Comment on “Unveiling the Transition From Paleolake Lisan to Dead Sea Through the Analysis of Lake Paleoshorelines and Radiometric Dating of Fossil Stromatolites” by Jara‐Muñoz et el.

Geochemistry Geophysics Geosystems · 2025-03-31 · 1 citations

Abstract Jara‐Muñoz et al. report a new set of U‐Th and 14 C dates obtained from stromatolites scattered along the western slopes of the Dead Sea escarpment and use them to establish a new lake‐level curve for part of the last glacial cycle. This curve is fundamentally different from previous reconstructions (Bartov et al., 2002, 2003; Hazan et al., 2005; Lisker et al., 2009; Machlus et al., 2000; Torfstein, Goldstein, Stein, & Enzel, 2013) and is characterized by very significant vertical uncertainties, which in practice, ignore the millennial‐timescale resolution of Lake Lisan dynamics that has been widely discussed before (Bartov et al., 2003; Haase‐Schramm et al., 2004; Torfstein, Goldstein, Stein, & Enzel, 2013), with important implications for understanding regional hydroclimate regimes and linkage to global climate engines. The differences between the new and previous lake‐level reconstructions warrant a critical evaluation of the new findings. We argue that rather than strengthening and refining the existing body of observations, the new data have been used separately, resulting in a misleading record.

A Conceptual Framework for Reconstructing Atlantic Ocean Circulation through the Pleistocene from a Nd isotope perspective

2025-01-01

Paleoclimate Evidence of Significant Eastern Mediterranean Aridity During Interglacial Periods: Implications for the Projected Drying Trend

2025-03-14

Extended salt deposits, indicative of pronounced aridity, are preserved in a 220,000-year sediment core from the Dead Sea in the eastern Mediterranean Levant. These arid intervals occur in the warm interglacial periods of Marine Isotope Stages (MIS) 7, 5, and in the Holocene, and coincide with maxima in the Northern Hemisphere fall precession cycle. Similar salt layers are also present during the current and penultimate deglaciations. In insolation-driven climate model simulations, the North Atlantic latitudinal surface temperature gradient intensifies in the subsequent winter when boreal fall precession reaches a maximum. A lag that is due to the inherent delay in the upper ocean response. The enhanced surface temperature gradient leads to a shift the North Atlantic eddy-driven jet stream poleward, a decrease in polar sea-level pressure and an increase subtropical sea-level pressure. A weakening in the Mediterranean winter storm track occurs and a reduction in the rainfall over the Basin. Abrupt subpolar cooling events during recent and penultimate deglaciations—driven by ice sheet melt—similarly amplify the North Atlantic latitudinal surface temperature gradient, eliciting a comparable atmospheric response and similar rainfall reductions in the eastern Mediterranean. The late Quaternary palaeohydrology of the Dead Sea thus highlights an important North Atlantic ocean-atmosphere interaction that drives eastern Mediterranean droughts. A similar link exists between the changes in the North Atlantic Basin and the eastern Mediterranean rainfall trend in recent history and helps understand CMIP6 inter-model differences in their projected eastern Mediterranean drying.

The Dead Sea ICDP drilling project: Window into the hydroclimate and seismic history of the East Mediterranean-Levant during the past 220 kyr

Abstracts with programs - Geological Society of America · 2025-01-01

Lake KINneret Drilling (KIND): reconstructing Pliocene-Quaternary hydroclimate and seismic history of the Levant

Abstracts with programs - Geological Society of America · 2025-01-01

Last Interglacial sea level derived from U-series dated fossil corals of the Turks and Caicos Islands

