Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Relationship between Mesozoic and Cenozoic tectonic features in west central Arizona and adjacent southeastern California

Journal Article · · Journal of Geophysical Research; (United States)
;  [1]
  1. Arizona Geological Survey, Tucson (United States)
The Maria fold-and-thrust belt (MFTB) is a narrow belt of Mesozoic crustal shortening that is characterized by generally south vergent folds and thrusts that commonly displace Proterozoic crystalline rocks over deformed and metamorphosed Paleozoic and Mesozoic strata. The MFTB is cut by a south to southeast trending belt of mid-Tertiary extensional deformation. Extension was characterized by large displacements on low-angle normal faults, known as detachment faults, and by isostatic uplift of mylonitic midcrustal rocks now exposed in metamorphic core complexes. The geometry and style of extensional deformation change along the extensional belt and reveal the influence of the MFTB. Several extensional features are spatially coincident with the root zone of MFTB thrusts: (1) an areally extensive west-northwest trending belt of denuded Tertiary mylonitic fabrics in the Whipple and Harcuvar metamorphic core complexes, (2) a style of extension characterized by minimum extensional dismemberment of the upper plate and maximum denudation and uplift of deep-seated lower plate rocks, (3) an abrupt bend in the belt of arched, uplifted rocks below detachment faults, and (4) an abrupt bend in the trend of the breakaway zone of the detachment faults and an associated lateral ramp in the detachment fault system.
OSTI ID:
5073949
Journal Information:
Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:B1; ISSN 0148-0227; ISSN JGREA
Country of Publication:
United States
Language:
English