Micromorphology of sand quartz grains from the preglacial Kozienice series as an indicator of transportation and deposition processes in the southern Mazovian Lowland

W celu określenia charakteru osadów źródłowych, warunków transportu i depozycji osadów preglacjalnych akumulowanych na Nizinie Mazowieckiej, przeanalizowano je pod kątem mikromorfologii powierzchni ziaren kwarcowych frakcji piaszczystej (0,8–1,0 mm) analizowanej w skaningowym mikroskopie elektronowym (SEM). Badaniom poddano osady ze stanowisk Stanisławice, Brzóza, Januszno i Mościska. Uzyskane wyniki pokazują, że niezależnie od położenia i wykształcenia facjalnego reprezentują one wyłącznie środowisko wysokoenergetyczne wodne. Najbardziej charakterystyczną cechą osadów preglacjalnych jest bardzo słaby, jednakowy dla wszystkich ziaren, stopień ich obtoczenia. Dominującym procesem kształtującym powierzchnię badanych ziaren było trawienie chemiczne postępujące w czasie ich transportu w środowisku wodnym. Efektem tego procesu jest powstanie błyszczącej, gładkiej powierzchni określanej jako dulled surface. Abrazja mechaniczną miała jedynie drugorzędne znaczenie w modelowaniu ich powierzchni. Najbardziej prawdopodobne jest, że dla utworów preglacjalnych źródłowe mogły być zwietrzeliny osadów o cechach wręcz identycznych do nich. Ich transport najprawdopodobniej odbywał się na stosunkowo krótką odległość.Surface micromorphology of quartz sand grains (0.8–1.0 mm) of preglacial sediments from the Mazovian Lowland (Poland) was analysed under scanning electron microscopy (SEM) in order to determine characteristic features of source material, and conditions of transport and deposition of the sediments. Samples were taken from the Stanisławice, Brzóza, Januszno and Mościska sites. Research results show that all the analysed grains represent a high-energy aqueous environment, irrespective of location and facies setting. The most characteristic features of the preglacial sediments is a very poor grain rounding, equal in all cases. Chemical etching progressing during transportation of the sediments was a dominant process shaping the micromorphology of the grains. This process led to development of a shiny, smooth grain surface called „dulled surface”. Mechanical abrasion played only a secondary role. Most probably, the preglacial deposits sourced from weathered sediments which had apparently identical features as the analysed sediments. They were transported most probably over a very short distance

The runoff structure in the Nida differential river basin

1. Alimentation of the researched system. In the years 1971-1998, an average 0.698 km³ of water alimented the researched system annually. Of this volume, merely 22 per cent originated by precipitation, while the remaining amount was the inflow from the upper course of the Nida, which therefore had a dominant influence on the regime of the researched section of the river. The temporal distribution of flow coefficient (Parde) did not change between the cross sections closing the system. The temporal distribution of both inflow variables is uneven. With regard to precipitation inflow, the privileged months are June, July and August. In case of river inflow, on the average the largest water volumes aliment the system in the spring. At the same time, the maximum flow values are reached in July and August. The inflow to the river basin is point-like, whereas the precipitation inflow is spatially varied, with the right-bank part of the basin collecting the major part of water. The distribution of precipitation is affected by such factors as the Nida valley. This is particularly well visible in June, July and August (up to 10 per cent difference in precipitation volumes), in the winter months it is an insignificant phenomenon. 2. Runoff conditions in the differential river basin subsystem The differential river basin subsystem is varied in terms of physiogeographic conditions. It is made up of three units: the Wodzisław Hummock, the Pińczów Hummock and the Solec Basin, which bears upon the runoff conditions. This is manifested by differences in the density of the drainage system, ranging from 0.36 km/km² in the Wodzisław Hummock to 0.85 km/km² within the Solec Basin. This picture is disturbed by artificial watercourses, which represent 45 per cent of the entire drainage network. If we compare the runoff conditions in the left-bank and right-bank parts of the river basin, we can observe that in the latter they are markedly worse. Measured at high water stages (in July 1999), the unit runoffs reached the values of merely 1.151 skm/skm² to 2.031 skm². In the left-bank part of the river basin, the unit runoff was definitely higher and more varied. The best runoff conditions were recorded in the gypsum karst of the Solec Basin and at the base of the Pińczów Hummock. Maximum unit runoffs measured in July 1999 reached 15.31 skm². In the years 1971-1998, the average unit runoff from the entire researched subsystem was high and amounted to 5.61 skm². In the wet years, it reached 10.711 skm², while in the dry ones it fell to 3.22 skm². The average runoff coefficient ( 1971-1998) reached 32 per cent. 3. The functioning of the Nida subsystem. The Nida valley constitutes a separate physio-geographic unit. In the early 1970s, it was strongly transformed by man owing to the regulation of the Nida channel, construction of drainage ditches and accompanying hydrotechnical facilities. All this resulted in reduced retention role of the valley in the area of Pińczów. Nonetheless, the valley's retention function was still visible in transforming high water stages. This particularly applied for summer high water stages, whose maximum flows normally diminished along with the river flow. During thaw flows, this was not as obvious, which could be associated with ice phenomena. The transformation period of the maximum flow normally lasted two to three days. In the researched section, the Nida, primarily performs a transit role. In the years 1971-1998, on the average the Nida river channel annually transported 0.546 km³ of water from the upper part of the river basin. The side tributary alimentation from the differential catchment area subsystem represented only eight to nine per cent of this volume. It was primarily water produced by the drainage of the abundant subterranean waters. The waste water discharged to the Nida represented approximately six per cent of the annual average of side tributary alimentation

