Dictionary:Differential compaction

{{#category_index:D|differential compaction}} Uneven settling of sediments as a result of loss of porosity. Differences in the irreversible volume change that rocks suffer when put under pressure, as by the weight of sediments deposited on top of them. Reefs, for example, are often less compactable than surrounding shales; the greater compaction of the shales thus produces a drape structure over the reef, and the amount of the vertical expression of the drape features becomes smaller gradually with height above the reef.