Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study

9 pages, 3 figures, 2 tables, appendices

Detalhes bibliográficos
Autores: Evans, Rob L., Benoit, Margaret H., Long, Maureen D., Elsenbeck, James, Ford, Heather A., Zhu, Jasmine, García, Xavier
Formato: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2019
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/189845
Acesso em linha:http://hdl.handle.net/10261/189845
Access Level:acceso abierto
Palavra-chave:Magnetotellurics
Lithosphere
Receiver function
Seismic
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spelling Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric studyEvans, Rob L.Benoit, Margaret H.Long, Maureen D.Elsenbeck, JamesFord, Heather A.Zhu, JasmineGarcía, XavierMagnetotelluricsLithosphereReceiver functionSeismic9 pages, 3 figures, 2 tables, appendicesA joint analysis of magnetotelluric and Sp receiver function data, collected along a profile across the central Appalachians, highlights variations in regional lithospheric structure. While the interpretation of each data set by itself is non-unique, we identify three distinct features that are consistent with both the resistivity model and the receiver function image: 1) thin lithosphere beneath the Appalachian Mountains, 2) somewhat thicker lithosphere to the east of the mountains beneath the Coastal Plain, and 3) a lithosphere-asthenosphere boundary that deepens to the west of the mountains. In some regions, the correspondence between seismic velocity discontinuities and resistivity mark the base of the lithosphere, while in other locations we see seismic discontinuities that are contained within the lithosphere. At the western end of our profile a transition from highly resistive lithosphere to more conductive mantle represents the transition across the Grenville front. The thickness of lithosphere beneath the Grenville terrain is ∼140 km. Lithosphere at the eastern end of the profile has a thickness that is not well constrained by our coverage, but is at least 110 km thick. This lithosphere can be associated with a broader region of high resistivity material seen to extend further south. Directly beneath the Appalachian Mountains, lithospheric thickness is inferred to be as thin as ∼80 km, based on observations of elevated mantle conductivities and a westward-dipping seismic converter. Electrical conductivities in the uppermost asthenospheric mantle are sufficiently high (>0.1 S/m) to require the presence of a small volume of partial melt. The location of these elevated conductivities is close (offset ∼50 km to the west) to Eocene volcanic outcrops in and around Harrisonburg, VA. Our observations speak to mechanisms of intraplate volcanism where there is no divergent or convergent plate motion to trigger mantle upwelling or obvious fluid release, either of which can facilitate melting. Instead, we suggest that small scale mantle convection related either to pre-existing lithospheric thickness variations, or to lithospheric loss through delamination, coupled with relative plate motion with respect to the underlying asthenosphere, can trigger small amounts of melting. This melt migrates upslope, along the base of the lithosphere, potentially thermally eroding the lithosphere resulting in further thinningThe facilities of the IRIS Consortium are supported by the National Science Foundation under Cooperative Agreement EAR-1261681 and the DOE National Nuclear Security Administration. Seismic data acquisition and analysis was supported by NSF grant EAR-1251515 to Yale University and grant EAR-1251329 to the College of New Jersey. MT data were collected under NSF grant EAR-1460257 to WHOI, using instruments provided by the EarthScope program and maintained by Oregon State UniversityPeer ReviewedElsevierYale UniversityNational Science Foundation (US)Oregon State UniversityNational Nuclear Security Administration (US)Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]2019201920192019info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Preprintinfo:eu-repo/semantics/submittedVersionhttp://hdl.handle.net/10261/189845reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttps://doi.org/10.1016/j.epsl.2019.04.046Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/1898452026-05-22T06:33:51Z
dc.title.none.fl_str_mv Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study
title Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study
spellingShingle Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study
Evans, Rob L.
Magnetotellurics
Lithosphere
Receiver function
Seismic
title_short Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study
title_full Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study
title_fullStr Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study
title_full_unstemmed Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study
title_sort Thin lithosphere beneath the central Appalachian Mountains: A combined seismic and magnetotelluric study
dc.creator.none.fl_str_mv Evans, Rob L.
Benoit, Margaret H.
Long, Maureen D.
Elsenbeck, James
Ford, Heather A.
Zhu, Jasmine
García, Xavier
author Evans, Rob L.
author_facet Evans, Rob L.
Benoit, Margaret H.
Long, Maureen D.
Elsenbeck, James
Ford, Heather A.
Zhu, Jasmine
García, Xavier
author_role author
author2 Benoit, Margaret H.
Long, Maureen D.
Elsenbeck, James
Ford, Heather A.
Zhu, Jasmine
García, Xavier
author2_role author
author
author
author
author
author
dc.contributor.none.fl_str_mv Yale University
National Science Foundation (US)
Oregon State University
National Nuclear Security Administration (US)
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Magnetotellurics
Lithosphere
Receiver function
Seismic
topic Magnetotellurics
Lithosphere
Receiver function
Seismic
description 9 pages, 3 figures, 2 tables, appendices
publishDate 2019
dc.date.none.fl_str_mv 2019
2019
2019
2019
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Preprint
info:eu-repo/semantics/submittedVersion
format article
status_str submittedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/189845
url http://hdl.handle.net/10261/189845
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv https://doi.org/10.1016/j.epsl.2019.04.046
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,812429

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