Complex breakaway zone faulting and fanglomerate deposition, Sevier Desert Detachment (SDD), Canyon Range, UT

Conference · Thu Apr 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5023007

Otton, J K ^[1]

---

1. Geological Survey, Lakewood, CO (United States)

The breakaway zone of the SDD is exposed on the west and south sides of the Canyon Range near Delta, UT. The west side is marked by a north-south-trending, west-dipping normal fault zone where early high-angle normal faulting dropped Canyon thrust plate sedimentary rocks down against Pavant plate sedimentary rocks. Later lower angle normal faulting cut these earlier faults and juxtaposed fanglomerates of the Miocene Oak City Formation against footwall rocks. These fanglomerates dip 15[degree]--30[degree] east and contain clasts and large rock avalanches of Canyon plate rocks, clasts of Late Cretaceous-early Tertiary conglomerate that is exposed only on the eastern edge of the range, and, locally, clasts of Oligocene volcanic rocks not presently exposed in the range. On the south side of the range is an east-west-trending strike-slip fault zone that links the west Canyon Range and Scipio Pass segments of the SDD. It is characterized by early right-lateral movement and later, cross-cutting, high-angle, oblique-slip movement that dripped Oak City fanglomerates down against the older sedimentary rocks of the range. Slip vectors for the first phase of motion presently plunge 10[degree]--15[degree] E. Assuming early strike-slip movement of the south side slightly down and to the west, the range has been tilted 15[degree]--20[degree] to the east. These southerly Oak City fanglomerates contain abundant clasts of Late Cretaceous and early Tertiary sandstones that are presently exposed only on the east edge of the Scipio Pass area and in the range east of Scipio Valley. These clast-source relations suggest that The Canyon Range block extended farther east in Oak City time, but since then has been broken up by normal faults that formed Scipio Valley, a younger graben.

• OSTI ID: 5023007
• Report Number(s): CONF-9305259--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CONGLOMERATES
DEPOSITION
DEVELOPED COUNTRIES
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
NORTH AMERICA
ORIENTATION
PETROLOGY
ROCKS
SEDIMENTARY ROCKS
USA
UTAH