PALEOCLIMATIC RECONSTRUCTION OF THE TURONIAN FLORA OF THE BELEUTY RIVER

Abstract

This study presents a quantitative reconstruction of the climatic conditions associated with the Turonian flora of the Beleuty River locality, situated within the present-day Ulytau Region of Kazakhstan. Paleoclimate reconstruction was performed using the Coexistence Approach based on the climatic ranges of nine nearest living relatives (NLRs) of fossil plant taxa. Climatic data for the selected NLRs were obtained from the Palaeoflora Database, version 2024. Seven climatic parameters were reconstructed: mean annual temperature (MAT), cold month mean temperature (CMT), warm month mean temperature (WMT), mean annual precipitation (MAP), and precipitation of the wettest (MPWET), driest (MPDRY), and warmest (MPWARM) months. The reconstructed intervals were 18.6–25.0 °C for MAT, 8.1–19.8 °C for CMT, 25.0–29.5 °C for WMT, 585–1613 mm for MAP, 125–245 mm for MPWET, 3–43 mm for MPDRY, and 38–206 mm for MPWARM. The results indicate generally warm climatic conditions and suggest marked seasonal variability in precipitation. Sensitivity analysis revealed that Bauhinia sp. strongly controls the lower temperature limits. When this NLR was excluded, the lower limits decreased to 13.8 °C for MAT, 1.8 °C for CMT, and 19.3 °C for WMT, whereas all precipitation intervals remained unchanged. These results provide new quantitative constraints on the continental paleoclimate of Central Kazakhstan during the Turonian.