Holocene sedimentary architecture and paleoclimate variability at Mono Lake, California

Abstract

Mono Lake occupies an internally drained basin on the eastern flank of the Sierra Nevada, and it is sensitive to climatic changes affecting precipitation in the mountains (largely delivered in the form of snowpack). Efforts to recover cores from the lake have been impeded by coarse tephra erupted from the Mono Craters, and by disruption of the lake floor due to the uplift of Paoha Island ~300 yr ago. In this study, we describe the stratigraphy of cores from three recent campaigns, in 2007, 2009, and 2010, and the extents and depths of the tephras and disturbed sediments. In the most successful of these cores, BINGO-MONO10-4A-1N (BINGO/10-4A, 2.8 m water depth), we used core stratigraphy, geochemistry, radiocarbon dates, and tephrostratigraphy to show that the core records nearly all of the Holocene in varying proportions of detrital, volcanic, and authigenic sediment. Both the South Mono tephra of ca. 1350 cal yr B.P. (calibrated years before A.D. 1950) and the 600-yr-old North Mono–Inyo tephra are present in the BINGO/10-4A core, as are several older, as-yet-unidentified tephras. Laminated muds are inferred to indicate a relatively deep lake (³10 m over the core site) during the Early Holocene, similar to many records across the region during that period. The Middle and Late Holocene units are more coarsely bedded, and coarser grain size and greater and more variable amounts of authigenic carbonate detritus in this interval are taken to suggest lower lake levels, possibly due to lower effective wetness. A very low lake level, likely related to extreme drought, is inferred to have occurred sometime between 3500 and 2100 cal yr B.P. This interval likely corresponds to the previously documented Marina Low Stand and the regional Late Holocene Dry Period. The BINGO/10-4A core does not preserve a complete record of the period encompassing the Medieval Climate Anomaly, the Little Ice Age, and the historical period, probably due to erosion because of its nearshore position.

Terrestrial ecosystem transformations in response to rapid climate change during the last deglaciation around Mono Lake, California, USA

“…1C) in 18-m water depth (Hodelka et al, 2020). Here, we present an age-depth model based on 23 accelerator mass-spectrometry radiocarbon dates, measured from plant macrofossils, charcoal, pollen purified by flow cytometry, and four tephra correlations (Hodelka et al, 2020; Tunno et al, 2021; Zimmerman et al, 2021; Table 1). Our Bacon age-depth model has been updated from the previous MONO15 age model presented by Hodelka et al (2020) by including four new radiocarbon dates conducted for this study (Table 1).…”

“…† New radiocarbon dates not presented by Hodelka et al (2020). *Dates from tephra from BINGO-MONO10-4A core were acquired via 14 C AMS dating and discussed in Hodelka et al (2020) and Zimmerman et al (2021).…”

“…† New radiocarbon dates not presented by Hodelka et al (2020). *Dates from tephra from BINGO-MONO10-4A core were acquired via 14 C AMS dating and discussed in Hodelka et al (2020) and Zimmerman et al (2021) C2 (756-652 cm), D (652-528 cm), E1 (528-456 cm), and E2 (456-376 cm) (Supplemental Figure 1). The Bacon age-depth model we present below was used to assign the zone ages in Figure 3 and Supplemental Figure 2.…”

Late Quaternary ostracode stratigraphy of Mono Lake (California, USA): evidence for benthic ecosystem sensitivity to climate change

“…Pigati and Springer (2022) concluded that the Death Valley paleowetland deposits confirmed that two distinct phases of the YD linked to changes in the Atlantic Meridional Overturning Circulation observed elsewhere also extended into the southwestern USA. Ostracodes and the sedimentology from Mono Ali (2018) and relative lake-level indicator Ca:Ti (red) data from the shallow-water BINGO10 sediment core (Zimmerman et al, 2020). The dashed line at 1945 masl indicates modern lake level.…”

“…Figure 9. (Top) Absolute paleoshoreline elevation data fromAli (2018) and relative lake-level indicator Ca:Ti (red) data from the shallow-water BINGO10 sediment core(Zimmerman et al, 2020). The dashed line at 1945 masl indicates modern lake level.…”