Early Pleistocene Paleoclimatic Record from Sonoran Desert, Arizona

Abstract

Three pollen spectra from lake sediments stratigraphically well below mid-Kansan fauna indicate plant associations for the Sonoran desert, Arizona, approximating those found now at elevations of 1500 ft and more above the desert floor. The presence of Ostrya, Betula, and Artemisia may indicate some invasion by northern species as well. A climate cooler or wetter, or both cooler and wetter, than the present climate is inferred from paleobotanical and sedimentary evidence. Correlation with the Nebraskan glacial stage is tentatively suggested.