Abstract
The Donzurubo subaqueous pyroclastic flow deposits deposited in subaqueous environments maintaining high temperatures (about 500°C).
Each flow unit of these pyroclastic flow deposits shows some characteristic size distributions in its stratigraphic column. The concentration of pumice at the top clearly defines the top facies of a flow unit. Median diameter (Md Ø) and the averages of the largest ten essential dense debris increase gradually starting from both the top and the bottom of the flow unit. The maximum points of Md Ø and the averages of the largest ten essential dense debris are usually found in the middle zone of each flow unit, but the Md Ø maximum points are generally in a lower position than the averages. Mechanical analyses show that the deposits consist of polymodal populations. They show, on the whole, an asymmetrical distribution, which is mainly due to the absence of the coarser fractions of the main population. The size distribution characteristics and the C-M pattern of the deposits suggest that these subaqueous pyroclastic flow deposits were not originated by homogeneously suspended turbulent flows but by incandescent turbulent flows with layered suspension.
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References
Aramaki, S., 1969,Geology and pyroclastic flow deposits of the Kokubu area, Kagoshima Prefecture. Jour. Geol. Soc. Japan,75, p. 425–442 (in Japanese).
Fiske, R. S., 1969,Recognition and significance of pumice in marine pyroclastic rocks. Bull. Geol. Soc. Amer.,80, p. 1–8.
Goldsmith, H. L. andMason, S. G., 1961,Axial migration of particles in Poiseuille flow. Nature,190, p. 1095–1096.
Karnis, A., Goldsmith, H. L. andMason, S. G., 1963,Axial migration of particles in Poiseuille flow. Nature,200, p. 159–160.
Kato, I., Muroi, I., Yamazaki, T. andAbe, M., 1971,Subaqueous pyroclastic flow deposits in the Upper Donzurubo Formation, Nijo-san district, Osaka, Japan. Jour. Geol. Soc. Japan,77, p. 193–206.
Macdonald, G. A. andAlcaraz, A., 1956,Nuée ardentes of the 1948–1953 eruption of Hibok-Hibok. Bull. Volcanol., Ser. 2,18, p. 169–178.
MacGregor, A. G., 1952,Eruptive mechanism: Mt. Pelée, the Soufrière of St. Vincent and the Valley of Ten Thousand Smokes. Bull. Volcanol., Ser. 2,12, p. 49–74.
Morimoto, R., Huzita, K., Yoshida, H., Matsumoto, T., Ichihara, M. andKasama, T., 1953,Geology of Nijo-san. Earth Science (Chikyu Kagaku), No. 11, p. 1–12 (in Japanese).
Murai, I., 1961,A study of the textural characteristics of pyroclastic flow deposits in Japan. Bull. Earthq. Res. Inst. Tokyo Univ.,39, p. 133–248.
Muroi, I., 1968,Application of an automatically recording method to the astatic magnetometer. 1968 Annual Prog. Rept. Palaeogeophysics Research in Japan, p. 73–78.
Oliver, D. R., 1962,Influence of particle rotation on radial migration in the Poiseuille flow of suspensions. Nature,194, p. 1269–1271.
Passega, R., 1964,Grain size representation by C-M patterns as a geological tool. Jour. Sed. Petrol.,34, p. 830–847.
Sheridan, M. F., 1971,Particle-size characteristics of pyroclastic tuffs. Jour. Geophy. Res.,76, p. 5627–5634.
Smith, R. L., 1960a, Ash flows. Bull. Geol. Soc. Amer.,71, p. 795–842.
-----, 1960b,Zones and zonal variations in welded ash flows. U. S. Geol. Survey Prof. Paper, 354-F, p. 149–159.
Walker, G. P. L., 1971,Grain-size characteristics of pyroclastic deposits. Jour. Geol.,79, p. 696–714.
Yamazaki, T. andOnuki, H., 1969,Differentiation of the calc-alkaline magma at Nijo-san district, Osaka. Jour. Japan. Assoc. Miner. Petrol. Econ. Geol.,62, p. 249–263 (in Japanese).
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Yamazaki, T., Kato, I., Muroi, I. et al. Textural analysis and flow mechanism of the Donzurubo subaqueous pyroclastic flow deposits. Bull Volcanol 37, 231–244 (1973). https://doi.org/10.1007/BF02597132
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DOI: https://doi.org/10.1007/BF02597132