Abstract
An archlike zone of seismic reflectivity, interpreted as an uplifted zone of ductilely deformed middle and lower crust, is imaged below the Pinaleno Mountains core complex in southeast Arizona. The top of the reflective zone coincides with the base of an inferred mid-Tertiary detachment fault beneath the Safford basin but diverges from the detachment fault as an apparent mylonite front to form a culmination at ~1.9 s (~4 km) beneath the Pinaleno Mountains. From this culmination, the zone of reflectivity dips to the southwest below the Eagle Pass detachment fault and flattens at ~4.8 s (~13.5 km) beneath the relatively unextended upper crust of the Galiuro Mountains. The data suggest that mylonite zones form not only as the continuation of detachment faults into the brittle-ductile transition, but also along a regional zone of decouping between the middle and upper crust. -from Author
Original language | English (US) |
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Pages (from-to) | 351-354 |
Number of pages | 4 |
Journal | Geology |
Volume | 22 |
Issue number | 4 |
DOIs | |
State | Published - 1994 |
Externally published | Yes |
ASJC Scopus subject areas
- Geology