Abstract
Lithic fragments in the ground layer of the Ata pyroclastic flow deposit, southwestern Japan, were supplied from two different sources. One is the eruptive vent and the other is the basement rock exposed underneath the path of flow. Lithic fragments captured at the eruptive vent gradually decrease in size with distance from the source. Local increases of ML or Md are proportional to increased amounts of captured lithic fragments. The pyroclastic flow eroded basement formations on slopes dipping away from the source, and deposited the lithics within the ground layer on slopes dipping towards the source. The ground layer was found only in the western half of the Ata pyroclastic flow deposit. The absence of the ground layer in the eastern half of the pyroclastic flow deposit is interpreted to result from a selective loss of lithics when the flow traversed a bay or a lake located just east from the vent.
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Suzuki-Kamata, K. The ground layer of Ata pyroclastic flow deposit, southwestern Japan — evidence for the capture of lithic fragments. Bull Volcanol 50, 119–129 (1988). https://doi.org/10.1007/BF01275173
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DOI: https://doi.org/10.1007/BF01275173