Evidence of repeated wildfires prior to human occupation on San Nicolas Island, California

Monographs of the Western North American Naturalist
By: , and 

Links

Abstract

Understanding how early humans on the California Channel Islands might have changed local fire regimes requires a baseline knowledge of the frequency of natural wildfires on the islands prior to human occupation. A sedimentary sequence that was recently discovered in a small canyon on San Nicolas Island contains evidence of at least 24 burn events that date to between ~37 and 25 ka (thousands of calibrated 14C years before present), well before humans entered North America. The evidence includes abundant macroscopic charcoal, blackened sediments, and discrete packages of oxidized, reddish-brown sediments that are similar in appearance to sedimentary features called “fire areas” on Santa Rosa Island and elsewhere. Massive fine-grained sediments that contain the burn evidence are interpreted as sheetwash deposits and are interbedded with coarse-grained, clast-supported alluvial sediments and matrix supported sands, pebbles, and cobbles that represent localized debris flows. These sedimentary sequences suggest that the catchment area above our study site underwent multiple cycles of relative quiescence that were interrupted by fire and followed by slope instability and mass wasting events. Our 14C-based chronology dates these cycles to well before the arrival of humans on the Channel Islands and shows that natural wildfires occurred here, at a minimum, every 300–500 years prior to human occupation.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Evidence of repeated wildfires prior to human occupation on San Nicolas Island, California
Series title Monographs of the Western North American Naturalist
Volume 7
Year Published 2014
Language English
Publisher Brigham Young University Press
Publisher location Provo, UT
Contributing office(s) Geosciences and Environmental Change Science Center
Description 13 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Monographs of the Western North American Naturalist
First page 35
Last page 47
Country United States
State California
Other Geospatial Channel Islands;San Nicolas Island
Google Analytic Metrics Metrics page
Additional metadata about this publication, not found in other parts of the page is in this table