The history of glaciation of the Łomnica Valley in Karkonosze as shown by the quartz grain surface micromorphology records

The Łomnica Valley (Karkonosze Mountains, Sudety Mountains) was glaciated during the Pleistocene. The question if the valley was glaciated once or more times is still not answered despite many research methods were used in numerous investigations. To answer the question and reconstruct the conditions accompanying the process of sediment transport in the glacial environment, the analyse of micromorphology of sand quartz grain surfaces in SEM (Scanning Electron Microscope) was used. The survey was conducted on the youngest and the oldest known moraine deposits occurring along the whole valley floor. The glacial deposits were compared to the waste deposits. Obtained results confirmed that the valley had been glaciated at least twice in the Pleistocene and that the conditions of glacial transport had varied

Nebkas - forms of forced aeolian accumulation of the eastern margin of the Chott Jerid

The article includes description of nebkas - the smallest accumulation forms of aeolian origin. They originate from accumulation of wind-blown material accumulated on a lee side of a vegetation obstacle. The research was undertaken in the eastern part of the Chott Jerid, within its Holocene floor. Such forms are thought to indicate erosion of arid regions. Their appearance is usually linked to lowering of ground water table and related change in vegetation density. The researched was focused on two selected fields of nekbas. Morphometry and sedimentological features of building material were analysed. It was found that the shape of nebkas depends on a type of vegetation which constitutes the transport obstacles and forces accumulation. Lower forms (up to 0,5 m high) are created on a lee side of arfej species and are characterised by a high to length ratio 1:7 and so they have a typical shape of nebkas. Higher forms (up to 1 m) are created on a lee side of tamarix species and their high to length ratio is 1:4. Such a shape is due to a width of the plant and intensive erosion of a distal part of the form because wind frequently changes direction in this field. Sedimentological features of the forms show that material building the higher forms is better sorted comparing with lower forms and therefore it was probably transported for a longer distance. Mineral-lithological composition of the forms show a high share of quartz as well as relatively high share of gypsum (not resistant for abrasion). High content of gypsum in nebkas, seasonal capillarity with intensive evaporation lead to crusting of especially lower forms. Such a crusting strengthens the forms, protects from erosion of their distal parts and therefore explains differences in shapes of nebkas

Microstructural and microtextural features of glacial tills as an indicator of subglacial conditions on the example of Lusowo (Poznan Lakeland)

