Clumped isotope paleotemperatures from MIS 5 soil carbonates in southern Hungary

Abstract

Quantitative paleotemperature reconstructions for the continents, including East Central Europe, over marine isotope stage 5 (MIS 5) and specifically the last interglacial (LIG, MIS 5e) are scarce and mostly based on pollen assemblages. Here we provide soil and air temperature reconstructions for the summer season of MIS 5e (5c) using carbonate clumped isotope thermometry applied to soil carbonate concretions in the Dunaszekcső loess-paleosol record, Southern Hungary. The sediments making up the S1 pedocomplex investigated represent the MIS 5 as demonstrated by bracketing K-feldspar post IR-IRSL 225/290 ages of ~63 to 164 ka. Both the absolute ages and pedogenic susceptibility (χ P) curve indicate that all the subtages of MIS 5 were found to be recorded in the sequence, and soil carbonates found >1 m depth below the paleosurface of the S1 soil provide pristine, undisturbed isotopic signals. The soil carbonate concretions likely formed during MIS 5e at a relatively shallow (20-50 cm) depth, but a later formation during MIS 5c at >50 cm depth is also plausible. Clumped isotope-based soil temperatures (ST-Δ 47sc) ranged from 16 to 20 ºC, and reconstructed summer season air temperatures (SATs) for the LIG are consistently lower than the modern values at the site by 1-5 ºC, matching surprisingly well the soil bacteria membrane lipidbased MIS 5e air temperature estimates from a nearby Serbian site. At the same time, the reconstructed SAT values do not match the 2-4 ºC positive warm season anomalies modeled for East Central Europe between LIG and present-day in paleoclimate simulations. ST uncertainties of 1-6 ºC, infiltration-driven cooling of soil temperatures, and the possibility of MIS 5c formation of the investigated carbonates may account for this proxy-model data discrepancy. Oxygen isotope compositions of summer season paleo-rainwaters for MIS 5e (5c), as reconstructed using the ST-Δ 47sc and δ 18 O sc data of soil carbonates, were found in a range of-6.7 and-6.4 ‰, matching the modern mean summer season value of-6.2±0.94 ‰ within error.

Late Pleistocene Climate and Dust Source From the Mobarakabad Loess–Paleosol Sequence, Northern Foothills of the Alborz Mountains, Northern Iran

“…Soil carbonate isotope studies of modern soils and paleosols have typically focused on samples collected from temperate or warm environments (e.g., Quade et al, 2007;Hough et al, 2014;Diaz et al, 2016;Gallagher and Sheldon, 2016;Ringham et al, 2016;Bayat et al, 2017;Dietrich et al, 2017). The carbon and oxygen isotope composition of pedogenic carbonate (δ 13 C pc and δ 18 O pc ) and land snail shell carbonate within successions of rapidly buried Quaternary soils exhibit stratigraphic trends that are interpreted to record a history of significant climate variation and provide an additional technique for investigating Quaternary climate and ecologic changes (McDonald and McFadden, 1994;Monger et al, 1998;Lechler et al, 2018;Huth et al, 2019;Újvári et al, 2019Zamanian et al, 2021). Recent studies suggest a strong summer seasonal bias in some (Breecker et al, 2009;Passey et al, 2010;Quade et al, 2013;Huth et al, 2019) but not all pedogenic carbonates (Peters et al, 2013).…”

Detection of diagenetic alteration in bones and teeth for migration and dietary studies — a combined FTIR and C-N–O-Sr isotope study on tenth century CE cemeteries in northern and northeastern Hungary

“…Secondary carbonate is precipitated as a product of alteration induced by groundwater infiltration, primarily in the warmer seasons (Újvári et al 2019). Summer temperatures range from 19 to 22 °C in the area (Demény et al 2012;Újvári et al 2019), which serve as an upper limit of soil-related carbonate formation. The lower limit is the annual average of 10-11 °C (Czuppon et al 2018;Újvári et al 2019).…”

“…Summer temperatures range from 19 to 22 °C in the area (Demény et al 2012;Újvári et al 2019), which serve as an upper limit of soil-related carbonate formation. The lower limit is the annual average of 10-11 °C (Czuppon et al 2018;Újvári et al 2019). However, because carbonate formation predominantly occurs during the warmer seasons, the bone carbonate formation temperatures are closer to the upper limit.…”

The past in dust: current trends and future directions in Pleistocene geoarcheology of European loess

“…However, temperature and precipitation can be difficult to quantify and disentangle. A new method holds potential by using clumped isotopes applied to terrestrial carbonates providing soil and air temperature estimates for the summer season (Újvári et al ., 2019). δ 15 N is another stable isotope investigated in loess and is applied to soil biogeochemical cycles.…”