as truncated reflectors at 11–15 km depth underlying the Purcell anticlinorium and overlying the basement reflectors. 75 km East along the profile is the exposure of the Lewis fault in the Waterton area, which directly links to the most displaced portion of the hanging wall. Measuring the distance between the footwall cutoff and the fault exposure at the Earth's surface, total movement of the Lewis thrust sheet was determined. Results showed that there was 75 km of direct movement of the thrust sheet along the Lewis fault, and an additional 40 km of transport by the formation of footwall-domain duplexes. Although this study did not take into consideration that it could be possible that the Lewis thrust sheet moved further east along the prairies and was eroded away, the data proved to be of high quality as it allowed excellent ties to be made to previous drill holes, mapped structures, measured stratigraphy, and existing geologic and seismic data. This study acted as a reinforcement to previous work and was very consistent with previous data collected. Additionally, this seismic data presented is significant in extensional terms as a direct link between reflectors on the West and East sides of the Rocky Mountain trench correlate to the same stratigraphic unit, where extension can be restored and an extensional distance of about 10 km was calculated by the difference of the pre extension and post extension. There is controversy over how the overthrust movement occurred and the effect this movement had on the surrounding geology. More specifically, attempting to determine if the thrust movement was continuous or if movement was subject to a more stick-slip style of movement remains inconclusive. However, the anomalously high vitrinite reflectance values obtained from the Lewis thrust at Marias Pass, the McConnell thrust at Mt. Yamnuska, the Coleman fault at Wintering Creek and several others indicate temperatures of 350–650 °C were generated during thrusting. Furthermore, these high vitrinite reflectance values were restricted to extremely narrow sections adjacent to and within the fault zones. This is indicative that the high temperatures were fairly short-lived. Thus, the high temperatures are interpreted to be the result of frictional heating during stick slip faulting. Evidence for the local high temperatures within the fault zone indicate that local areas of frictional stress must have existed, with the possibility of this occurring due to ramps in the fault plane where drainage of high pore