New England hotspot

The conventional opinion is that volcanic activity associated with the hotspot results from movement of the North American Plate over a fixed mantle plume.

[7] The lack of an obvious hotspot track west of Montreal has previously been ascribed to failure of the plume to penetrate the Canadian Shield, a lack of recognizable intrusions due to erosion, or strengthening of the plume when it approached the Monteregian Hills,[1][8] but more recent research has found kimberlite fields in Ontario and New York dated between 180 and 134 Ma and at Rankin Inlet to the northwest of Hudson Bay dated between 214-192 Ma which may represent an older, continental extension of the hotspot track.

[9] Some evidence, such the lack of an initial flood basalt and age progression along the New England-Quebec volcanic province, is not what is expected for a plume origin, and the case has been made that a shallow, tectonic mechanism is more plausible.

[12][13] The more recent seamounts are thought to mark discrete episodes of volcanic activity along different lines or segments of the same structural trend rather than movement of the plate over a fixed mantle plume.

[10][11] The timing of volcanic activity which coincides with major reorganisations of plate boundaries,[12][13] as well as geochemical analysis of the Monteregian plutons which indicates a lithospheric mantle source,[14] support this interpretation.