In this study, the thermal behavior of dawsonite, nahcolite, quartz, dolomite, albite, illite, analcime, kerogen and raw oil shale samples is discussed. Thermal Gravimetric Analysis (TGA), Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC) were used to study the thermal properties of the samples. The DSC dynamic experiments were performed in CO2 and N-2 atmospheres. The influence of purge gases on the thermal decomposition of kerogen, dawsonite and nahcolite was investigated. In the DSC experiments, the heating rate did not change the decomposition mechanism of both dawsonite and nahcolite and the Tp (the sample temperature at which the maximum deflection in the DSC curve is recorded) of dawsonite and nahcolite could be moved to higher temperatures by purging CO2.