121 Caves and Karst Through Space and Time: Biogeochemistry, Climate, and Astrobiology

We welcome submissions on the biogeochemistry, astrobiology, and historical records in of caves and karst features.

Monday, 20 October 2025
1:30 PM - 5:30 PM
HBGCC, 211

Controls on the southwest USA hydroclimate over the last six glacial-interglacial cycles

Paper number: 121-14
Program: Technical Sessions
Time: 5:05 PM – 5:25 PM

Authors

Abstract

The Great Basin in the southwest United States experienced major hydroclimate shifts throughout the Quaternary. Understanding the drivers behind these past changes has become increasingly important in improving future climate projections. Here, we present an absolute-dated δ18O and δ13C record from Devils Hole cave 2 (southern Nevada) that reveals climate and environmental changes in the southern Great Basin over the last 580,000 years. Water isotope-enabled Earth system simulations and phasing analysis show that temperature-related mechanisms are a primary driver of δ18O variability at orbital timescales, with additional drivers stemming from processes linked to North American ice volume. Vegetation density in the highlands of southwest Nevada is primarily forced by Northern Hemisphere summer seasonality. A rapid decline in vegetation density occurs during warm interglacial periods when local groundwater recharge reaches <50% greater than today. In total, the Devils Hole 2 δ18O and δ13C records shed new light on the relationship between temperature, moisture balance, and vegetation over the last six glacial-interglacial cycles.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-413412

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