above the Curie point of the constituent ferromagnetic minerals, the direction of magnetism paralleling that of the geomagnetic field at the time of cooling, whereas random orientation implies formation below the Curie point. The results of measurements on mud flow and nuee ardente deposits from various Japanese localities are given.