Mountain Building: regional vs local uplift in the western Transverse Ranges
Collaborators: Tony Garcia
Students: Clay Kelty, Casey Slatten, Ani Pytlewski, Eric Tutterow, Spencer Cooper
Funding: NSF Tectonics
Most mountain ranges have components of local uplift (along single structures) and more regional uplift (presumably related to deeper processes). My students and I are working to understand mountain building processes by documenting the timing and style of Quaternary deformation and uplift in the western Transverse Ranges. We are using Late Quaternary deposits and fluvial and marine terraces as markers for deformation and luminescence dating to constrain the timing of the deformation.
Wave cut platform (and a paleo- sea stack) at Wall Beach on Vandenberg Air Force Base. This is the lowest of several wave-cut platforms that have been lifted along the western coast of the Transverse Ranges. We are measuring and dating these terraces to document the spatial distribution of uplift and deformation. Ian McGregor for scale.
Dan Boyd and Clay Kelty work on an exposure of the Santa Ynez Fault. The Santa Ynez fault has been interpreted to be mainly strike-slip by many authors, but has obvious vertical offset and topographic gradients across it as well. This picture shows an exposure where two strands of the fault zone are present- one strand dips 40° south and offsets a Late-Pleistocene terrace by about 20 m. A second vertical strand exhibits lateral offset, but we have not yet established the amount of lateral displacement.
Vineyards and fluvial terraces along the lower Santa Ynez River in the uplifted Santa Rita Hills. These hills are an antiform above a blind fault (the Santa Ynez River Fault) that grew up through the lower Santa Ynez River valley. Fluvial deposits on top of these hills show about 200 m of uplift since the last glacial high-stand.
