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Presence Of A Long-Term Lithospheric Thermal Anomaly: Evidence From Apatite Fission-Track Analysis In Northern New England, Mary K. Roden-Tice, David P. West Jr., Jaime K. Potter, Sarah M. Raymond, Jenny L. Winch

Mary K. Roden-Tice

Apatite fission-track (AFT) ages from 56 samples of Paleozoic and Mesozoic crystalline rocks in New Hampshire, northeastern Vermont, and western Maine range from 70 to 140 Ma and reflect widespread Early to Late Cretaceous cooling. The regional AFT age distributions determined in this study suggest that reactivation of preexisting orogen-parallel faults and the presence of a long-lived thermal anomaly in the lithospheric mantle controlled the late unroofing history of this part of the northern Appalachians. A northeast-trending zone of young, dominantly Late Cretaceous AFT ages (70-118 Ma) extends from southwestern New Hampshire through the central White Mountain region and continues …