Geochronology and paleoenvironment of pluvial Harper Lake, Mojave Desert, California, USA

Quaternary Research
By: , and 

Links

Abstract

Accurate reconstruction of the paleo-Mojave River and pluvial lake (Harper, Manix, Cronese, and Mojave) system of southern California is critical to understanding paleoclimate and the North American polar jet stream position over the last 500 ka. Previous studies inferred a polar jet stream south of 35°N at 18 ka and at ~ 40°N at 17–14 ka. Highstand sediments of Harper Lake, the upstream-most pluvial lake along the Mojave River, have yielded uncalibrated radiocarbon ages ranging from 24,000 to > 30,000 14C yr BP. Based on geologic mapping, radiocarbon and optically stimulated luminescence dating, we infer a ~ 45–40 ka age for the Harper Lake highstand sediments. Combining the Harper Lake highstand with other Great Basin pluvial lake/spring and marine climate records, we infer that the North American polar jet stream was south of 35°N about 45–40 ka, but shifted to 40°N by ~ 35 ka. Ostracodes (Limnocythere ceriotuberosa) from Harper Lake highstand sediments are consistent with an alkaline lake environment that received seasonal inflow from the Mojave River, thus confirming the lake was fed by the Mojave River. The ~ 45–40 ka highstand at Harper Lake coincides with a shallowing interval at downstream Lake Manix.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Geochronology and paleoenvironment of pluvial Harper Lake, Mojave Desert, California, USA
Series title Quaternary Research
DOI 10.1016/j.yqres.2013.10.008
Volume 81
Issue 2
Year Published 2014
Language English
Publisher Elsevier
Contributing office(s) Crustal Geophysics and Geochemistry Science Center
Description 13 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Quaternary Research
First page 305
Last page 317
Country United States
State California
Other Geospatial Harper Lake;Mojave Desert
Google Analytic Metrics Metrics page
Additional publication details