Title

Geometry and Kinematics of Fault Slip Transfer from the Southern Walker Lane to the Mina Deflection

Presenter Information

Rachelle Warren

Document Type

Oral Presentation

Location

SURC Ballroom C/D

Start Date

15-5-2014

End Date

15-5-2014

Keywords

Fault slip, Kinematics, Walker Lane

Abstract

The Mina deflection (MD) is structural step-over that transfers fault slip from the southern Walker Lane (WL) to the central WL by a combination of sinistral, dextral, and normal faults. Recent geologic studies in the southwestern MD provide insight into the kinematics of fault-slip transfer from the WL to the MD. The southwestern MD is a faulted volcanic field underlain by Miocene latite (~11.17 Ma), Pliocene hornblende dacite, tuffaceous sandstone, basalt flows (~3.13 to 3.43 Ma), andesite, and cinder cones, and Quaternary sedimentary deposits. Faults, which cut all but the Quaternary units, define three zones: NW-striking dextral faults in the south, NE-striking sinistral faults in the north, and the EW-striking sinistral Coaldale fault in the center. The NW-dextral and EW-sinistral Coaldale faults are mutually cross-cutting, illustrating the complex fault geometry that transfers fault slip from the dextral faults of the WL to the sinistral faults of the MD. Offset markers identified along the strike-slip faults include basalt ridge lines, faults, and unit contacts and yield a minimum dextral offset of 0.8-1.3 km and sinistral offset of 0.6 km. Combining magnitude of offset with age of offset units yields minimum dextral and sinistral slip rates of 0.2-0.4 mm/yr and 0.2 mm/yr, respectively. Published fault kinematic models predict Pliocene dextral slip rates of ~0.4-0.8 mm/yr, sinistral slip rates of ~0.1-0.2 mm/yr, and sinistral slip rates of ≥0.4mm/yr along the Coaldale faults in the River Spring area. With the exception of the Coaldale fault, the slip rates are in agreement with the models.

Poster Number

44

Faculty Mentor(s)

Lee, Jeffrey

Additional Mentoring Department

Geological Sciences

This document is currently not available here.

Share

COinS
 
May 15th, 8:30 AM May 15th, 11:00 AM

Geometry and Kinematics of Fault Slip Transfer from the Southern Walker Lane to the Mina Deflection

SURC Ballroom C/D

The Mina deflection (MD) is structural step-over that transfers fault slip from the southern Walker Lane (WL) to the central WL by a combination of sinistral, dextral, and normal faults. Recent geologic studies in the southwestern MD provide insight into the kinematics of fault-slip transfer from the WL to the MD. The southwestern MD is a faulted volcanic field underlain by Miocene latite (~11.17 Ma), Pliocene hornblende dacite, tuffaceous sandstone, basalt flows (~3.13 to 3.43 Ma), andesite, and cinder cones, and Quaternary sedimentary deposits. Faults, which cut all but the Quaternary units, define three zones: NW-striking dextral faults in the south, NE-striking sinistral faults in the north, and the EW-striking sinistral Coaldale fault in the center. The NW-dextral and EW-sinistral Coaldale faults are mutually cross-cutting, illustrating the complex fault geometry that transfers fault slip from the dextral faults of the WL to the sinistral faults of the MD. Offset markers identified along the strike-slip faults include basalt ridge lines, faults, and unit contacts and yield a minimum dextral offset of 0.8-1.3 km and sinistral offset of 0.6 km. Combining magnitude of offset with age of offset units yields minimum dextral and sinistral slip rates of 0.2-0.4 mm/yr and 0.2 mm/yr, respectively. Published fault kinematic models predict Pliocene dextral slip rates of ~0.4-0.8 mm/yr, sinistral slip rates of ~0.1-0.2 mm/yr, and sinistral slip rates of ≥0.4mm/yr along the Coaldale faults in the River Spring area. With the exception of the Coaldale fault, the slip rates are in agreement with the models.