52 Combining Geology and Geophysics in the Appalachians

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

CORRELATION OF THREE-DIMENSIONAL VARIATIONS OF SEISMIC MOHO WITH TECTONIC TERRANES IN THE NORTHERN APPALACHIAN MOUNTAINS

Paper number: 52-5
Program: Theme Sessions
Time: 9:05 AM – 9:25 AM

Authors

Abstract

Teleseismic P-wave receiver functions are calculated to image the Moho variations in the northern Appalachian Mountains in order to explore its linkage with the geologically-defined surface terranes. Waveforms from 1995-2016 are analyzed for a total of ~200 broadband seismic stations. Consistent P-to-S phases converted at the Moho can be clearly observed. The phase arrival time shows a ribbon-shaped distribution pattern, which increases from the coastal plain northwestward to the Appalachian and Laurentian Plateaus. A distinct “sub-rectangular basin” anomaly of the Moho is observed in northern New Hamphire and western Maine. The Moho variation is roughly correlated with the Bouguer gravity anomaly and the NE-SW trending terrane boundaries. The spatial offset observed between the surface terrane boundaries and underlying Moho variations provides tight geophysical constraints on the three-dimentional distribution of accreted terranes within the crust, which significantly contribute to our understanding of the tectonic history in the northern Appalachian Mountains.

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

doi: 10.1130/abs/2018NE-310569

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