Magma processes in the Moho Transition Zone: an insight from volcanoes off the fast-spreading ridges

莫霍面过渡带的岩浆过程：来自快速扩张的山脊火山的洞察

• 批准号: 22403004
• 负责人: UMINO SUSUMU
• 金额: $ 10.57万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2010
• 资助国家: 日本
• 起止时间: 2010-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22403004/
• 关键词: オフリッジ火山; 巨大海底溶岩流; 深海掘削; 1256深海掘削孔; オマーンオフィオライト; 複合溶岩流; 定置過程; 内成的成長; 海底溶岩流; 融合; 高速拡大海嶺; オフリッジ火山群; モホ遷移帯; 巨大溶岩流; 海洋地殻・マントル; 中央海嶺; 東太平洋海膨; 電気伝導度構造探査; 潜水艇

Off-ridge large lava flows in the Oman Ophiolite and in ODP site 1256 were investigated to understand the emplacement process and the magma genesis by analyzing the bulk-rock and mineral compositions and textures. Both lava flows were extruded at low extrusion rates as compound flow lobes, which were merged into thick large lobes. Merged flow lobes thicken endogenously as subsequent lava was injected into the molten core of the lobes. Magma compositions changed during the eruptions, resulted in mixing of magmas. Associated alkali basalts showing intermediated characteristics between ocean island basalts and enriched mid-ocean ridge basalts indicate that the sources for the large lava flows are shallower than ocean island basalt magmas.

通过分析阿曼蛇绿岩和ODP 1256站点的体岩、矿物组成和结构，研究了蛇绿岩的脊外大熔岩流，了解了其侵位过程和岩浆成因。两股熔岩流均以低挤压速率挤压形成复合流瓣，并合并成较厚的大流瓣。合并的流瓣随着后续熔岩注入流瓣的熔融核心而内生变厚。岩浆成分在喷发过程中发生了变化，导致了岩浆的混合。伴生碱玄武岩表现出介于洋岛玄武岩和富洋中脊玄武岩之间的中间特征，表明大熔岩流的来源较洋岛玄武岩岩浆浅。

项目成果

Tsunami source of the 2011 Tohoku earthquake detected by an ocean-bottom magnetometer

• DOI: 10.1016/j.epsl.2013.09.015
• 发表时间: 2013-11
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: H. Ichihara;Y. Hamano;K. Baba;T. Kasaya

Emplacement mechanism of submarine large sheet flows from the Oman Ophiolite

阿曼蛇绿岩海底大片流的就位机制

• 发表时间: 2011
• 作者: Umino;S.
• 通讯作者: S.

Emplacement mechanism of off-axis large submarine lava field from the Oman Ophiolite

阿曼蛇绿岩离轴大型海底熔岩场的侵位机制

• DOI: 10.1029/2012jb009198
• 发表时间: 2012
• 期刊: J. Geophys. Res.
• 作者: Umino;S.
• 通讯作者: S.

Developing new magnetometer system for marine EM survey

开发用于海洋电磁测量的新型磁力计系统

• 发表时间: 2013
• 作者: Kasaya;T.;Ichihara. H.;Goto;T.
• 通讯作者: T.

Evolution of volcanism and magmatism during initial arc stage: constraints on the tectonic setting of the Oman Ophiolite. In Rollinson, H.R., Searle, M.P., Abbasi, I.A., Al-Lazki, A. and Al Kindi, M.H. (eds.), Tectonic Evolution of the Oman Mountains

初始弧阶段火山作用和岩浆作用的演化：对阿曼蛇绿岩构造环境的制约。

• DOI: 10.1144/sp392.9
• 发表时间: 2014
• 期刊: Geological Society, London, Special Publications
• 作者: Kusano;Y. Hayashi;M.;Adachi;Y.;Umino;S. and Miyashita;S.
• 通讯作者: S.