Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 2013 | Supplemental Material
Journal Article Open

Hidden hotspot track beneath the eastern United States

Abstract

Hotspot tracks are thought to be the surface expressions of tectonic plates moving over upwelling mantle plumes, and are characterized by volcanic activity that is age progressive. At present, most hotspot tracks are observed on oceanic or thin continental lithosphere. For old, thick continental lithosphere, such as the eastern United States, hotspot tracks are mainly inferred from sporadic diamondiferous kimberlites putatively sourced from the deep mantle. Here we use seismic waveforms initiated by the 2011 M_w 5.6 Virginia earthquake, recorded by the seismic observation network USArray, to analyse the structure of the continental lithosphere in the eastern United States. We identify an unexpected linear seismic anomaly in the lower lithosphere that has both a reduced P-wave velocity and high attenuation, and which we interpret as a hotspot track. The anomaly extends eastwards, from Missouri to Virginia, cross-cutting the New Madrid rift system, and then bends northwards. It has no clear relationship with the surface geology, but crosses a 75-million-year-old kimberlite in Kentucky. We use geodynamical modelling to show that an upwelling thermal mantle plume that interacts with the base of continental lithosphere can produce the observed seismic anomaly. We suggest that the hotspot track could be responsible for late Mesozoic reactivation of the New Madrid rift system and seismicity of the eastern United States.

Additional Information

© 2013 Macmillan Publishers Limited. Received 24 June 2013; accepted 14 August 2013; published online 15 September 2013. We would like to thank R. Cox and B. Steinberger for suggestions and comments that made significant improvements to the manuscript. All seismic waveform data were downloaded from IRIS data management centre. This work is supported by the National Science Foundation through grant numbers EAR-0810303, EAR-0855815, CMMI-1028978, EAR-1161046, EAR-1247022 and EAR-1053064. This is contribution number 10074 of the Division of Geological and Planetary Sciences, California Institute of Technology. Author contributions: R.C. and D.V.H. designed the seismic study and conducted the seismic data analysis. W.L. and M.G. designed the geodynamic models and W.L. carried out the modelling. R.C., D.V.H., W.L. and M.G. provided the joint seismic-geodynamic interpretation and wrote the manuscript.

Attached Files

Supplemental Material - ngeo1949-s1.pdf

Files

ngeo1949-s1.pdf
Files (7.1 MB)
Name Size Download all
md5:2c345646a3cebe7e27f48726f3d62415
7.1 MB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 25, 2023