強磁性鉱物の熱磁化特性によるテフラの同定

For identificate and correlate the Quaternary tephras, the thermomagnetic properties of ferromagnetic minerals contained in the Daisen tephra formation re analysed by means of thermomagnetic balance. The investigates outcrop is 16km northeast of the Daisen volcano. At the outcrop, ten pumice fall layers and eight ash fall layers are exposed. Almost all these tephra layers are very thin and remarkably weatherd because the outcrop is situated apart from their disrutibution axes.The results of the thermomagnetic analysis show that these thin and weathered tephras are completely corelated to thick and more fresh tephras of their main distribution area. The thermomagnetic properties of ferromagnetic minerals including the Curie temperature are effective indicators for identification of tephra layers.