Characteristics of Late Pleistocene and Holocene dune activity and soil formation in the Podravina, NE Croatia

Abstract The Đurđevac Sands constitute a wide area of small-scale dune relief in the Podravina (NE Croatia), located along the central part of the southern Drava River valley. Even though it has been the subject of earlier investigations, the timing and characteristics of aeolian activity and pedogenesis remain unclear. In this study, field investigations and laboratory methods are combined to gather information on past aeolian systems in the southern part of the Pannonian Basin. The results indicate that weak soil formation during the Bølling-Allerød interstadial stabilized the dunes after the first episode of aeolian activity that took place since ca. 18 ka. The source material for dune building is thought to be fluvial sand from the Drava River, which was blown from exposed terraces. During the Younger Dryas and/or Early Holocene, a new phase of aeolian activity is recorded, with material showing stronger evidence of weathering compared to the underlying aeolian material. Finally, during the Mid and/or Late Holocene, dunes were overbuilt once again with fresh unweathered sand. In general, these new findings obtained from the Đurđevac Sands area correlate rather well with other regions in the Pannonian Basin, in terms of the timing and characteristics of soil formation and aeolian activity.