黒富士火山の火山層序学的研究

概要

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Kurofuji volcano of the Lower Pleistocene in age stands at the northern margin of the Kofu basin, Central Japan. The products of that volcano cover an extensive area more than 217 km2, and are characterized by the presence of ash-flow fields of large scale and radial dikes. The products of that volcano consist of the Kurofuji pyroclastic flows, the Kurofuji Dikes and the Kayagatake lavas in order of eruptive activity. The first, the Kurofuji pyroclastic flows of dacite which occupied more than 32.5 km^3 in total volume had been brought by fissure eruption(F). They are divided into five units by litho-facies, each of which consists of multiple-flow compound cooling units. Therefore, the activity of the pyroclastic flows is classified into five stages and is characterized by less pyroclastic falls and no lava flow. Succeeding to that activity, the Kurofuji dikes had built up many domes of dacite at the central area of the preceding pyroclastic flows effusion. Nowadays, the dikes display a typical radial pattern due to the severe dissection. The last, the Kayagatake lavas which form a small strato-volcano on the western slope of Kurofuji volcano had been derived mainly from the central eruption of two-pyroxene andesite.
地学団体研究会の論文
1967-05-25