Paleoproduction and environmental change at Mono Lake (eastern Sierra Nevada) during the Pleistocene-Holocene transition

TitlePaleoproduction and environmental change at Mono Lake (eastern Sierra Nevada) during the Pleistocene-Holocene transition
Publication TypeJournal Article
Year of Publication2020
AuthorsHodelka BN, McGlue MM, Zimmerman S, Ali G, Tunno I
JournalPaleogeography Paleoclimatology Paleoecology
Date Published04/2020

The late Quaternary limnological history of Mono Lake (similar to 16.6-4.3 cal kyr BP), a hydrologically closed basin in the eastern Sierra Nevada (California), is inferred based on a multi-indicator analysis of a long (similar to 10.8 m) composite sediment core constructed from overlapping deepwater piston cores. The composite core, dated by C-14 and tephra correlation, shows variations in sedimentology, magnetic susceptibility, elemental geochemistry and stable isotopes through time, consistent with changes in aquatic productivity, hydroclimate, and volcanism. In the late Pleistocene, deepwater stratigraphy was influenced by high-amplitude water-level changes and runoff from a glaciated watershed. In contrast, Mono Lake's elevation was lower in the Early to Middle Holocene; lowamplitude water-level changes, wave reworking of the shoreline, and water-column stratification were important controls on facies during that time. The data suggest that the chief controls on organic facies development in Mono Lake - productivity, preservation, and dilution dynamics - are sensitive to climate changes that influence lake-level elevation, water chemistry, and the position of deltas. The study shows that deepwater sediments from certain locales in Mono Lake are well-preserved, continuous, and can be reliably dated with C-14 applied to terrestrial materials. When paired with precisely dated paleoshoreline data, these sediments provide a high-resolution archive of deglacial and Holocene environmental information for the eastern Sierra Nevada.