Wielokierunkowym badaniom sedymentologicznym poddano gliny lodowcowe budujące wysoczyznę morenową rozciągającą się na południe od moren czołowych fazy poznańskiej zlodowacenia wisły. Teren badań zlokalizowano około 10 km na NW od Poznania. W jego obrębie zaznacza się obecność wielkoskalowych lineacji glacjalnych, będących efektem funkcjonowania w czasie zlodowacenia wisły szybkiego paleostrumienia lodowego. Przeprowadzono analizy: litofacjalną osadów, uziarnienia, charakteru powierzchni ziarn kwarcu frakcji piaszczystej według Cailleux (1942) i w SEM oraz analizę mikrostrukturalną na podstawie płytek cienkich. Uzyskane wyniki pozwoliły wnioskować o prawdopodobnym źródle osadów. Ponadto uwidoczniła się duża jednorodność osadów pod względem uziarnienia, jak również charakteru obtoczenia i zmatowienia powierzchni ziarn kwarcu frakcji 0,8-1,0 mm oraz znikomy wpływ transportu w środowisku glacjalnym na charakter mikrorzeźby powierzchni ziarn kwarcu. Natomiast wyniki analizy mikrostrukturalnej płytek cienkich pokazały zróżnicowanie glin lodowcowych w profilu pionowym, odpowiadające zmiennym warunkom towarzyszącym akumulacji osadów. Zapis mikrostrukturalny uwidocznił obecność ciągłej, ale o zmiennej miąższości warstwy deformacyjnej. Czynnikiem modelującym zmiany była zawartość i ciśnienie wody porowej.Multiproxy sedimentological analyses were carried out on glacial till building morainic plateau which extends south from the terminal moraines of the Pomorska phase, Vistulian Glaciation. The study area was located about 10 km to the north-west from Poznań. Mega-scale glacial lineations occur among the plateau. They are the effect of a fast flowing paleo- ice stream existing during the Vistulian Glaciation. Following analysis were performed: lithofacial analysis of sediments, the granulometric composition of deposit, the frosting and rounding analyses of sand quartz grains (1.0–0.8 mm) according to Cailleux (1942) and in SEM and analysis of thin sections. The results suggest probable source of the deposits and show homogeneity in terms of granulometry and rounding and frosting of quartz grains in fraction of 0.8-1.0 mm. Glacial transport appears to have limited influence on the microstructure of quartz grains surface. Analysis of thin sections show the vertical differentiation of glacial till according to variable conditions accompanying its deposition. Microstructures recorded continuous deformation layer which varied in thickness. The volume and pressure of pore water were the factors responsible for the changes

Texture features of Pleistocene deposits as a source of information on sedimentary environment conditions; a case study of Glinojeck borehole (Raciąż Plain)

Analysis of the texture of sediments from the Glinojeck borehole (sheet Sochocin) allowed to better understand conditions of their accumulation environment. Sandy sediments were divided into fluvioglacial, fluvioperiglacial and fluvial units. Rate and duration of the accumulation processes were determined. The analysis also allowed to distinguish between thick units of glacial till. No sediments representing climatic optimum of any interglacial were found in the borehole since the sediments must have been accumulated in harsh environmental conditions (sparse vegetation and intensive aeolian processes during the Małopolanian and Great Interglacials)

Stratigraphical position of lower Pleistocene sediments in Southern Podlasie Lowland - discussion

