Magma‐driven propagation of cracks
Magma‐driven propagation of cracks
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DOI：
10.1029/jb090ib01p00575
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发表时间：
1985-01
影响因子：
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通讯作者：
D. Spence;D. Turcotte
中科院分区：
文献类型：
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作者：
D. Spence;D. Turcotte
导出了充液裂纹二维扩展的相似解。该解通过应力强度因子同时考虑了裂纹内的流动问题和断裂问题。研究结果适用于岩石圈中岩脉和岩基的侵位以及岩浆的运移。我们表明，在这些应用中，裂缝的扩展受到岩浆粘度的限制；弹性介质的断裂抗力可以忽略不计。还考虑了就位过程中岩浆凝固对传播的限制。作为岩脉或岩台侵位的典型例子，我们得出结论：在15分钟的时间内，可以将黏度为102 Pa s的岩浆注入长2 km、宽0.5 m的裂缝中；断裂扩展速度约为0.5 m s−1。我们还得出结论，一个扩展的，充满液体的裂缝是岩浆通过岩石圈迁移的可行机制。
A similarity solution is derived for the two-dimensional propagation of a liquid-filled crack. This solution includes both the flow problem within the crack and the fracture problem through a stress intensity factor. The results are applied to the emplacement of dikes and sills and to the migration of magma through the lithosphere. We show that for these applications the propagation of the fracture is limited by the viscosity of the magma; the fracture resistance of the elastic medium can be neglected. Limitations on propagation due to magma solidification during emplacement are also considered. As a typical example for the emplacement of a dike or sill, we conclude that a magma with a viscosity of 102 Pa s can be injected into a crack with a length of 2 km and a width of 0.5 m in a period of 15 min; the velocity of fracture propagation is about 0.5 m s−1. We also conclude that a propagating, liquid-filled crack is a viable mechanism for the migration of magma through the lithosphere.