Continental extension is a major aspect of tectonics and it is important to understand the processes involved and to what extent older structures influence the localization, segmentation and orientations of younger faults. East-central Idaho is an ideal area to study extensional processes because of the long history of extension which dates back to Eocene time and produced a highly segmented and faulted crust. This project will map selected areas and conduct paleomagnetic studies to evaluate the extent to which the crust breaks up into discrete blocks which rotate about vertical axes. The results will be used to better understand the tectonic history of part of the western Cordillera, the mechanics and kinematics of crustal extension and the evolution of seismogenic normal fault zones.
