A Study of the Correlation between and Chronology of Sites of human Habitation and Volcanic Ejecta in the Izu Islands

伊豆群岛人类居住地与火山喷出物的相关性及年代学研究

• 批准号: 63580199
• 负责人: SUGIHARA Shigeo
• 金额: $ 1.28万
• 依托单位: Meiji University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63580199/
• 关键词: Izu Islands; Hchijo-jima; Tephrochronology; Aira-Tanzawa-volcanic ash; Kikai-Akahoya volcanic ash; Caldera; Jomon period; Radiocarbondating; 姶良Tn火山灰; 鬼界-アカホヤ火山灰; カルデラ; 縄文時代; 放射性炭素による年代測定; 鬼界アカホヤ火山灰; カルデラの形成; 降下テフラ

Buried under the volcanic ejecta of the Izu Islands there have been discovered a great many sites and relics dating from the Jomon period and later. A study of the tephrochronology of the Izu Islands was undertaken by investigating the correlation between and chronology of these remains and the ejecta. The results may be summarized as follows.1)Following an examination of widespread tephra in the Izu Islands. the stratigraphic relationship between the ejecta and Kikai-Akahoya Volcanic ash(K-Ah) on Hachijo-Jima, Miyake-jima, et.al. was clarified, and Aira-Tanzawa volcanic ash (AT) was discovered at the Hachijo-jima.2)On the basis of its stratigraphic relationship with the sites and relies discovered in ejecta on the Izu Islands. it was ascertained that Kikai-Akahoya volcanic ash represents a maker bed for the late Initial Jomon period.3)Following an examination of the history of the formation of Higashi-yama on the basis of tephra stratigraphy, widespread tephra, earthenware types and radiocarbon dating, it was established that the caldera was formed at a time extremely close to the ejection of Aira-Tanzawa volcanic ash 21,000 to 22,000 years ago.4)The rhyolite and daite volcanic ash thought to originate from Kozu-shima. Ni-Jima, Bayonnaise Rocks will in the future serve as an important marker bed in Izu Island. Tephra fall from the Izu Islands was discovered in the Izu Peninsula and in the Boso peninsula. This should prove to be of considerable assistance in studies on tephrochronology of these regions.

在伊豆群岛的火山喷发物下埋藏着许多绳文时代及以后的遗址和遗迹。通过调查这些遗骸和喷射物之间的相关性和年代学，对伊豆群岛的年代学进行了研究。结果可概括如下：1)对伊豆群岛广泛分布的火山灰进行了检查。八丈岛、三宅岛等地喷出物与Kikai-Akahoya火山灰(K-Ah)之间的地层关系。澄清了，在八丈岛发现了姫良丹泽火山灰（AT）。2）根据其与遗址的地层关系，依赖于在伊豆群岛的喷射物中发现的。已确定Kikai-Akahoya火山灰代表了初期绳文时代晚期的造物床。3)根据火山灰地层、广泛分布的火山灰、陶器类型和放射性碳年代测定法对东山的形成历史进行了研究，确定了火山口的形成时间与姶良-丹泽火山灰的喷发时间极为接近 21,000至22,000年前。4）流纹岩和黛石火山灰被认为起源于神津岛。新岛的贝恩尼斯岩今后将成为伊豆岛的重要标志床。伊豆群岛的火山灰在伊豆半岛和房总半岛被发现。这对这些地区的年代学研究有很大帮助。