Department Seminar: Dr. Ben van der Pluijm

Thursday, March 21, 2019 2:00 pm - 3:00 pm EDT (GMT -04:00)

Stock image of rocks, water and fish.

Clays, Faults and Orogeny

Dr. Ben van der Pluijm
Department of Earth and Environmental Sciences, University of Michigan 

Newly-formed, illitic clays are common in foreland fold-thrust belts, and the ages of fault-zone mineralization allow first-order constraints on the timing of regional deformation, fault weakening and fluid pathways. We briefly discuss our method of authigenic clay characterization and analysis, and focus on Ar-encapsulation dating.

Application to foreland fold-thrust belts in the Canadian and US Rockies shows multiple cycles (“pulses”) of orogenic wedge formation, each lasting 4-8 my, separated by longer periods of tectonic quiescence (“stick-slip orogeny”). Fault ages in the eastern Pyrenees, in contrast, preserve progressive faulting over ~20 my, with a much smaller strain rate. Variations in foreland orogenic wedges reflect tectonic setting and deformation style. 

FREE ADMISSION ~ REFRESHMENTS