Lithological diversity of the deposits of closed depressions in central Poland as a result of their origin conditions Aleksandra Majecka a, * , Jacek Forysiak b , Leszek Marks a , Anna Toloczko-Pasek a a Faculty of Geology, University of Warsaw, Al. _ Zwirki i Wigury 93, 02-098 Warszaw, Poland b Department of Geomorphology and Paleogeography, Institute of Earth Sciences, University of L od z, Narutowicza 88, 90-139 L od z, Poland article info Article history: Received 29 March 2017 Received in revised form 7 February 2018 Accepted 16 February 2018 Available online 19 March 2018 Keywords: Central Poland Closed-drainage depression Infillings of kettle-holes Lithology Origin abstract Small closed-drainage depressions are a common element of the landscape of Central Poland. Their origin is mainly connected to the melting of blocks of dead ice in the phase of advanced recession of the ice-sheet in the Wartanian Stadial of the Odranian Glaciation. In the L od z Upland, an analysis of four sites containing sets of depressions has been conducted to determine the lithological properties of their infillings. The analysis revealed that the frequently deep, steep-walled basins are filled in with deposits of various age and origin. Four lithological units, containing sediments ranging from a glacial base to the mineral sediments of the Vistulian, were formed. Many of the depressions do not contain biogenic sediments of the Eemian Interglacial. The lithological suggestions of the age of the deposits allowed to determine two types of depressions - fossil depressions of melting origin, and genetically complex ones that underwent deposition prior to the Eemian Interglacial and with a secondary deepening, most likely as a result of melting of ground ice under thermokarst conditions, during the Vistulian Glaciation (¼Weichselian). The dominant views that connect the origin of the multiple depressions solely to the end of the Wartanian should be verified. © 2018 Elsevier Ltd and INQUA. All rights reserved. 1. Introduction Small depressions are a common element in the landscape of Central Poland. They have a minor influence on the differentiation of the morphology of the terrain and they can be found mainly in closed-drainage areas, watershed zones and upper sections of dry denudation valleys, usually in assemblies of several forms. They appear in glacigenic uplands and have a largely similar origin - they formed as an effect of the melting of blocks of dead-ice during the post-maximum stadial (Wartanian) of the Odranian Glaciation. This cool stage, previously described as a separate glaciation (Lindner, 1992), corresponds to the Marine Isotope stage MIS 6 and to the Saalian Glaciation in Western Europe (Huissteden et al., 2003). This type of hollows is a landscape feature characteristic of the entire North European Plain. The plain stretches to the north of the Ardennes, the Bohemian Massif and the South Polish Uplands, to the south of the Baltic Sea and the North Sea, to the west of the lowlands of Flanders, to the Polish Lowland. Data from multiple European sites and analyses related to their climatic zones and the paleotemperature values may be found in the works of Aalbersberg and Litt (1998) or Turner (2000). A common trait of the documented closed-drainage depressions is the presence of biogenic Eemian deposits. They testify to the Wartanian age of the basins and confirm that there existed a lake district in the period of the last interglacial in the North European Plain. These depressions received substantial interest in the research of the Late Pleistocene, mostly because of the relevance of their infillings (sediments in superposition) to the reconstruction of the paleoenvironment and paleoclimate (e.g. Klatkowa, 1990, 1997; Aalbersberg and Litt, 1998; Turner, 2000). Numerous documented sites contain a repository of information on the environmental transformations during the entire glacial-interglacial cycle since the Saalian, through the continuous succession of the Eemian Interglacial and the Early Vistulian (¼ Early Weischselian). During the Wartanian Stadial in Poland, the ice sheet occupied southern Wielkopolska, the L od z Upland, Mazovia and southern Podlasie (Fig. 1)(Marks et al., 1995; Lindner and Marks, 1999). Apart from northern Wielkopolska, ice sheet did not amass in these areas during the Vistulian Glaciation. That is why in this area, depressions * Corresponding author. E-mail addresses: a.majecka@uw.edu.pl (A. Majecka), jacek.forysiak@geo.uni. lodz.pl (J. Forysiak), leszek.marks@uw.edu.pl (L. Marks), atoloczko@student.uw. edu.pl (A. Toloczko-Pasek). Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint https://doi.org/10.1016/j.quaint.2018.02.018 1040-6182/© 2018 Elsevier Ltd and INQUA. All rights reserved. Quaternary International 501 (2019) 208e218