(Begin page 1873)

SCHIEFELBEIN, ILSA M. , University of Nevada Las Vegas, Geoscience, Las Vegas, NV

ABSTRACT: Fault Segmentation, Linkage, and Earthquake Hazards Along the Sevier Fault, Southwestern Utah

Segmented, long (10s to 100s of km) normal faults are common structures in extensional terranes. A better understanding of fault segmentation and how strain is passed from one fault to another on a small scale may permit a better understanding of the geometry and kinematics of segmented, long normal faults. The area from the Basin and Range province to the Colorado Plateau contains numerous segmented, long normal faults, but segment boundaries and linkage are not completely understood.

The goal of this study is to answer four questions about normal faulting processes, especially segmentation and linkage issues and Cenozoic extensional tectonics in the High Plateaus subprovince using as an example, the Sevier fault. Is the Sevier fault actively linking and forming segment boundaries? What are the geometry and kinematics of segmented, long normal faults? What are the timing constraints on movement along the Sevier fault? What are the earthquake and related hazards for the communities along the Sevier fault? The Sevier fault is a documented Quaternary fault, but may also have Holocene Movement.

Segment boundaries have not been mapped or defined for the Sevier fault. Once segment boundaries are defined, the geometry, kinematics, timing constraints, and linkage processes can be analyzed. Earthquake and related hazards for the communities along the Sevier fault then can be assessed.

The excellent exposure of the Sevier fault provides an exceptional opportunity to study the extensional fault geometry and kinematics. This study will increase our knowledge of the geometry and kinematics of segmented, long normal faults.

AAPG Search and Discovery Article #90909©2000 AAPG Foundation Grants-in-Aid