The abundance of dawsonite in an exploration well in the Green River Formation oil shale has been characterized by well logging, FTIR, DSC, and wet chemistry. The four methods agree qualitatively but not quantitatively. Thermal analysis was then used to characterize changes in the dawsonite decomposition endotherm as a function of pressure. The peak temperature of the endotherm increased with pressure and the size decreased with pressure. The total endotherm at high temperature that includes dolomite and calcite reactions decreased with increased pressure, presumably due to formation of more stable silicates. (c) 2014 Elsevier Ltd. All rights reserved.