Late Pleistocene pedogenesis and loess magnetism in northwestern Ukraine

Abstract The central European loess-paleosol sequence (Marine Oxygen Isotope Stage (MIS) 6–2) at three sites located in northwestern Ukraine, in the transitional area between the oceanic and continental climates, has been studied using micromorphological, grain-size, pollen, and magnetic methods. The sequence is characterized by a well-developed pedocomplex S1 (correlative of MIS 5), comprising four soils, and three interstadial soils within loess L1 (MIS 4–2). The soils of S1 are synsedimentary, indicating a dynamic depositional environment with pulses of aeolian sand sedimentation from late MIS 6 to MIS 5a. From various cryogenic features, the permafrost aggradation for MIS 6, 4, and 2, and deep seasonal freezing for MIS 5d and 5b were reconstructed. Distinct redoximorphic features of the loess units, widespread solifluction, well-developed periglacial phenomena, and very low magnetic susceptibility values for the loess-paleosol sequence of northwestern Ukraine reveal its similarity to those of the central European loess subdomain of the northern European loess belt. The low concentration of ferrimagnetic minerals in the parent material and intensive processes of physical and chemical weathering are reflected in the specific model of magnetic enhancement of the studied sequence, which is transitional between the “Chinese” (pedogenic) and “Alaskan” (reducing-pedogenic) models.