2024-03-08

The timing, magnitude, and evolution of sea-level change during the Last Interglacial period (Marine Isotope Stage (MIS) 5e) are subjects of ongoing debate. Previous estimates of global mean sea level (GMSL) generally converged on values of 5 to 10 meters above present levels, with one or more oscillations of up to several meters. However, more recent studies suggest considerably lower GMSL that peaked below 5 meters. Ancient coral reefs play a pivotal role in providing reliable constraints on MIS 5e sea level because they are often well preserved in the fossil record and can yield precise ages through U-series dating. Here we present a new series of high-precision U-series ages combined with detailed stratigraphic analysis and accurateelevation measurements of emergent in-situ fossil corals from Turks and Caicos Islands. We sampled well-preserved MIS 5e corals outcropping along the coastlines of North Caicos, Middle Caicos, West Caicos, and Providenciales islands. We identified corals from several paleo-habitats, including platform edge reefs and both isolated corals and patch reefs from the paleo-lagoon. The dominant coral species include Orbicella annularis, Pseudodiploria, Acropora palmata, Acropora cervicornis, and Porites porites. Many fossil corals show evidence of post-depositional alteration of their primary geochemistry. Their utility is therefore limited by their preservation. To identify unaltered corals and maximize the likelihood of closed to near-closed system behavior of our samples, we apply rigorous threshold criteria that screen samples by their mineralogy, U concentration, δ234Uinitial, and amount of detrital component. We further correct the ages for diagenetic disturbance of the U-Th isotope ratios. These results allow us to provide new sea-level constraints during MIS-5e and to assess the amount of ice melt during this period of pronounced warming.  

Suspended particulate matter influence on dissolved Nd concentration and isotopic composition along GEOTRACES section GP16

Earth and Planetary Science Letters · 2024-04-18 · 11 citations

Patagonian dust, Agulhas Current, and Antarctic ice-rafted debris contributions to the South Atlantic Ocean over the past 150,000 years

Proceedings of the National Academy of Sciences · 2024-07-23 · 5 citations

Disentangling inputs of aeolian dust, ice-rafted debris (IRD), and eroded continental detritus delivered by ocean currents to marine sediments provide important insights into Earth System processes and climate. This study uses Sr-Nd-Pb isotope ratios of the continent-derived (lithogenic) fraction in deep-sea core TN057-6 from the subantarctic Southern Ocean southwest of Africa over the past 150,000 y to identify source regions and quantify their relative contributions and fluxes utilizing a mixing model set in a Bayesian framework. The data are compared with proxies from parallel core Ocean Drilling Program Site 1090 and newly presented data from potential South America aeolian dust source areas (PSAs), allowing for an integrated investigation into atmospheric, oceanic, and cryospheric dynamics. PSA inputs varied on glacial/interglacial timescales, with southern South American sources dominating up to 88% of the lithogenic fraction (mainly Patagonia, which provided up to 68%) during cold periods, while southern African sources were more important during interglacials. During the warmer Marine Isotope Stage (MIS) 3 of the last glacial period, lithogenic fluxes were twice that of colder MIS2 and MIS4 at times, and showed unique isotope ratios best explained by Antarctic-derived IRD, likely from the Weddell Sea. The IRD intrusions contributed up to 41% at times and followed Antarctic millennial warming events that raised temperatures, causing instability of icesheet margins. High IRD was synchronous with increased bioavailable iron, nutrient utilization, high biological productivity, and decreased atmospheric CO 2 . Overall, TN057-6 sediments record systematic Southern Hemisphere climate shifts and cryospheric changes that impacted biogeochemical cycling on both glacial/interglacial and subglacial timescales.

THE LONG-TERM UPLIFT HISTORY OF BARBADOS: IMPLICATIONS FOR COASTAL COMMUNITIES AND SEA LEVEL RECONSTRUCTIONS

Abstracts with programs - Geological Society of America · 2024-01-01

SR-ND-PB RADIOGENIC ISOTOPE SIGNATURES OF PLEISTOCENE TILLS AND MIOCENE SIRIUS GROUP SEDIMENTS FROM ANTARCTICA: IMPLICATIONS FOR ICE SHEET HISTORY

Abstracts with programs - Geological Society of America · 2024-01-01