Crustal Thickness and Radial Anisotropy Below the North American Midcontinent
Description:
The relative stability and longevity of cratons preserve the imprints of major tectonic events on geologic timescales. Seismic observations provide information on compositional and structural variations of the cratonic lithosphere, shedding light on the dynamic evolution of craton interiors. The North American craton is an amalgamation of tectonic structures (rifts, basins, domes, and arches) formed in the Paleozoic and earlier. Here we present results from averaging eight crustal thickness models covering the North American midcontinent (the number of models at each grid is variable) and compare them with other geophysical observations, such as lithosphere thickness and shear-wave velocity model. Our crustal thickness results reveal heterogeneous crustal thickness across tectonic units, with relatively deep (about 45-55 km) Moho beneath the Williston, Illinois, and Appalachian Foreland Basins and shallower (about 35-42 km) Moho below the Forest City Basin and the central and northwestern Michigan Basin. In addition, we will build a radial anisotropy model using ambient noise cross-correlation to investigate the crustal modification associated with different structural features. We will examine the relationship among the variation of crustal, lithospheric thickness, seismic isotropic, and anisotropic velocity structures to understand the tectonic evolution of the North American midcontinent. Our study, joining with geological and geochronological constraints, will contribute to understanding the connection between regional tectonic events (relative timing and scales) and local heterogeneities and, in general, the style and scale of the tectonic evolution of cratonic interiors.
Session: Tectonics and Seismicity of Stable Continental Interiors - II
Type: Oral
Date: 5/3/2024
Presentation Time: 11:15 AM (local time)
Presenting Author: Haoyu
Student Presenter: Yes
Invited Presentation:
Authors
Haoyu Li Presenting Author Corresponding Author li4897@purdue.edu Purdue University |
Xiaotao Yang xtyang@purdue.edu Purdue University |
Brandon Herr herrb@purdue.edu Purdue University |
Lijun Liu ljliu@illinois.edu University of Illinois Urbana-Champaign |
Andrea Stevens Goddard alsg@iu.edu Indiana University |
Gary Pavlis pavlis@indiana.edu Indiana University |
Douglas Schmitt schmitt@purdue.edu Purdue University |
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Crustal Thickness and Radial Anisotropy Below the North American Midcontinent
Category
Tectonics and Seismicity of Stable Continental Interiors