The role of major right-lateral displacement throughout the North American Cordillera has been debated for 50 years. During the time period ~110-40 Ma, paleomagnetic data has consistently suggested thousands of kilometers of northward displacement, while geological studies of fault movement indicate only hundreds. This discrepancy is unavoidable because faults tend to be on the margins of terranes, resulting in few unequivocal offset markers. Wrapped up in this debate is also the subduction polarity of now accreted terranes and the western margin of North America through time, and the past size of the ocean basins that separated them. New types of data and analyses – including detrital zircon geochronology, mantle tomography, numerical modeling of plate motion, kinematics and timing of shear zone, etc. – have provided new insights into this plate boundary. The objective of this Penrose Conference is to bring together a diverse community of open-minded scholars to discuss what is agreed upon based on older and more recent data sets, determine where future work is needed, and also to work collaboratively to evaluate how all the data sets can be reconciled into a coherent model for an obliquely convergent plate boundary during the Late Jurassic to Eocene.
All pertinent information for the conference can be found on this site. Questions can be directed to: basil@geology.wisc.edu. Thanks, and we hope to see you in Idaho!