...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Variations in the distribution of magma in the lower crust and at the Moho beneath the East Pacific Rise at 9°-10°N
【24h】

Variations in the distribution of magma in the lower crust and at the Moho beneath the East Pacific Rise at 9°-10°N

机译：9°-10°N东太平洋上升以下的地壳下部和莫霍面的岩浆分布变化

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Measurements of the seafloor deformation under ocean waves (compliance) reveal an asymmetric lower crustal partial melt zone (shear velocity less than 1.8 km/s) beneath the East Pacific Rise axis between 9° and 10°N. At 9°48'N, the zone is less than 8 km wide and is centered beneath the rise axis. The zone shifts west of the rise axis as the rise approaches the westward-stepping 9°N overlapping spreading center discontinuity and is anomalously wide at the northern tip of the discontinuity. The ratio of the compliance determined shear velocity to the compressional velocities (estimated by seismic tomography) suggests that the melt is well-connected in high-aspect ratio cracks rather than in isolated sills. The shear and compressional velocities indicate less than 18% melt in the lower crust on average. The compliance measurements also reveal a separate lower crustal partial melt zone 10 km east of the rise axis at 9°48'N and isolated melt bodies near the Moho beneath four of the 39 measurement sites (three on-axis and one off-axis). The offset of the central melt zone from the rise axis correlates strongly with the offset of the overlying axial melt lens and the inferred center of mantle melting, but its shape appears to be controlled by crustal processes.
机译：在海浪作用下海底变形的测量（顺应性）显示，东太平洋上升轴下方9°至10°N之间有一个不对称的下部地壳部分熔融带（剪切速度小于1.8 km / s）。在北纬9°48'时，该区域的宽度不足8公里，并位于上升轴下方。当上升接近向西移动的9°N重叠扩展中心间断时，该区域向上升轴的西侧偏移，并且在该间断的北端异常变宽。依从性确定的剪切速度与压缩速度的比值（通过地震层析成像估计）表明，熔体在高纵横比的裂缝中而不是在孤立的基台中是良好连接的。剪切速度和压缩速度表明下地壳中的熔体平均少于18％。顺应性测量还显示了上升轴以东10公里处9°48'N处的一个单独的下部地壳部分熔融带，以及在39个测量点中的四个测量点下方的Moho附近的孤立熔体（三个同轴和一个离轴） 。中心熔体区相对于上升轴的偏移与上覆轴向熔体透镜的偏移以及推断的地幔熔融中心强烈相关，但其形状似乎受地壳过程控制。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号