Cenozoic tectonics of western North America controlled by evolving width of farallon slab

Wouter Schellart, David Stegman, Rebecca Farrington, Justin Freeman, Louis-Noel Moresi

Research output: Contribution to journalArticleResearchpeer-review

63 Citations (Scopus)

Abstract

Abstract: Subduction of oceanic lithosphere occurs through two modes: subducting plate motion and trench migration. Using a global subduction zone data set and three-dimensional numerical subduction models, we show that slab width (W) controls these modes and the partitioning of subduction between them. Subducting plate velocity scales with W-2/3, whereas trench velocity scales with 1/W. These findings explain the Cenozoic slowdown of the Farallon plate and the decrease in subduction partitioning by its decreasing slab width. The change from Sevier-Laramide orogenesis to Basin and Range extension in North America is also explained by slab width; shortening occurred during wide-slab subduction and overriding-plate-driven trench retreat, whereas extension occurred during intermediate to narrow-slab subduction and slab-driven trench retreat.
Original languageEnglish
Pages (from-to)316 - 319
Number of pages4
JournalScience
Volume329
Issue number5989
DOIs
Publication statusPublished - 2010

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