Mantle flow beneath Arabia offset from the opening Red Sea
Mantle flow beneath Arabia offset from the opening Red Sea
复制标题
阿拉伯半岛下方的地幔流从红海开口处偏移
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
C. Stein
中科院分区：
文献类型：
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作者：
Sung‐Joon Chang;M. Merino;S. van der Lee;S. Stein;C. Stein
大陆裂陷涉及到一系列鲜为人知的岩石圈伸展、火山作用和地幔流动，这些过程演变为海底扩张。我们提出了新的见解，从反演的地震走时和波形下阿拉伯和周围地区。低速度出现在红海南部和亚丁湾，与活跃的扩张相一致。然而，热物质并没有延伸到北方红海以下，而是在阿拉伯半岛下方向东偏移，显示了来自阿法尔热点的地幔流。这条通道位于3000万年前裂谷开始以来喷发的火山岩之下，表明水流与阿拉伯半岛一起移动。我们认为，在北方红海海底扩张的情况下，反映了偏移流。这种几何形状可能演变为在北方红海的扩张，阿拉伯半岛的裂谷，或两者兼而有之。这种情况既有主动裂谷作用的一面，也有被动裂谷作用的一面，表明两者都可能在聚结成海底扩张之前发生。
Continental rifting involves a poorly understood sequence of lithospheric stretching, volcanism, and mantle flow that evolves to seafloor spreading. We present new insight from inversion of seismic traveltimes and waveforms beneath Arabia and surroundings. Low velocities occur beneath the southern Red Sea and Gulf of Aden, consistent with active spreading. However, hot material extends not below the northern Red Sea, but is offset eastward beneath Arabia, showing mantle flow from the Afar hotspot. The location of this channel beneath volcanic rocks erupted since rifting began 30 million years ago indicates that flow moves with Arabia. We propose that the absence of seafloor spreading in the northern Red Sea reflects the offset flow. This geometry may evolve to spreading in the Northern Red Sea, rifting of Arabia, or both. This situation has aspects of both active and passive rifting, showing that both can occur before coalescing to seafloor spreading.