The elemental and mineralogical variation in a self-burning coal seam from Coalspur, Alberta, is determined using instrumental neutron activation analysis (INAA) and x-ray diffraction (XRD). The elemental variation in the coal seam is related to temperatures in the various alteration zones, i.e., oxidation, combustion, or carbonization and nature of elements. Mobilization of elements is greatest for As, Br, Cl, Mo, N, S, and Sb. Some of these elements are released to the atmosphere, as evident by the presence of orthorombic sulfur crystals on the surface or in vents at the top of the burning seam or saturation of oxidation char by volatile matter (tar). V/he-wellite (Ca C2O4, H2O) is the only Ca-bearing mineral found in the cooler area of the coal seam. Decomposition of this mineral, coupled with the presence of SO2formed by reaction of organic sulfur with O2in combustion, resulted information of a relatively high gypsum content in the combustion zone.