Monteregian hotspot track: A long-lived mantle plume

The Monteregian Hills, the younger White Mountains, and the New England Seamounts constitute a well-defined hotspot track. The evolution of the plume through time is obtained from the marine track. The buoyancy flux of the plume when it made the New England Seamounts was about 2 Mg s^-1 which would make it the seventh or eighth most active plume today. The hotspot declined in activity after it made Nashville Seamount. The buoyancy flux when it made Corner Seamounts and today is less than 0.5 Mg s^-1. The changes in the flux of the marine hotspot limit how far the marine flux can be extrapolated to the west onto the continental track and what can be learned in general about vulnerability of the continental lithosphere to hotspots. The lack of an obvious track west of Montréal may be due either to failure of the plume to penetrate the Canadian Shield, to the lack of recognizable intrusions, or to strengthening of the plume when it approached Montreal.