Asynchronous Bends in Pacific Seamount Trails: A Case for Extensional Volcanism?
Asynchronous Bends in Pacific Seamount Trails: A Case for Extensional Volcanism?
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DOI：
10.1126/science.1107260
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发表时间：
2005-02
期刊：
影响因子：
56.9
通讯作者：
A. Koppers;H. Staudigel
中科院分区：
文献类型：
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作者：
A. Koppers;H. Staudigel
吉尔伯特海岭和托克劳海隆是太平洋上唯一一个有60°急弯曲的海隆步道，类似于夏威夷-皇帝弯曲（HEB）。这两个弯曲应该与4700万年前的HEB同时存在，如果它们是由静止的热点形成的，并且假设太平洋板块运动。新的40 Ar/39 Ar年龄表明，吉尔伯特海岭和托克劳海山小径的弯曲形成的时间比HEB早得多，分别为6 700万年前和5 700万年前。这种不同步弯曲不能与固定热点范例相协调，可能表明热点运动或岩浆作用引起的短期局部岩石圈伸展。
The Gilbert Ridge and Tokelau Seamounts are the only seamount trails in the Pacific Ocean with a sharp 60° bend, similar to the Hawaii-Emperor bend (HEB). These two bends should be coeval with the 47-million-year-old HEB if they were formed by stationary hot spots, and assuming Pacific plate motion only. New 40Ar/39Ar ages indicate that the bends in the Gilbert Ridge and Tokelau seamount trail were formed much earlier than the HEB at 67 and 57 million years ago, respectively. Such asynchronous bends cannot be reconciled with the stationary hot spot paradigm, possibly suggesting hot spot motion or magmatism caused by short-term local lithospheric extension.