His research focusses on continental deformation, particularly normal faulting and crustal extension processes. He and his colleagues and students work to solve fundamental problems in structure and tectonics by employing a wide variety of techniques, including but not limited to: paleomagnetic analysis, isotopic dating (especially Ar/Ar), seismic reflection interpretation, thinsection microscopy, microprobe analysis and mechanical and thermal modeling. Some of recent research topics include: fault growth, continental hotspots and their thermal/mechanical effect on faulting (the subject of this lecture), the paradox of normal faulting, and fault zone studies in the brittle crust. More information on these projects can be found on Mark's Research webpage.