Geomorphological classification of post-caldera volcanoes in the Buyan_Bratan caldera, North Bali, Indonesia

6th ITB International Geothermal Workshop

Okuno, Mitsuru^1 ; Harijoko, Agung^2 ; Wayan Warmada, I.^2 ; Watanabe, Koichiro^3 ; Nakamura, Toshio^4 ; Taguchi, Sachihiro^1 ; Kobayashi, Tetsuo^5

Department of Earth System Science, Faculty of Science, Fukuoka University, Fukuoka, Japan^1

Department of Geological Engineering, Gadjah Mada University, Yogyakarta, Indonesia^2

Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan^3

Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan^4

Kagoshima University, Kagoshima, Japan^5

关键词: Bali , Indonesia;    Coarse-grained;    Debris avalanche deposits;    Eastern side;    Holocenes;    Lava flows;    Tephras;    Volcano eruptions;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/103/1/012014/pdf
DOI  :  10.1088/1755-1315/103/1/012014

来源: IOP

【 摘 要 】

A landform of the post-caldera volcanoes (Lesung, Tapak, Sengayang, Pohen, and Adeng) in the Buyan-Bratan caldera on the island of Bali, Indonesia can be classified by topographic interpretation. The Tapak volcano has three craters, aligned from north to south. Lava effused from the central crater has flowed downward to the northwest, separating the Tamblingan and Buyan Lakes. This lava also covers the tip of the lava flow from the Lesung volcano. Therefore, it is a product of the latest post-caldera volcano eruption. The Lesung volcano also has two craters, with a gully developing on the pyroclastic cone from the northern slope to the western slope. Lava from the south crater has flowed down the western flank, beyond the caldera rim. Lava distributed on the eastern side from the south also surrounds the Sengayang volcano. The Adeng volcano is surrounded by debris avalanche deposits from the Pohen volcano. Based on these topographic relationships, Sengayang volcano appears to be the oldest of the post-caldera volcanoes, followed by the Adeng, Pohen, Lesung, and Tapak volcanoes. Coarse-grained scoria falls around this area are intercalated with two foreign tephras: the Samalas tephra (1257 A.D.) from Lombok Island and the Penelokan tephra (ca. 5.5 kBP) from the Batur caldera. The source of these scoria falls is estimated to be either the Tapak or Lesung volcano, implying that at least two volcanoes have erupted during the Holocene period.