From a geotechnical perspective, bedding is a discontinuity in a rock mass. Sedimentology is concerned, in part, with the origin of bedding. There is much to be gained by a melding of the two disciplines in the underground coal-mining sector. Bedding controls the strength uf rock; units in coal measures by defining beams that may or may not span openings. Voussoir beam theory can be used to explain how massive sandstone/conglomerate units can span longwall panels and what thickness of roof beam is required to span a coal mine roadway. Bedding also controls the way in which stresses are distributed about coal mine openings. By utilizing transverse isotropic elastic properties. the effect, of bedding can be readily implemented in continuum numerical codes. Geologists logging core need to discriminate between bedding as a textural element in the rock and bedding as a geotechnical discontinuity. Geotechnical engineers need to explicitly consider bedding when formulating their design models. (C) 2001 Elsevier Science B.V. All rights reserved.