Late Quaternary fluvial history of Santa Cruz Island, California, USA

Western North American Naturalist
By:  and 

Links

Abstract

The geologic history of fluvial systems on Santa Cruz Island (SCI) is complex, involving responses to both allogenic and autogenic forcings. During periods of low or lowering sea level, canyons on the island were eroded and sediment was transported off the island onto the exposed marine shelf. When sea level rose, streams aggraded, building a sedimentary wedge that progressed from the shelf upstream into the canyons. This cycle of erosion and aggradation in response to glacial–interglacial sea-level cycles was likely repeated numerous times during the Quaternary, although clear evidence of only the most recent cycle is present in the island’s alluvial sequences. Christy, Sauces, and Pozo Canyons contain thick packages of fine-grained sediments that were deposited as a result of the interaction between autogenic depositional processes and allogenic forcing of continuous base-level rise. Other canyons on the island either have little alluvial fill due to their steep gradients or are filled with coarse-grained, recent (likely late Holocene) alluvium that covers the older alluvial deposits. Differences in the nature and extent of the alluvial exposures on SCI relative to those on neighboring Santa Rosa Island reflect differences in the local topography, geology, and ranching histories of the 2 islands.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Late Quaternary fluvial history of Santa Cruz Island, California, USA
Series title Western North American Naturalist
DOI 10.3398/064.078.0401
Volume 78
Issue 4
Year Published 2017
Language English
Publisher Monte L. Bean Life Science Museum
Contributing office(s) Geosciences and Environmental Change Science Center
Description 19 p.
First page 511
Last page 529
Country United States
State California
Other Geospatial Santa Cruz Island