52 Combining Geology and Geophysics in the Appalachians

Tuesday, 20 March 2018
8:00 AM - 12:00 PM
Diamond Ballroom I

SEISMIC EVIDENCE OF ASTHENOSPHERE UPWELLING DRIVING THE UPLIFT OF THE ADIRONDACK MOUNTAINS

Paper number: 52-4
Program: Theme Sessions
Time: 8:45 AM – 9:05 AM

Authors

  • Xiaotao Yang Presenting Author
    University of Massachusetts Amherst, Amherst, MA
  • Haiying Gao
    University of Massachusetts Amherst, Amherst, MA

Abstract

The origin of intracratonic uplifts, such as the Adirondack Mountains in the northeastern United States, has been mysterious. Based on thermal geochronological studies, doming of the Adirondack Mountains has been attributed to heating induced by the Great Meteor hotspot in the early Cretaceous. However, subsurface structural constraints on this hotspot-driven mechanism and its connection with mantle dynamics, which are critical for our understanding of the origin of the Adirondack Mountains as well as intraplate uplifts in general, are limited. Here we present a 3-D shear velocity model from full-wave seismic tomography, which reveals a distinct low-velocity column in the mantle lithosphere directly beneath the Adirondack Mountains. This feature is connected, at greater depths, with the previously observed large-scale low-velocity anomaly beneath most of the northern Appalachian Province. These two anomalies may reflect the asthenosphere upwelling triggered by edge-driven convections together with the Great Meteor hotspot. Based on isostatic modeling we conclude that the buoyancy from the asthenosphere upwelling beneath the Adirondack Mountains provides the primary force driving the uplift of the Adirondack Mountains. Our findings imply that mantle dynamics, such as asthenosphere upwelling, plays a significant role in uplifting cratonic interiors.

Geological Society of America Abstracts with Programs. Vol. 50, No. 2

doi: 10.1130/abs/2018NE-310496

© Copyright 2018 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.