DMT structures

Dissolution and reprecipitation of minerals are important mechanisms by which rocks can change shape (i.e. deform). The process is generally termed Diffusional Mass Transfer (DMT) - although some people refer to the dissolution part as "pressure solution". The key idea is that materials tend to dissolve when compressed (like carbon dioxide gas in a fizzy drink with the cap on) and come out of solution when the pressure is released. So the direction of maximum compression in rocks is normal to planes of maximum solution with precipitation in the direction of minimum compressive stress. You can judge this by clicking here. In fine grained rocks the surfaces of dissolution are commonly wavy. These features are called stilolites. Pressure solution is also an important way to form cleavage. There are different types of reprecipitation sites.

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