Chronological Assessment of the Balta Alba Kurgan Loess-Paleosol Section (Romania) – A Comparative Study on Different Dating Methods for a Robust and Precise Age Model

Abstract

Loess-paleosol sequences (LPSs) are important terrestrial archives of paleoenvironmental and paleoclimatic information. One of the main obstacles for the investigation and interpretation of these archives is the uncertainty of their age-depth relationship. In this study, four different dating techniques were applied to the Late Pleistocene to Holocene LPS Balta Alba Kurgan (Romania) in order to achieve a robust chronology. Luminescence dating includes analysis of different grain-size fractions of both quartz and potassium feldspar and the best results are obtained using fine-grained quartz blue‐stimulated and polymineral post-infrared infrared-stimulated luminescence measurements. Radiocarbon (14C) dating is based on the analysis of bulk organic carbon (OC) and compound-specific radiocarbon analysis (CSRA). Bulk OC and leaf wax-derived n-alkane 14C ages provide reliable age constraints for the past c. 25–27 kyr. CSRA reveals post-depositional incorporation of roots and microbial OC into the LPS limiting the applicability of 14C dating in older parts of the sequence. Magnetic stratigraphy data reveal good correlation of magnetic susceptibility and the relative paleointensity of the Earth’s magnetic field with one another as well as reference records and regional data. In contrast, the application of paleomagnetic secular variation stratigraphy is limited by a lack of regional reference data. The identification of the Campanian Ignimbrite/Y-5 tephra layer in the outcrop provides an independent time marker against which results from the other dating methods have been tested. The most accurate age constraints from each method are used for two Bayesian age-depth modeling approaches. The systematic comparison of the individual results exemplifies the advantages and disadvantages of the respective methods. Taken as a whole, the two age-depth models agree very well, our study also demonstrates that the multi-method approach can improve the accuracy and precision of dating loess sequences.

Disentangling Sedimentary Pathways for the Pleniglacial Lower Danube Loess Based on Geochemical Signatures

“…The investigated section is 10.9 m thick. The chronological framework for this section is based on an integrative age model, using luminescence dating, radiocarbon dating as well as (palaeo-) magnetic correlation (Scheidt et al, 2021).…”

“…A correlative age model (Supplementary Material 3, Figure S1) was established based on published age models for the investigated LPS URL and VLA (Obreht et al, 2017), RAS (Zeeden et al, 2018), and BAK (Scheidt et al, 2021). SAG was correlated based on tephrochronological evidence and trends in magnetic susceptibility.…”

Significance of the Ukrainian loess-palaeosol sequences for Pleistocene climate reconstructions: rock magnetic, palaeosol and pollen proxies

“…Despite of significant amount of data obtained by Quaternary geology and palaeogeography, the forecasts of future climate change differ significantly. Therefore, nowadays a great attention is paid to implementation of new research methods within a multidisciplinary approach, to the search of new complete sections within the terrestrial archives, and to analysis of the factors that have caused palaeoenvironmetal changes [Vandenberghe, Nugteren, 2001;Buggle et al, 2013;Sümegi et al, 2015Sümegi et al, , 2019Marković et al, 2018;Zeeden et al, 2018;Chmielowska, Woronko, 2019;Molnár et al, 2021;Scheidt et al, 2021;Wacha et al, 2021].…”

A Detailed Paleoclimate Proxy Record for the Middle Danube Basin Over the Last 430 kyr: A Rock Magnetic and Colorimetric Study of the Zemun Loess-Paleosol Sequence

“…The most prominent tephra layer preserved in Eastern European loess and archeological deposits is the Campanian Ignimbrite/Y5 tephra (Veres et al, 2013;Giaccio et al, 2017). Dated to c. 40 ka BP, it provides an exceptional tie-point for linking records within MIS 3 and in testing the accuracy of luminescence and radiocarbon dating for loess records (Constantin et al, 2012;Fitzsimmons et al, 2013;Anechitei-Deacu et al, 2014;Obreht et al, 2016Obreht et al, , 2017Scheidt et al, 2021). However, several more tephra layers have been identified in south-eastern European loess profiles (see Marković et al, 2015Marković et al, , 2018 which, if well assessed, not only chronologically but also by their bulk sediment geochemical (see Pötter et al, 2021) and magnetic properties (this work) may serve as important anchor points for more secure lateral stratigraphic correlations (Zeeden et al, 2018).…”