期刊
GEOPHYSICAL JOURNAL INTERNATIONAL
卷 156, 期 3, 页码 555-564出版社
OXFORD UNIV PRESS
DOI: 10.1111/j.1365-246X.2004.02138.x
关键词
geodynamics; mantle viscosity; Rayleigh-Taylor instability; Sierra Nevada
We use the apparent change in mantle structure beneath the Sierra Nevada since ca. 10 Ma, which suggests convective removal of eclogite-rich mantle lithosphere, and scaling laws developed for Rayleigh-Taylor instability to place constraints on the average viscosity coefficient of the mantle lithosphere. By treating the lithosphere as a non-Newtonian fluid obeying power-law creep with an exponent of n = 3.5, we may compare the inferred values of viscosity coefficient with those obtained from laboratory experiments on olivine and eclogite. The values that we obtain overlap those predicted by laboratory-based flowlaws for the range of geotherms implied by heat flux measurements within the Sierra Nevada and by metamorphic geothermometry and geobarometry of xenoliths in volcanic rock erupted in the Sierra Nevada at ca. 10 Ma. Thus, this comparison offers support for laboratory-derived flow laws, and specifically for the high stress limit suggested by Evans & Goetze (1979). Conversely, this agreement shows that the high strength of cold mantle minerals does not prohibit its removal by convective instability.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据