Activities and Origin of Hotspot Volcanoes in Indian Ocean

印度洋热点火山的活动和起源

基本信息

批准号：
06041026
负责人：
KANEOKA Ichiro
金额：
$ 10.94万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06041026/
关键词：
Reunion Island Mauritius Island Rodrigues Island Hotspot Piton de la Fournaise Piton des Neiges Volcanic activity Indian Ocean 火山ピトン・ド・ラ・フルネ-ズ火山ピトン・ド・ネージュ火山火山岩超塩基性捕獲岩かんらん石斑晶

项目摘要

(1) Before we started the preliminary survey of the Reunion and Mauritius Island in 1994, we had visited the scientists of the IPGP (Institut de Physique du Globe de Paris) and got sufficient information directly on the sites of rocks which we wanted to collect and others. Further, we surveyed the Reunion Island from the air by a helicopter. Through the survey in 1994 and 1995, we could collect almost all kinds of samples which we want to get from the Reunion, Mauritius and Rodrigues Islands. They cover samples which range in space and time and include basalts with olivine phenocrysts and ultramafic nodules.(2) Three of our group surveyed the Rodrigues Island in 1995 and found that the geology in this island is different between the eastern and western parts and the center of volcanic activity seems to have moved from the west to the east. The magmas do not seem to have been originated from the ridge system.(3) Through the cooperative works with the scientists of the IPGP,as a volcanophysical study, we investigated the coda Q and found that it depends on the frequency of seismic waves. The coda Q around the Piton de la Fournaise volcano has been found to be identical with those of the island are and collisional regions. The time-sequence analysis has revealed that the rhythm of volcanic eruption for the Piton de la Fournase volcano and Mt. Fuji is controlled by a simpler system than those of Izu-Oshima and Miyake-jima volcanoes.(4) For collected samples, thin sections were prepared and petrological, mineralogical, chemical and isotope analyzes including K-Ar dating are undertaken. After we accumulate such data, we will discuss the characteristics and origin of the Reunion hotspot.

（1）在我们于1994年开始对团圆和毛里求斯岛进行初步调查之前，我们访问了IPGP的科学家（Globe du Globe de Paris），并直接在我们想要收集和其他人的岩石地点获得了足够的信息。此外，我们用直升机从空中调查了聚会岛。通过1994年和1995年的调查，我们可以收集几乎所有想要从团圆，毛里求斯和罗德里格斯群岛获得的样本。它们涵盖了空间和时间范围的样品，并包括带有橄榄石表晶和超镁铁质结节的玄武岩。（2）我们的三个小组在1995年对罗德里格斯岛进行了调查，发现该岛的地质学在东部和西部地区以及火山活动中心之间的地质有所不同。岩浆似乎不是起源于山脊系统。（3）通过与IPGP科学家的合作作品，作为一项火山物理研究，我们研究了Coda Q，发现它取决于地震波的频率。发现Piton de la fournaise火山周围的尾声与岛上和碰撞地区相同。 The time-sequence analysis has revealed that the rhythm of volcanic eruption for the Piton de la Fournase volcano and Mt. Fuji is controlled by a simpler system than those of Izu-Oshima and Miyake-jima volcanoes.(4) For collected samples, thin sections were prepared and petrological, mineralogical, chemical and isotope analyzes including K-Ar dating are undertaken.积累此类数据后，我们将讨论团圆热点的特征和起源。