Wyniki wyszukiwania - BazTech

1

Plant macrofossils from the Czyżów Complex deposits of the Szczerców outcrop, central Poland

Myśkow E., Krzyszkowski D., Wachecka-Kotkowska L., Wieczorek D.

Geology, Geophysics and Environment

|

2016

|

Vol. 42, no. 3

325--336

EN

The paper presents the results of research into the plant macrofossils found in the tectonic Kleszczów Graben, within Mesopleistocene sandy sediments. A number of samples were collected at eight locations from river sediments containing variously sized fragments of plants, mostly from greenish sands overlying Neogene sediments. The structural characteristics of the sediments show a cyclic record of the formation of point bars, their washing out at supercritical conditions, and their aggradation by fine-grained material during flow waning. Based on lithological and structural studies, it has been demonstrated that the sands accumulated in an environment of a meandering river, whose valley bottom was covered with fairly dense vegetation, inhibiting the influx of mineral material to the floodplain from the surroundings – the valley or glacial plateau slopes. The aim of further analysis was to identify the plant genera of the individual macrofossils (about 40 specimens). The most numerous macrofossils were observed in the middle layers of the profile, within sandy megaripple structures, where mostly fragments of Fraxinus and Acer wood were present. In other layers, several fragments of Pinus and three pieces of Populus wood were identified. Additionally, young stems of dicotyledonous plants and fragments of rhytidome (the outer bark of a tree) were found. The results are discussed in combination with considerations on the deposition of the Czyżów Complex in the Bełchatów outcrop, and on the occurrence of local flora.

2

Palaeoecology of the Holsteinian lake in vicinity of Wilczyn (eastern Poland) based on molluscan studies

Szymanek M.

Geological Quarterly

|

2013

|

Vol. 57, No. 4

637–-648

EN

Malacological studies of two profiles of the Holsteinian (Mazovian) Interglacial from eastern Poland – Roskosz and Wilczyn 1/12 – are presented. They are connected with the northern part of the Wilczyn palaeolake and seems to document palaeoecological changes in the part of the climatic optimum and the post-optimal period. Mollusc communities are typical of lake environs. The latter is supported by biometry of Pisidium moitessierianum. Higher energy conditions are evidenced by rheophile species P. henslowanum and P. nitidum in the lowermost part of the Roskosz section. Mollusc assemblages with Lithoglyphus jahni, with Valvata piscinalis and Bithynia tentaculata as well as with Valvata piscinalis are distinguished at Roskosz. They record changes in aquatic vegetation and depth conditions. Malacofauna from Wilczyn 1/12 is dominated by V. piscinalis, V. piscinalis f. antiqua and B. tentaculata. Limited contribution of temperate gastropods Viviparus diluvianus and L. jahni as well as the occurrence of some cold-loving forms indicate a deterioration of thermal conditions. Shallow-water habitats and expansion of reed zones are inferred from proportions of Bithynia shells and opercula.

3

Malacofauna of the Holsteinian lake deposits at Hrud II (Eastern Poland) and its palaeoecological significance

Szymanek M.

Geological Quarterly

|

2012

|

Vol. 56, No 1

117-126

EN

Mollusc-bearing deposits at Hrud II (Eastern Poland) accumulated in the western part of a palaeolake of Holsteinian age (MIS 11). The faunal assemblage is typical of freshwater environments and presumably represents a part of the interglacial climatic optimum (Carpinus–Abies Zone). On the basis of its varied composition, the evolution of the water body is described. Reinterpretation of the data from the eastern part of the lake (Hrud I) and combining of the results from both sites enable a wider palaeoecological reconstruction. Fluctuations in lake level, water dynamics and changes in the aquatic vegetation are inferred from quantitative relations between selected molluscs, especially Lithoglyphus jahni, Valvata piscinalis and Bithynia tentaculata, which prevail in the deposits investigated. A predominance of Valvata piscinalis indicates a rise in water level, whereas the communities with abundant Bithynia opercula are typical of a more shallow lake with rich reed fields. Amelioration of the trophic conditions between the pre-optimal and optimal part of the Holsteinian Interglacial can also be recognised.