Reactive dissolution instability driven by chemical diffusion with applications to harzburgite reactive dissolution
Reactive dissolution instability driven by chemical diffusion with applications to harzburgite reactive dissolution
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化学扩散驱动的反应溶解不稳定性及其在方辉橄榄石反应溶解中的应用
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Yan Guo
中科院分区：
文献类型：
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作者：
Yan Liang;Yan Guo
用线性稳定性分析方法研究了在多组分体系中反应性溶解过程中，分离岩石A和岩石B的矿物学上尖锐的平面溶解前缘的形态稳定性。在没有熔体流动的情况下，不稳定性的主要原因是熔体中的化学扩散。不稳定的化学扩散引起一类新的形态不稳定性，其中扰动的最大增长率对应于多孔系统的最小波长，该多孔系统是在几个晶粒尺寸的顺序上。在地质露头尺度上，分离两个岩石单元的化学扩散引起的不稳定溶解前缘将呈现扩散。在蛇绿岩中观察到的方辉橄榄岩和纯橄榄岩之间的扩散边界可能是这种溶解不稳定性的结果。当化学扩散趋于稳定时，不稳定波的波长较大，可以保持清晰的岩性边界。
The morphological stability of a mineralogically sharp and planar dissolution front separating rock A from rock B during reactive dissolution in a multicomponent system was examined using a linear stability analysis. In the absence of melt flow, the underlining cause for the instability is chemical diffusion in the melt. The destabilizing chemical diffusion gives rise to a new class of morphological instability in which the maximum growth rate of the perturbation corresponds to the minimum wavelength of the porous system that is on the order of a few grain sizes. On the geological outcrop scale a chemical diffusion induced unstable dissolution front separating two rock units would appear diffuse. The diffuse boundaries between the harzburgite and dunite observed in ophiolites may be a result of such dissolution instability. When chemical diffusion is stabilizing the wavelength of the instability is larger and sharp lithological boundary can be preserved.