Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
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
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 …
Regional-Scale Mid-Jurassic To Late Cretaceous Unroofing From The Adirondack Mountains Through Central New England Based On Apatite Fission-Track And (U-Th)/He Thermochronology, Mary K. Roden-Tice, Steven J. Tice
Regional-Scale Mid-Jurassic To Late Cretaceous Unroofing From The Adirondack Mountains Through Central New England Based On Apatite Fission-Track And (U-Th)/He Thermochronology, Mary K. Roden-Tice, Steven J. Tice
Mary K. Roden-Tice
Apatite fission-track (AFT) ages of 178 to 70 Ma for 108 samples from the Adirondack Mountains and eastern New York State, Vermont, western Massachusetts and Connecticut, and western New Hampshire indicate that widespread unroofing occurred throughout the region during the Middle Jurassic to Late Cretaceous. Additionally, (U-Th)/He ages of 167 to 85 Ma were determined on nine of those samples and support cooling rates of 1.8°-2.2°C/m.yr. from 100° to 65°C during the Middle Jurassic to Late Cretaceous. Assuming a geothermal gradient of 25°C/km, unroofing rates for the region were estimated to be, on average, ∼0.07-0.08 km/m.yr. The AFT age discontinuities …
Early Cretaceous Normal Faulting In Southern New England: Evidence From Apatite And Zircon Fission-Track Ages, Mary K. Roden-Tice, Robert P. Wintsch
Early Cretaceous Normal Faulting In Southern New England: Evidence From Apatite And Zircon Fission-Track Ages, Mary K. Roden-Tice, Robert P. Wintsch
Mary K. Roden-Tice
New apatite and zircon fission‐track (AFT, ZFT) ages from Mesozoic sediments and adjacent crystalline rocks from southern New England reveal age gradients from Middle Jurassic to Early Cretaceous. These gradients reflect the rotation of crustal blocks after the setting of the youngest AFT ages (∼140 Ma). The AFT ages of 168–98 Ma for 32 samples of Paleozoic metamorphic rocks east and west and within the Hartford Basin of Massachusetts and Connecticut indicate that unroofing in these regions occurred from Late Jurassic through Early Cretaceous. In both the Hartford Basin and rocks from crystalline terranes east of the basin, AFT ages …
Tectonic Synthesis Of The Olympic Mountains Segment Of The Cascadia Wedge, Using 2-D Thermal And Kinetic Modeling Of Isotopic Ages, Geoffrey E. Batt, Mark T. Brandon, Kenneth A. Farley, Mary K. Roden-Tice
Tectonic Synthesis Of The Olympic Mountains Segment Of The Cascadia Wedge, Using 2-D Thermal And Kinetic Modeling Of Isotopic Ages, Geoffrey E. Batt, Mark T. Brandon, Kenneth A. Farley, Mary K. Roden-Tice
Mary K. Roden-Tice
A fully coupled two-dimensional kinematic and thermal model of a steady state accretionary wedge, constrained by an extensive data set of fission track and (U-Th)/He ages for apatite and zircon, is here used to investigate the development of the Olympic Mountains segment of the Cascadia accretionary wedge. The model has two main free parameters: , the maximum rate of erosion for a generic erosion function operating at the top of the wedge, and α, the distribution of sedimentary accretion into the wedge. The best fit values for and α and their confidence limits are determined through an iterative search of …