W trzech wierceniach Budziska (ark. Okrzeja), Wola Chomejowa i Kolonia Bronisławów (ark. Adamów), wykonanych na potrzeby Szczegółowej mapy geologicznej Polski w skali 1:50 000 w południowej części Niziny Południowopodlaskiej, stwierdzono duże rozbieżności w wynikach wykonywanych analiz. Analiza obtoczenia i zmatowienia ziarn kwarcowych frakcji piaszczystej stwierdza, że charakteryzuje je bardzo wysoki udział ziarn kształtowanych w środowisku eolicznym. Natomiast wyniki analizy palinologicznej korelują badane osady z miocenem lub eocenem, t.j. okresami, w których nie notuje się obecności procesów eolicznych. Ponadto wyniki analizy minerałów ciężkich i uziarnienia badanych osadów pozwalają sądzić, że najprawdopodobniej osady poniżej gliny sanu 1 można korelować ze schyłkiem preglacjalnym lub z okresem bezpośrednio poprzedzającym nasunięcie najstarszego na tym terenie lądolodu zlodowacenia narwi. Ochłodzeniu towarzyszył intensywny rozwój procesów eolicznych na obszarach znajdujących się w strefie peryglacjału, rozciągającej się na południe od maksymalnego zasięgu tegoż lądolodu. Transportowany przez wiatr materiał był składany w dolinach rzecznych. Neogeńska flora notowana w analizowanych osadach najprawdopodobniej znajduje się na wtórnym złożu. Może być związana z intensywną erozją starszych osadów przez wody rzeki pra-Wieprza lub pra-Krzny.Sedimentological analysis were preformed on samples taken from three boreholes: Budziska (Okrzeja sheet), Wola Chomejowa and Kolonia Bronisławów (Adamów sheet) drilled for need of the Geological map of Poland in a scale 1:50,000 in the southern part of the Southern Podlasie Lowland. Some significant discrepancies in certain features of the sediments are observed: high share of rounded and frosted quartz sand grains show aeolian environment of sedimentation. However according to the results of palynological analysis, the sediments were deposited in Miocene or Eocene periods, when aeolian processes are thought to be rather absent. Moreover, results of heavy minerals analysis and sieving analysis allow to infer that sediments lying under glacial till of San 1 can be correlated with the end of Preglaciation or with a period directly preceding oldest glacial transgression in this area, the Narevian Glaciation. During climate deterioration aeolian processes intensified in the periglacial zone south of the maximum glacial extend. Wind transported material was accumulated in river valleys. Neogene flora found in these sediments was probably redeposited and originated from older sediments eroded by the pra-Wieprza or pra-Krzna rivers

Upper Pleistocene and Holocene deposits at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

An abandoned ozokerite mine (= Ropyshche), where large mammal remains were discovered in the first half of the 20th century, is located in the Velyky Lukavets River valley covered with Quaternary sediments. The catchment area includes a flysch sequence unconformably overlain by salt-bearing Lower Miocene molasses of the Vorotyshcha beds. Both the Upper Pleistocene and Holocene are represented by: channel (gravel, sandy gravel) and overbank alluvium (mud, peat, biogenic mud) and colluvium (mud, sandy mud) as well as by mine wastes. The channel sediments are usually found in the lowest fragments of the borehole logs and represent mainly material deposited in the straight segments of meandering river-beds. The most common, fine-grained (Mz = 61.33 to 7.11 ?m), distal floodplain sediments are locally up to 10 m thick and are dominated by massive mud lithofacies, which contain frequent burrows, root hairs or slightly larger root traces and reed rods. These sediments are characterized by rather stable grain size distribution, quite monotonous mineral composition, presence of resistant heavy minerals and quartz grains with traces of chemical weathering. Angular grains with conchoidal fractures and sharp edges also occur. Therefore, textural features show that the main sources of material were, most probably, weathering crusts of various ages developed on relatively poorly lithologically diversified Carpathian flysch strata and on Miocene deposits of the Carpathian Foredeep. With time, an increase of the content of material originating from mechanical weathering (frost action) occurred in the floodplain deposits, which can be linked to an increase of climate severity and reduction of vegetation. However, these changes are not recorded in the deposits, which developed mostly in closed hollows and accumulated mainly from suspension or from low-energy flows. This calm sedimentation was periodically interrupted by supply of more coarse-grained material (sand, gravel). A distinct predominance of overbank deposits in the sections documented by their thickness suggests that the northward flow of the Velyky Lukavets River was blocked as a result of either neotectonic movements or damming of the valley by landslide tongues. From the lithological point of view, the most favourable conditions for preservation of large, extinct mammals still exist in the two selected areas, where the total thickness of Pleistocene muds exceeds 2 metres. The first area is located in the vicinity of boreholes Nos 2, 3, 21, 22, 23, 28, 30 33 and 36N, and the other, smaller one, is placed around borehole No. 42