Thermal effects and timing of thrusting in the Moine Thrust zone

Abstract
Illite crystallinity studies in the foreland to the Moine thrust belt show a widespread heating event which is interpreted as a thermal response to thrust sheet emplacement. Temperatures reached ~275°C approximately 24 Ma after the main thrusting events. Based on the relationships between syn-thrusting intrusions and the thrust planes, combined with radiometric dates from the Moine sheet, it is argued that movement on the Moine thrust started between 440 and 430 Ma ago. Contractional slip in the Moine thrust belt ceased at about 425 Ma ago and it is proposed that illite metamorphism attained temperatures of ~275° C at about 408 Ma ago.