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A foliation that forms in sedimentary rocks that have been subjected to tectonic differential stress under sub-greenschist facies metamorphic conditions. It is defined by an array of sub parallel fabric elements, called cleavage domains, in which the original rock fabric and composition have been markedly changed by the process of pressure solution.The domains are separated from one another by intervals, called microlithons, in which the original rock is preserved. A spaced disjunctive cleavage is ormed by directed compressive stress that results in pressure solution in which ions diffuse away from sites of 

 dissolution through a fluid film along grain boundaries. Clays with low solubility start to concentrate in the solution zone. As shortening and pressure solution occur, the zone of clays evolves into a zone of incipient cleavage. Grains are preferentially dissolved perpendicular to sigma1 and clay flakes are rotating normal to sigma1. Ultimately a clearly defined cleavage domain is visible with containing few soluble minerals.

Spacing of Cleavage Domains: Depends on the initial clay content and the strainHigher the clay content the closer the cleavage domains. Higher the differential stress, the greater the rate of solution. Classification of Disjunctive Cleavage:

Sutured domains

Planar domains

Wavy domains

Anastomosing wavy domains

Sutured Domains occur when the clay content of the host rock is low, resulting in irregular to pitted domain surfaces.

Planar, Wavy, or Anastomosing Domains

Nonsutured domains can have either straight or wavy boundaries. If wavy boundaries are closely spaced, the domains may merge and bifurcate to form anastomosing domains.