Stretching of the Central Pacific Lithosphere: En-Echelon Ridges and Crossgrain Lineations on the Superswell

几种类型的地球物理观测表明，太平洋中南部的岩石圈正在经历由北向南的广泛伸展。作为对这一假设的部分检验，首席调查员将调查从东太平洋隆起到图阿莫图群岛北缘长达2500多公里的一系列以前未知的梯形山脊。伸展假说的一个主要含义是，西太平洋的一些火山活动可能与岩石圈的张性破坏有关，而不是与大量的地幔热柱有关。调查的目标是首先确定海脊存在于尚未绘制海图的地方，并且它们是连续的。这些海脊还将被挖掘出来，用于岩石学和年代研究，并将确定这些海脊的磁性特征。

Several types of geophysical observations indicate that the lithosphere in the southcentral Pacific is undergoing diffuse north-south extension. As a partial test of this hypothesis, the Principal Investigator will survey a previously uncharted series of echelon ridges that extend for over 2500 km from the East Pacific Rise to the northern edge of the Tuamotu archipelago. A major implication of the stretching hypothesis is that some volcanic activity in the west Pacific may be related to tensional failure of the lithosphere rather than numerous mantle plumes. The goals of the survey are to first establish that the ridges exist where they have not been charted, and that they are continuous. The ridges will also be dredged for petrologic and age studies, and the magnetic signature of the ridges will be determined.