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Of Fugendake Volcano in Unzen , Sw Japan
| Content Provider | Semantic Scholar |
|---|---|
| Author | Xu, Sheng Ming Hoshizumi, Hideo Uto, Kozo Freeman, Stewart P. H. T. |
| Copyright Year | 2013 |
| Abstract | This article presents new radiocarbon ages for the lavas, pyroclastic flow, and lahar deposits that originated from the Fugendake and Mayuyama volcanoes of the Younger Unzen Volcano, SW Japan. Nine charcoal samples were collected from the lavas and pyroclastic flow deposits, and 17 soil samples from the underlying volcanic-related products. This data set, together with previously published ages (thermoluminescence, K-Ar, fission track, and 14C), yielded new information about the timing of Late Pleistocene eruptions and an improved understanding of the evolution of the Fugendake and Mayuyama volcanoes. Fugendake Volcano started to build within the scar of Myokendake around 29 cal ka BP, and its eruption products spread over the flank of Myokendake. The remarkable eruptions of Fugendake Volcano included the lava and pyroclastic flow deposits around 22, 17, 12, and 4.5 cal ka BP. Subsequent historical eruptions occurred in AD 1663, 1792, and 1991–1995. Developed on the eastern extension of Fugendake Volcano, Mayuyama Volcano was active during the building stage of Fugendake at 4.5 cal ka BP. This study also identified a pumice eruption at ~10 ka and 2 volcanic-related lahar deposits around 1.6 and 0.7 ka, which need to be addressed in future research. INTRODUCTION Unzen Volcano is situated in an active graben, approximately 70 km west of the volcanic front of SW Japan (Figure 1). It began ~500 ka ago, and the latest eruption occurred in 1991–1995. The composite volcanic edifice can be subdivided into the Older (500–150 ka) and Younger Unzen volcanoes (150–0 ka). The latter comprises the Nodake, Myokendake, Fugendake, and Mayuyama volcanoes (Watanabe and Hoshizumi 1995; Hoshizumi et al. 1999). Geological observation suggested that Fugendake Volcano was built within the horseshoe-shaped scar of Myokendake, and its eruption products spread over the flank of Myokendake (Figure 2). Nodake is an isolated volcanic center adjacent to Myokendake. Mayuyama is completely isolated from these 3 volcanoes. 1Scottish Universities Environmental Research Centre, East Kilbride G75 0QF, United Kingdom. 2JAEA Tono Geoscience Center, Toki, Gifu 509-5102, Japan. Corresponding author. Email: s.xu@suerc.gla.ac.uk. 3Geological Survey of Japan, Tsukuba, Ibaraki 305-8567, Japan. Figure 1 Location of Unzen Volcano. Solid triangles denote active volcanoes. Those distributed along the volcanic front are typical island-arc type volcanoes caused by the Philippine Sea plate subducting beneath SW Japan, while the Unzen volcanoes are considered to relate to the active graben development in last 500 ka. 34oN 130oE 132oE |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://journals.uair.arizona.edu/index.php/radiocarbon/article/download/16207/pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
