Geomorphology of Volcanic Mud-flows in the Area around Iwaki Volcano

Abstract

Mount Iwaki is a Volcano 1625m high, in the western part of Aomori Prefecture. The author has made a survey of the area covered by volcanic mud-flows around this volcano. The main results are as follows:1. The material ejected from Iwaki Volcano consist s of the lava and agglomeratic rocks in Diluvium and various volcanic mud-flows and volcanic ash in Alluvium.2. The volcanic mud-flows are classified into three types: namely sandy flows, ashy flows and volcanic detritus flows, according to the types of main ejecta.3. The author has classified volcanic mud-flows of Iwaki Volcano into five. Those are Sasamori mud-flow, Odaino mud-lfow, Tozurasawa mud-flow, Yayoi mud-flow and Hyakuzawa-mud-flow, named after the the typical localities they are distributed.4. Around the Iwaki Volcano, the detritus flows are distributed widely on the northern foot, the ash-flows on the eastern foot, and the sand-flows on the southern foot.5. The area covered by the order of the ejection of the mud-flows is shown in Fig 5.6. The area covered by the mud-flows around Iwaki Volcano is smaller than those around Volcanoes Iwate and Bandai.