A multi-proxy record of volume in the Great Salt Lake over the Holocene

Continental paleoclimate records for the Holocene are essential for understanding the influence of climate modes on terrestrial settings. Terminal lakes, like the Great Salt Lake, UT (GSL) are particularly well suited for examining changes in water balance in response to large scale climate change. We present records of lipid abundance and hydrogen isotope data; hydrogen and oxygen isotope variability in brine shrimp cysts; carbonate oxygen and carbon isotopes; and variability in mineralogy from reflectance spectrometry in a core spanning 9 to 2 ka bp from the GSL. The isotopic value of lake waters are inferred from the cyst isotope records. The oxygen isotopic composition of cysts decreases slowly by about 2 ‰ from the beginning of the record (approx. 9 ka bp) to about 6 ka, and is highly variable after about 4.5 ka bp. This gradual isotopic decrease suggests increased water input into the GSL up to the Mid-Holocene and more variable inputs after. Some portion of the decrease is likely attributable to a reestablishment of equilibrium with local precipitation sources following the rapid evaporation of Lake Bonneville at the end of the Pleistocene. Carbonate oxygen and carbon isotope ratios co-vary before 5.5 ka and after 4.5 ka, and are anti-correlated between, suggesting a major restructuring of the hydrologic regime in the Mid-Holocene. Distributions of lipid and <it>n