Other Definitions
unconformity (dict)
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UnconformityAn unconformity is a gap in time in rock layers, where erosion occurs while deposition slows or stops. The rocks above an unconformity are usually younger than the rocks beneath. In an unconformity, data is lost and geologists must use other clues to discover the geologic history of that area. There are three types of unconformities: disconformity, nonconformity, and angular unconformity. Disconformity An unconformity betweeen parallel layers of sedimentary rock which represents a period of erosion. Nonconformity An unconformity between sedimentary rocks and metamorphic or igneous rock when the sedimentary rock lies above the metamorphic or igneous rock. Angular Unconformity An unconformity where horizontally parallel bands of sedimentary rock is above layers that are vertically parallel or layers that are at an angle to the horizontal layers.
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