Mantle Plume Helium in Submarine Basalts from the Gal�pagos Platform
Mantle Plume Helium in Submarine Basalts from the Gal�pagos Platform
复制标题
加拉帕戈斯平台海底玄武岩中的地幔柱氦
DOI：
10.1126/science.262.5142.2023
复制
发表时间：
1993
期刊：
影响因子：
56.9
通讯作者：
J. Lupton
中科院分区：
文献类型：
--
作者：
D. Graham;D. Christie;K. Harpp;J. Lupton
加拉帕戈斯群岛海底玄武岩玻璃中的氦-3/氦-4比率高达西部和西南部大气比率的23倍。这些结果表明，在加拉帕戈斯热点存在相对未脱气的地幔柱，并将加拉帕戈斯与夏威夷、冰岛和萨摩亚一起列为已知的仅有的具有如此高氦-3/氦-4比率的地方。在加拉帕戈斯群岛的其他地方，这一比例较低，反映了由软流层携带的耗尽物质导致的羽流稀释程度的系统变化。这些空间变化揭示了地幔柱的动力学及其与附近加拉帕戈斯扩张中心的相互作用。
Helium-3/helium-4 ratios in submarine basalt glasses from the Galapagos Archipelago range up to 23 times the atmospheric ratio in the west and southwest. These results indicate the presence of a relatively undegassed mantle plume at the Gal�pagos hot spot and place Gal�pagos alongside Hawaii, Iceland, and Samoa as the only localities known to have such high helium-3/helium-4 ratios. Lower ratios across the rest of the Gal�pagos Archipelago reflect systematic variations in the degree of dilution of the plume by entrainment of depleted material from the asthenosphere. These spatial variations reveal the dynamics of the underlying mantle plume and its interaction with the nearby Gal�pagos Spreading Center.