SCEC Project Details
| SCEC Award Number | 24021 | View PDF | |||||
| Proposal Category | Individual Research Project (Single Investigator / Institution) | ||||||
| Proposal Title | Slip Rates and the Deformation Field of the Northern Black Mountain Fault | ||||||
| Investigator(s) |
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| SCEC Milestones | A3-4, B3-3 | SCEC Groups | Geology, CEM, FARM | ||||
| Report Due Date | 03/15/2025 | Date Report Submitted | 03/15/2025 | ||||
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Project Abstract |
Studies show that at a large-scale, strain is partitioned into various styles in the Walker Lane domain of the North American–Pacific plate boundary, yet there remain knowledge gaps on how deformation is accommodated on its principal rift-bounding faults which dominate the regional extensional strain budget. More specifically, we seek to unravel the space-time evolution and kinematics of border faults and the implications for long-term on-fault damage, rheology, seismic behavior and fluid flow, and emplacement of economic mineralization. We focus on the Northern Black Mountain fault, which is the northernmost segment of Death Valley’s border fault, California. We completed multiple field seasons in the region, mapping the excellently exposed sections of the fault, where we document: 1) along-fault distribution of geological slip vectors, 2) fracture and alteration damage distribution across a well-exposed section of the fault, 3) microstructural analysis of fault rocks, 4) mapping of fault scarps on offset Quaternary alluvial fans, and 5) rock varnish sample collection on offset alluvial fans for age dating. Our results revealed a partitioning of slip across the fault, manifested as dextral oblique-normal slip on bedrock-bounding outer principal slip surface, and normal slip on an inner, basinward principal slip surface. Also, we found an asymmetric damage intensity across the fault zone, with greater fracturing and veining, and lower rebound strength in its hanging wall. Further, we developed geodynamic models constrained by our field observations, which demonstrate how long-term damage asymmetry influences fault evolution. Dating of alluvial fans is underway to constrain fault slip rates. |
| SCEC Community Models Used | Community Fault Model (CFM) |
| Usage Description | The CFM provided a previously mapped fault trace of the Black Mountain Fault that guided the field work. |
| Intellectual Merit | This project contributes to the understanding of long-term evolution of brittle damage, rheology, seismic behavior, and fluid flow properties of active plate boundary normal faults in eastern California, implicating the earthquake hazards of the region. The research activities are yielding unique insights into how both brittle and alteration damage of fault zones are relevant for understanding the long-term evolution of the bulk damage rheology of active faults in the upper crystalline crust. |
| Broader Impacts | The project supported the undergraduate thesis research of Columbia undergraduate student Lela Kornfeld, including multiple field seasons (Spring 2024 and Spring 2025) and conference poster presentation of the student’s preliminary field results. Also, the project supported field work training of a graduate student at Columbia University advised by PI Kolawole. |
| Project Participants | The individuals that worked on the project are Columbia graduate student Sydney Maguire, Columbia undergraduate students Lela Kornfeld, Fiona Madrid, Ben Goldman, and Macy Matthews, and Lamont-Doherty Researcher Tanzhuo Liu. |
| Exemplary Figure | Figure 1. Field photograph taken during the scanline data collection across an exposure of the Northern Black Mountain Fault Zone. PI Kolawole shows undergraduate students Lela Kornfeld, Fiona Madrid, and Ben Goldman a slip surface within exhumed dolomite-calcite-quartz-rich fault gouge of the principal slip zone of the fault. |
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Linked Publications
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