New Rock- and Paleomagnetic Data on Quaternary Deposits of the Tologoi Key Section, Western Transbaikalia, and Their Paleoclimatic Implications

Abstract—An integrated study combining laser granulometry, rock-magnetic, and paleomagnetic investigations is conducted for the deposits of the Tologoi section (51°44′43.93″ N, 107°28′20.93″ E)—a reference one for the Late Cenozoic of Western Transbaikalia. By jointly analyzing the rock-magnetic and granulometric data, we have more accurately determined the detailed stratigraphy of the section and identified the horizons of buried soils that were previously not known. Based on the paleomagnetic data, we established the position of the Matuyama/Brunhes magnetic boundary which allowed us to create an age model for the deposition of sediments composing the section. The rock-magnetic and granulometric characteristics clearly subdivide the section into the lower and upper parts which were formed in different conditions. The upper part was dominated by the slope processes whereas aeolian processes prevailed in the lower part. Using the anisotropy of magnetic susceptibility (AMS) data, we determined the prevailing wind directions as well as the slope direction and slope angle during the periods of sediment accumulation. A number of stratigraphic gaps were assessed from the correlation analysis of all the obtained empirical data. Based on the reconstructed sedimentation conditions, climatic fluctuations in the region in the Pleistocene were evaluated.