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Carbon And Nitrogen Stable Isotopes In Organic Matter From Lake Chalco, Mexico: A Record Of Quaternary Hydrology And Climate Change, Kristin Slezak Pearthree

Earth and Planetary Sciences ETDs

Sediment cores from Lake Chalco, central Mexico, were analyzed to reconstruct paleoclimate in the neotropics. This study employs total organic carbon, organic carbon-organic nitrogen ratios, carbon and nitrogen stable isotope ratios of organic matter (OM), and lithology to reconstruct changes in lake level and productivity. During Marine Isotope Stage 3 (~42-29 ka) bulk OM d¹³C and d¹⁵N results suggest the lake experienced strong evaporation and high pH due to warm temperatures and moderate precipitation. Large amounts of terrestrial C3 plant matter were deposited during the Last Glacial Maximum (~22-19 ka), suggesting a swampy environment resulting from …