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Exfoliation joints or sheet joints are surface-parallel fracture systems in rock often leading to erosion of concentric slabs. == General characteristics of exfoliation joints == * Commonly follow topography. * Divide the rock into sub-planar slabs.〔 * Joint spacing increases with depth from a few centimeters near the surface to a few meters〔 * Maximum depth of observed occurrence is around 100 meters.〔〔〔 * Deeper joints have a larger radius of curvature, which tends to round the corners of the landscape as material is eroded〔〔〔〔〔 * Fracture mode is tensile * Occur in many different lithologies and climate zones, not unique to glaciated landscapes.〔 * Host rock is generally sparsely jointed, fairly isotropic, and has high compressive strength.〔〔〔 * Can have concave and convex upwards curvatures.〔〔 * Often associated with secondary compressive forms such as arching, buckling, and A-tents (buckled slabs)〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「exfoliation joint」の詳細全文を読む スポンサード リンク
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