Sedimentary Response of Large Lakes to Climate Change: Direct Measurement Using High-Precision 40-Argon/39-Argon Geochronology

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

This award provides support for a study of the numerous tuff layers interbedded in the Early to Middle Green River Formation, which offer an opportunity to establish the most precise terrestrial geochronologic record of climate change available for any pre-Quaternary deposit. These sediments have been interpreted to reflect climate fluctuations ranging from annual varves, to 21,000 yr and 100,000 yr astronomical cycles, to longer-term climate changes. In the absence of precise temporal control, however, these inferences have yet to be verified. The project is a cross-disciplinary investigation of the sedimentology, stratigraphy, and precise 40Ar/39Ar radioisotope chronology of the Wilkins Peak and Laney Members of the Green River Formation, aimed at documenting rates of sediment accumulation and the absolute timing of expansions of Lake Gosiute.