The Basin and Range Province as a Composite Extensional Domain

Abstract

The Basin and Range province is a composite Cenozoic taphrogen with a present configuration and internal geometry derived from superimposed multiple phases of extensional deformation driven by varied geodynamic impulses. Different components of the composite taphrogen derive from: (a) post-orogenic Late Paleocene to Middle Miocene slab rollback beneath overthickened crust of the Sevier-Laramide orogen, to induce migratory arc magmatism, tectonic denudation of Cordilleran metamorphic core complexes within associated domains of crustal extension, and belts of backarc rifting including pre-Middle Miocene phases of the Rio Grande rift; (b) Eocene transrotational tectonism that pivoted and displaced crustal elements of the Paleogene forearc in the Pacific Northwest; (c) late Early Miocene and younger crustal extension in the northwestern Basin and Range province (Numic subtraphrogen including segments in the Great Basin, Southeast Oregon Plateau, and Idaho-Montana border regions) as structural accompaniment to northward migration of the Mendocino triple junction; and (d) late Middle Miocene and younger crustal extension in the southeastern Basin and Range province (Piman subtaphrogen including the Gulf of California extensional province, interior Meseta Central province, and post-mid-Miocene Rio Grande rift) succeeding the rapid southward migration of the Rivera triple junction. A transtaphrogen bridge spanning the Mojave block, Eastern Transverse Ranges, and a broad region in southeastern California and southwestern Arizona experienced only limited post-mid-Miocene extensional deformation during evolution of the active Numic and Piman subtaphrogens lying to the northwest and southeast. The compound evolutionary history of the Basin and Range province renders moot any unitary theories for its geodynamic behavior.

Magmatismo y tectónica en la Sierra Madre Occidental y su relación con la evolución de la margen occidental de Norteamérica

“…La deformación no parece afectar al núcleo de la SMO, que constituye una especie de división geográfi ca entre lo que se ha defi nido como el Basin and Range mexicano, al este, y la Provincia Extensional del Golfo, al oeste (Henry y Aranda-Gómez, 2000). En este trabajo usamos el término Basin and Range esencialmente en sentido geográfi co, sin ningún sentido genético (ver Dickinson, 2002). En los extremos norte y sur (norte de Sonora y Chihuahua y Nayarit-Jalisco, respectivamente) estas dos provincias se funden ya que la extensión afectó toda la SMO (Figura 6).…”

“…Durante este periodo la placa Farallón todavía subduce bajo México; sin embargo, la placa del Pacífi co y Norteamérica ya han entrado en contacto más al norte, en California. La interacción entre las dos placas provoca la formación de una ventana astenosferica (slab window) frente a la zona de contacto (Atwater y Stock, 1998;Dickinson, 1997Dickinson, , 2002 donde la parte más profunda de la placa en subducción se despega de la parte más somera. Ferrari et al (2002) proponen que la ruptura en la placa puede haberse propagado hacia el sur-sureste por efecto del aumento del slab pull en la parte todavía unida de la placa en subducción, de manera similar a lo observado en otras áreas del mundo (e. g., Wortel y Spakman, 2000).…”

Chronostratigraphy of the Hottah terrane and Great Bear magmatic zone of Wopmay Orogen, Canada, and exploration of a terrane translation model

“…However, the evolving magmatic system is consistent with a rapidly rifting arc setting. Such an environment may result from a variety of subduction zone adjustments, including slab rollback, delamination, or flattening, or possibly the development of a pseudo-slab window from outboard ridge subduction (e.g., Dickinson 2002;Thorkelson et al 2011;Giba et al 2013). However, the suprasubduction zone geochemical signature of the rocks can also be attainted from a prior, rather than active, subduction-modified mantle (e.g., Bryan et al 2014).…”

The Cenozoic climatic and topographic evolution of the western North American Cordillera

“…Alternatively, mean surface elevations may decrease while the landscape evolves towards high-relief mountainous topography with increased peak elevations (England and Molnar, 1990). (2) The convective removal of mantle lithosphere along an east-west axis (Humphreys, 1995(Humphreys, , 2009aDickinson, 2002) predicts a rapid increase in surface elevation followed by down-drop both of which migrate from north to south. Moreover we would expect to see temporal and spatial relationship between crustal extension, volcanism and changes in surface elevation following the spatial pattern of removal of mantle lithosphere (Schmandt and Humphreys, 2010).…”