The upper Pleistocene loess-palaeosol sequence at solonovka on the Cis-Altai plain, west Siberia – First luminescence dating results

• Published in: Quaternary Geochronology
• Main Authors: Meshcheryakova, O. A., Volvakh, N. E., Kurbanov, R. N., Zykina, V. S., Zykin, V. S., Murray, A. S., Volvakh, A. O., Malikov, D. G., Buylaert, J. P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Dating; Late pleistocene; Loess; Luminescence dating; Stratigraphy; Western siberia; Kazantsevo; ob river; Siberia
• Online Access: https://pure.au.dk/portal/da/publications/the-upper-pleistocene-loesspalaeosol-sequence-at-solonovka-on-the-cisaltai-plain-west-siberia--first-luminescence-dating-results(1069d539-ad3b-48df-9881-4d449d61b180).html; https://doi.org/10.1016/j.quageo.2022.101384; http://www.scopus.com/inward/record.url?scp=85137306765&partnerID=8YFLogxK

Loess-palaeosol deposits of the Upper Pleistocene cover an extensive territory in the south of Western Siberia. Previously, most studies of loess-palaeosol sequences were carried out on river bank sections of the Ob river around Novosibirsk and upstream of this location (Ob Loess plateau); more recently, the focus of research has shifted towards the inner part of the Cis-Altai plain. Despite a good knowledge of the structure of regional loess-palaeosol sequences, there is a considerable lack of absolute dating beyond the radiocarbon limit. However, recent high resolution luminescence dating of a key Marine Isotope Stage 5 (MIS 5) stratotype at Lozhok has identified the presence of a long hiatus in the deposit. As a result, the published ages of the main units have been underestimated, because the existing chronology is largely based on palaeosol counting. This new observation argues for an urgent re-evaluation of the accepted chronostratigraphy of Western Siberian Late Quaternary. Here we present the first luminescence data for a loess-palaeosol sequence of the Cis-Altai plain, at the Solonovka key section, using both quartz optically stimulated luminescence and feldspar post-infrared infrared stimulated luminescence from 25 samples. The results show that the deposits were formed during the Late Pleistocene. The ∼1 m thick well-developed upper pedocomplex (PC1) has cryoturbation cracks filled with upper loess; this a characteristic regional benchmark for stratigraphic correlation. Two distinct hiatuses in sedimentation are found in the section: at the boundary of MIS 3/2, and after the formation of the MIS 5 Berdsk pedocomplex (PC3 and 2) until the beginning of the formation of MIS 3 deposits. The age of the thick PC3 palaeosol at the base of the section is determined as MIS 5, confirming evidence for the pronounced Kazantsevo (Eemian) interglacial in the loess-palaeosol record of Western Siberia. The results of our study emphasize the importance of understanding the palaeogeomorphological background to soil ...