Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 2018 | public
Journal Article

Sycamore Knoll: A wave-planed pop-up structure in a sinistral-oblique thrust system, Southern California Continental Borderland

Abstract

At the boundary between the Western Transverse Ranges province and Inner Continental Borderland of Southern California, strain is partitioned across the sinistral-oblique Anacapa-Dume Fault system. Sycamore Knoll, a pop-up structure 20 km west of Point Dume in the hanging wall of the north-dipping Anacapa-Dume Fault, stands out as an anomalous bathymetric high along the Southern California coast. We synthesize new and existing geophysical datasets, including multibeam bathymetry/backscatter and single/multichannel seismic, to understand the morphology and tectonic implications of Sycamore Knoll. We identify a complete eustatic low-stand submerged marine-terrace package encircling Sycamore Knoll platform that corresponds to the Last Glacial Maximum (LGM). The marine-terrace deposits and wave-planed surface of Sycamore Knoll require a late Quaternary uplift rate of 0.55 (+0.5/−0.3) mm/yr relative to sea-level. By combining our uplift rate with previous estimates of basin subsidence and a revised structural model of the Anacapa-Dume Fault, we determine a maximum slip rate in latest Quaternary time of 1.50 (+0.5/−0.3) mm/yr and hence a post-LGM rate of convergence across the Anacapa-Dume Fault of 0.60 (+0.2/−0.1) mm/yr.

Additional Information

© 2018 Elsevier Ltd. Received 9 May 2017, Revised 8 January 2018, Accepted 9 March 2018, Available online 27 March 2018.

Additional details

Created:
August 21, 2023
Modified:
October 18, 2023