The ancient Norumbega fault system in Maine is one of the largest in eastern North America and, when active, was likely comparable in scale to the present-day San Andreas fault system in California. However, determining when portions of the Norumbega fault system were active has proven to be a challenge to geologists.

The goal of this research was to constrain the timing of latest movement along this fault system in the Casco Bay region of Maine using (U-Th)/He apatite thermochronology.