Volcanic history and debris flow occurrence process of Mt Fuji

富士山火山历史与泥石流发生过程

基本信息

批准号：
16510134
负责人：
YOSHIMOTO Mitsuhiro
金额：
$ 1.66万
依托单位：
Hokkaido University (2006)The University of Tokyo (2004-2005)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16510134/
关键词：
Fuji volcano Volcanic History Mud flow Boring core 土石流火山帯形成史

项目摘要

Mt. Fuji is a composite stratovolcano consisting of four volcanoes; Pre-Komitake, Komitake, Ko-Fuji (Old Fuji) and Shin-Fuji (Young Fuji) volcanoes in order of decreasing age. The Aim of this study was to obtain volcanic history of Mt Fuji using the core samples drilled at northeastern flank of the volcano by ERI, Univ. of Tokyo in 2001-2003.In the drilled cores, hornblende-bearing andesite and dacite together with basalt were found as lava flows and fragments in mud flows below the Komitake volcanic rocks which contain olivine-bearing plagioclase-phyric two-pyroxene basaltic andesite (51-53 % SiO2). The volcano whose activity produced these basalt to dacite (50-70 % SiO2) was called pre-Komitake Volcano. As a thin soil layer was found just above the pre-Komitake volcanic rocks, the activity of Komitake volcano started after a short depositional hiatus following that of pre-Komitake Volcano. It ended its activity about 100 ka roughly together with that Ashitaka Volcano. Subsequently, Fuji Volcano shifted the activity center south of Komitake Volcano and huge amount of basaltic ejecta were issued.Deposits of eastern flank of Ko-Fuji volcano before 30ka composed mainly of mudflow deposit derived from scoria fall, in contrast to scoria fall deposit after 30ka.It is possible that those conversion of deposit was caused by existence of summit glacier associated with climate change.

富士山是由四个火山组成的复合层层库can。前Komitake，Komitake，Ko-Fuji（Old Fuji）和Shin-Fuji（Young Fuji）火山的年龄降低。这项研究的目的是使用Univ的Eri在火山的东北侧面钻出富士山的火山历史。在2001年至2003年的东京。在经过钻的核心中，含有角黄色的安山岩和山矿石以及玄武岩和玄武岩一起被发现是熔岩流和泥土中的泥浆流中的泥土流中，其中包含含有橄榄石的泛岩岩酶 - 含量的两层型两甲状腺素碱基碱基碱基和esite（51-53％sio2）。活性产生这些玄武岩到dacite的火山（50-70％SiO2）称为komitake per-komitake火山。当发现稀薄的土壤层在komitake前火山岩上方，因此在短暂的沉积裂口之后开始了Komitake火山的活性。它与阿什塔卡火山大致结束了大约100 ka的活动。 Subsequently, Fuji Volcano shifted the activity center south of Komitake Volcano and huge amount of basaltic ejecta were issued.Deposits of eastern flank of Ko-Fuji volcano before 30ka composed mainly of mudflow deposit derived from scoria fall, in contrast to scoria fall deposit after 30ka.It is possible that those conversion of deposit was caused by existence of summit glacier associated with climate change.