The late Quaternary limnological history of Mono Lake (~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 (~10.8 m) composite sediment core constructed from overlapping deepwater piston cores. The composite core, dated by 14C 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; low-amplitude 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 14C 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.
Bibliographical noteFunding Information:
This research was supported by the US NSF (Award # 1829093 ) and permitted by the Mono/Inyo National Forest . We are grateful to the staff at the National Lacustrine Core Facility for their support and curation of UWI-MONO15-1C/D. Support from S. Hemming, S. Colman, R. Niederreiter, M. Niederreiter, J. Backus, A. Conner, S. Azeem and J. Lucas was greatly appreciated. We are indebted to the Mono Lake Committee, especially B. Miller, for their assistance and enthusiasm. We thank our reviewers for their helpful comments. This is LLNL-JRNL-782377.
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