Geological setting and sedimentary characteristics of the coversands distributed in the western part of the Blonie glaciolacustrine basin (Central Poland) - Preliminary results

The coversands distributed in the Blonie glaciolacustrine basin, west of Warsaw (Central Poland) were investigated. Textural features including grain size, rounding and frosting of quartz grains and mineralogical-petrographic composition in the sandy fractions (0.5–0.8 and 0.8–1.0 mm) were examined and the types, dynamics, regime and variation in processes during the formation of the coversands were determined. The sands are characterized by the prevalence of quartz and lack of micaceous minerals. Moreover, the relatively high content of partially rounded, matt (EM/RM) and well-rounded (RM) quartz grains, typical of aeolian sedimentary conditions, was certified. Hence, the results show a high aeolization degree of the investigated sediments, thus correlating them with aeolian deposition in dry, periglacial conditions after drying up of the Warsaw ice- dammed lake

New data about orgin and age of fan - like forms in the southern Mazovian Lowland

Południowa część Niziny Środkowomazowieckiej wykształcona jest z reguły jako prawie płaska powierzchnia zbudowana z osadów piaszczystych. Została ona określona mianem form stożkopodobnych. Szczegółowa analiza cech teksturalnych wskazała na eoliczne środowisko depozycji osadów. Rozwój form odbywał się w czterech etapach podczas środkowego i górnego vistulianu.The southern Mazovian Lowland is a almost flat plain build of fine- and medium-grained sands as a rule. It has been described as a fan-like forms. Detailed textural analysis indicated aeolian sedimentary environment. Forms were developed in four phases during middle and upper vistulianu

Upper Pleistocene palaeoenvironmental changes at the Zwierzyniec site, Central Poland

The paper presents the data on an Eemian–Late Glacial sedimentary sequence from the Zwierzyniec site, central Poland. A number of boreholes document one or two organic layers that occur beneath one or two horizons of clayey and silty deposits of ice-dammed lakes. This study demonstrates to which extent the Zwierzyniec site can contribute to a better understanding of the palaeoenvironmental changes during the Eemian–Vistulian time-frame in central Poland. To study it, a multi-proxy approach was applied, involving: palynological and plant macrofossil analysis, study of rounding of quartz grains and morphology of their surface, and investigations of sand mineralogy and till petrography. The results show that a till bed is overlain by a sandy series corresponding to the glacial-interglacial transition. Either one or two distinct peaks of organic accumulation are evidenced by peat horizons. The lower horizon records spectra with hazel and hornbeam, and did, therefore, accumulate in the Eemian. Observed only in some boreholes, the upper peat horizon marks the Brørup (or the lower part of the Rederstall stadial) represented by forest-steppe conditions with patchy mosaics of larch and further transition into sedges and herbaceous taxa. Localized in between the two peat sequences, the sandy horizon marks a long-lasting aeolian transformation with weathering by frost in the Early Vistulian. Again, significant changes of the palaeoenvironmental regime occurred, and are manifested in the one or two horizons of the glaciolacustrine sediments. This corresponded to the last glaciation in the region, when the ice-dammed lakes formed during the Main Stadial