Constraining the crustal composition of the continental U.S. using seismic observables
Constraining the crustal composition of the continental U.S. using seismic observables
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使用地震观测值约束美国大陆的地壳成分
DOI：
10.1130/b36229.1
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Schulte-Pelkum, Vera
中科院分区：
文献类型：
--
作者：
Sui, Siyuan;Shen, Weisen;Mahan, Kevin;Schulte-Pelkum, Vera
地壳的组成是大陆估计中最不确定和最有争议的组成部分之一，原因是：（1）直接获取有限;（2）间接评估不一致。在这里，我们表明，通过结合高分辨率的剪切速度（Vs）模型与新测量的压缩波速度（Vp）和Vs，或Vp/Vs比，结晶地壳，3-D组成（SiO2 wt %）模型的大陆地壳与不确定性估计新测量的比率。将该模型与当地捕虏体数据进行比较，结果表明在地壳中下部具有一致性。大量SiO2含量的空间分布与主要地质区相关，包括美国西部新生代和中生代基性火山活动的足迹，并为美国大陆的组成和演变提供了新的见解。
The composition of the crust is one of the most uncertain and controversial components of continental estimates due to (1) limited direct access and (2) inconsistent indirect assessments. Here we show that by combining high-resolution shear velocity (Vs) models with newly measured with newly measured ratio of compressional wave velocity (Vp) and Vs, or Vp/Vs ratio, for the crystalline crust, a 3-D composition (SiO2wt%) model of the continental crust can be derived with uncertainty estimates. Comparing the model with local xenolith data shows consistency at mid and lower crustal depths. The spatial patterns in bulk SiO2content correlate with major geological provinces, including the footprints of Cenozoic and Mesozoic mafic volcanism in the western U.S., and offer new insight into the composition and evolution of the continental U.S.