bedding plane . (a) A planar or nearly planar bedding surface that visibly separates each successive layer of stratified rock (of the same or different lithology) from the preceding or following layer; a plane of deposition. It often marks a change in the circumstances of deposition, and may show a parting, a color difference, or both. (b) A term commonly applied to any bedding surface, even when conspicuously bent or deformed by folding. (c) A term commonly applied to a plane of discontinuity (usually the bedding plane) along which a rock tends to split or break readily. Syn: bedding [stratig]; bed plane; stratification plane; plane of stratification.