Roughness of sandstone fracture surfaces: Profilometry and shadow length investigations J. M. Boffa, C. Allain, R. Chertcoff, J. P. Hulin, F. Plouraboué and S. Roux Eur. Phys. J. B, 7 2 (1999) 179-182 Published online: 15 January 1999 DOI: 10.1007/s100510050602