Tectonics of Mid-Tertiary extension along a transect through west central Arizona

J. E. Spencer, Stephen Reynolds

Research output: Contribution to journalArticle

102 Citations (Scopus)

Abstract

The large-magnitude Miocene extension occurred primarily along three imbricate, northeast dipping normal faults. The structurally highest of these faults, the gentle dipping Buckskin-Rawhide detachment fault, accommodated approximately 66 km of crustal extension, whereas the two structurally lower faults accommodated a total of about 20 km extension. Most of the upper plate of the Buckskin-Rawhide detachment fault was largely undeformed by internal extension; only the thin, tapered end of the upper plate was highly extended. During extension the lower plate must have flexed to conform to the listric underside of the upper plate and to have flattened to its present subhorizontal form as it was uncovered. Grooves on the underside of the upper plate were apparently imposed on the pliable lower plate as it was denuded, forming extension-parallel folds in the lower plate. Low flexural strength characterized the lower plate during denudation, and highly mobile, low-viscosity deeper crust must have effectively decoupled the upper crust from the mantle lithosphere. -from Authors

Original languageEnglish (US)
Pages (from-to)1204-1221
Number of pages18
JournalTectonics
Volume10
Issue number6
StatePublished - 1991
Externally publishedYes

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Tectonics
Bending strength
tectonics
transect
Viscosity
detachment fault
dipping
detachment
crusts
denudation
upper crust
normal fault
flexural strength
lithosphere
viscosity
Miocene
grooves
crust
fold
mantle

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics

Cite this

Tectonics of Mid-Tertiary extension along a transect through west central Arizona. / Spencer, J. E.; Reynolds, Stephen.

In: Tectonics, Vol. 10, No. 6, 1991, p. 1204-1221.

Research output: Contribution to journalArticle

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