Moho temperature and mobility of lower crust in the western United States

TitleMoho temperature and mobility of lower crust in the western United States
Publication TypeJournal Article
Year of Publication2018
AuthorsSchutt D.L, Lowry A.R, Buehler J.S
JournalGeology
Volume46
Pagination219-222
Date Published2018/03
Type of ArticleArticle
ISBN Number0091-7613
Accession NumberWOS:000427129500011
Keywordscontinental lithosphere; density; Geology; mantle beneath; Olivine; seismic velocities; thickness; USArray; xenoliths
Abstract

We use measurements of mantle P-wave velocity from the Moho refracted phase, Pn, to estimate temperature within the uppermost few km of the western U.S. mantle. Relative to other approaches to modeling the deep geotherm, using Pn velocities requires few assumptions and provides a less uncertain temperature at a tightly constrained depth. Assuming a homogeneous mantle composition, Moho temperatures are lowest in an arc that extends from the High Lava Plains through western Montana and the high-plains region of Wyoming and western Kansas/Nebraska. Highest temperatures are observed under recent (<10 Ma) volcanic provinces and are consistent with melting. Estimates of lower crustal viscosity suggest that the western U.S. west of the Laramide deformation front likely has regions of mobile lower crust that decouple upper crustal and upper mantle tractions.

DOI10.1130/g39507.1
Short TitleGeology
Student Publication: 
No