权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Japan-France cooperative study of mantle plumes by seismic observation and rock sampling on Polynesian seafloor

日法合作研究波利尼西亚海底地幔柱地震观测和岩石采样

基本信息

批准号：
16253002
负责人：
FUKAO Yoshio
金额：
$ 23.88万
依托单位：
Independent Administrative Institution, Japan Agency for Marine-Earth Science and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
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

项目摘要

We deployed 10 broadband ocean bottom seismographs to improve seismic resolution for mantle structure beneath the Polynesian region to obtain detailed structure of mantle plumes. We made a sampling survey of volcanic rocks with the submersible "SHINKAI-6500" of JAMSTEC. The obtained results are as follows.1. We determined the upper mantle S-velocity model beneath French Polynesia down to 200 km. Slow velocity anomalies were found beneath all the hot spots, while their maximum depths are different beneath different hot spots. Beneath the Society and McDonald hot spots, slow anomalies extend down at least to 200 km.2. Thickness of the mantle transition zone was determined by a receiver function method. We detected a thin transition zone only beneath the Society hot spot and did not find significant thickness anomalies beneath other stations, indicating that mantle plumes from the lower to upper mantle in French Polynesia are not broad but is localized beneath the Society hot spot.3. We determined P-velocity structure beneath Polynesia by travel time tomography using P-wave arrival times and differential P-wave arrival times among stations. There is a broad slow velocity anomaly at depths greater than 1000 km in the lower mantle. Slow anomalies are narrow at depths from 1000 to the bottom of the upper mantle. The upper mantle structure is relatively ill-resolved by the present data. A narrow slow anomaly in the lower mantle located beneath the Society hot spot suggests that a mantle plume is ascending from the lower mantle to the Society hot spot.4. We could obtain good rock samples with "SHINKAI-6500" on the seafloor along the Cook-Austral islands. Composition of the seafloor rock samples are distinct from those obtained on the land area of the Cook-Austral islands, suggesting a magma source was changed with a growth of a hot spot volcano.

为了提高波利尼西亚地区地幔结构的地震分辨率，我们部署了10台宽带海底地震仪，以获得地幔柱的详细结构。利用JAMSTEC的“SHINKAI-6500”潜水器对火山岩进行了采样测量。得到的结果如下：1。我们确定了法属波利尼西亚地下200千米的上地幔s速度模型。所有热点下均存在慢速异常，但不同热点下的慢速异常最大深度不同。在社会和麦当劳热点下面，缓慢异常至少延伸到200公里以下。用接收函数法确定了地幔过渡带的厚度。我们只在社会热点下发现了一个薄的过渡带，而在其他站点下没有发现明显的厚度异常，这表明法属波利尼西亚从下地幔到上地幔的地幔柱并不宽，而是局限于社会热点下。我们利用纵波到达时间和各测点间的差分纵波到达时间，通过行时断层扫描确定了波利尼西亚地下的纵波速度结构。下地幔在深度大于1000 km处存在广泛的慢速异常。缓慢异常在1000至上地幔底部的深度很窄。根据目前的资料，上地幔结构的解析相对较差。位于社会热点下方的下地幔中一个狭窄的缓慢异常表明地幔柱正从下地幔上升到社会热点。我们可以在Cook-Austral群岛的海底使用“SHINKAI-6500”获得良好的岩石样本。海底岩石样本的组成与库克-奥斯特拉群岛陆地地区的岩石样本不同，表明岩浆来源随着热点火山的生长而改变。

项目成果

期刊论文数量（68）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Precise Re isotope ratio measurements by negative thermal ionization mass spectrometry(NTL-MS) using total evaporation technique

使用全蒸发技术通过负热电离质谱 (NTL-MS) 进行精确的铼同位素比测量

DOI：
发表时间：
2004
期刊：
Int.J.Mass Spectrom 235
影响因子：
0
作者：
Suzuki;K.
通讯作者：
K.

Noble gas systematics of submarine alkalic lavas near the Hawaiian hotspot

DOI：
10.1016/j.chemgeo.2004.08.051
发表时间：
2005-01
期刊：
Chemical Geology
影响因子：
3.9
作者：
T. Hanyu;D. Clague;I. Kaneoka;T. Dunai;G. Davies
通讯作者：
T. Hanyu;D. Clague;I. Kaneoka;T. Dunai;G. Davies

High-pressure partial melting of mafic lithologies in the mantle

DOI：
10.1093/petrology/egh057
发表时间：
2004-12-01
期刊：
JOURNAL OF PETROLOGY
影响因子：
3.9
作者：
Kogiso, T;Hirschmann, MM;Pertermann, M
通讯作者：
Pertermann, M

Mantle discontinuity depths beneath the west Philippine basin from receiver function analysis of deep-sea borehole and seafloor broadband waveforms

通过深海钻孔和海底宽带波形的接收函数分析得出西菲律宾盆地下方的地幔不连续深度

DOI：
发表时间：
2005
期刊：
Bull. Seism. Soc. Am. 95
影响因子：
0
作者：
Suetsugu;D.;M.Shinohara;E.Araki;T.Kanazawa;K.Suyehiro;T.Yamada;K.Nakahigashi;H.Shiobara;H.Sugioka;K.Kawai;Y.Fukao
通讯作者：
Y.Fukao

Hafnium isotope ratios of nine GSJ reference samples