A Note on the Timing and Nature of the Moho Geometry and Upper Mantle Structure Beneath Southern New England

New seismic imaging by Luo et al. (2022, https://doi.org/10.1029/2022GL099013) revealed two important lithosphere-scale structures beneath southern New England: a large offset of the Moho near the suture between Laurentia and accreted exotic terranes, and a remnant of west-dipping slab rooted in easternmost New England. Formation of a crustal-scale east-dipping thrust ramp that offsets the Moho near the Taconic suture, appears to have formed during the Late Paleozoic and hence highlights the potential of reactivation of pre-existing major structures. Formation of the west-dipping slab beneath New England also probably is a late feature since there is no evidence it was affected by the late Devonian to Carboniferous collapse of the orogenic Acadian plateau and associated lithospheric thinning, and neither is there any sign that it was impacted by the formation and ascent of the tholeiitic CAMP magmatism in the Late Triassic to Early Jurassic Hartford basin.