The role of lower-crustal hydration in the tectonic evolution of the Colorado Plateau
The role of lower-crustal hydration in the tectonic evolution of the Colorado Plateau
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下地壳水合作用在科罗拉多高原构造演化中的作用
DOI：
10.1016/j.tecto.2017.05.025
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发表时间：
2017
期刊：
影响因子：
2.9
通讯作者：
W. Holt
中科院分区：
文献类型：
--
作者：
R. Porter;T. D. Hoisch;W. Holt
长期以来，地质学家一直在争论科罗拉多高原抬升的时间和机制，并提出了许多假说来解释每一种假说。我们使用面波层析成像来研究科罗拉多高原及周边地区的岩石圈结构，并将这些数据与热力学模拟相结合，以更好地约束较低的地壳成分、含水率和密度。我们的结果表明，现代高原海拔的15%(~290m)可以由下地壳的水化作用均衡地支撑，这降低了岩石圈的总体密度。科罗拉多高原岩石圈的水化可能是由于法拉隆板块在平板俯冲过程中脱水而发生的。随后的变暖和扩张可能进一步降低了高原边缘的地壳密度，降幅高达110千克/立方米。这可能是伸展侵入高原和高原周围地幔内发生小尺度对流的结果，可能有助于解释高原边缘的高地形。
Geologists have long debated the timing and mechanism for uplift of the Colorado Plateau with numerous hypotheses proposed to explain each. We use surface wave tomography to examine the lithospheric structure of the Colorado Plateau and surrounding regions and combine these data with thermodynamic modeling to better constrain lower crustal composition, water content, and density. Our results show that about 15% (~ 290 m) of the modern plateau elevation can be supported isostatically by hydration of the lower crust, which reduces the overall density of the lithosphere. Hydration of the Colorado Plateau lithosphere likely occurred due to dewatering of the Farallon slab during flat-slab subduction. Subsequent warming and extension have likely further reduced the density of the crust along the plateau margins by as much as 110 kg/m3. This is likely a result of extension encroaching into the plateau and small-scale convection occurring within the mantle surrounding the plateau, and may help explain the high topography on the margins of the plateau.
影响因子：
56.9
作者：
Lijun Liu;D. Hasterok
通讯作者：
Lijun Liu;D. Hasterok