Geometry and Kinematics of Fault Slip Transfer from the Southern Walker Lane to the Mina Deflection
Document Type
Oral Presentation
Campus where you would like to present
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.
Recommended Citation
Warren, Rachelle, "Geometry and Kinematics of Fault Slip Transfer from the Southern Walker Lane to the Mina Deflection" (2014). Symposium Of University Research and Creative Expression (SOURCE). 57.
https://digitalcommons.cwu.edu/source/2014/posters/57
Poster Number
44
Additional Mentoring Department
Geological Sciences
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.
Faculty Mentor(s)
Lee, Jeffrey