Vertical deformation of lacustrine shorelines along breached relay ramps, Catlow Valley fault, southeastern Oregon, USA
Abstract
Vertical deformation of pluvial lacustrine shorelines is attributed to slip along the Catlow Valley fault, a segmented Basin and Range style normal fault in southeastern Oregon, USA. The inner edges of shorelines are mapped along three breached relay ramps along the fault to examine the effect of fault linkage on the distribution of slip. Shoreline inner edges act as paleohorizontal datums so deviations in elevation from horizontal, outside of a 2 m error window, are taken to be indications of fault slip. The sites chosen represent a spectrum of linkage scenarios in that the throw on the linking fault compared to that on the main fault adjacent to the linking fault varies from site to site. Results show that the maturity of the linkage between segments (i.e. larger throw on the linking fault with respect to the main fault) does not control the spatial distribution of shoreline deformation. Patterns of shoreline deformation indicate that the outboard, linking, and/or smaller ramp faults have slipped since the shorelines formed. Observations indicate that displacement has not fully localized on the linking faults following complete linkage between segments.
- Publication:
-
Tectonophysics
- Pub Date:
- April 2016
- DOI:
- 10.1016/j.tecto.2016.02.015
- Bibcode:
- 2016Tectp.674...89H
- Keywords:
-
- Normal faults;
- Fault linkage;
- Shorelines;
- Basin and Range;
- Relay ramp