Wyniki wyszukiwania - BazTech

1

Reconstruction of sediment provenance and transport processes from the surface textures of quartz grains from Late Pleistocene sandurs and an ice-marginal valley in NW Poland

Woronko B., Pisarska-Jamroży M., van Loon A. J.

Geologos

|

2015

|

Vol. 21, No. 2

105--115

EN

During the Pomeranian phase of the Weichselian glaciation (~17–16 ka), the Toruń-Eberswalde ice-marginal valley (NW Poland and easternmost Germany) drained water from the Pomeranian ice sheet, while intensive aeolian processes took place across Europe in the foreland of the Scandinavian ice sheet (‘European Sand Belt’). The micromorphology of the quartz grains in the Toruń-Eberswalde ice-marginal valley shows no traces of these aeolian processes, or only vague signs of aeolian abrasion. This is unique among the aeolian sediments in other Pleistocene ice-marginal valleys in this part of Europe. The study of the surfaces of the quartz grains shows that the supply of grains by streams from the south was minimal, which must be ascribed to the climate deterioration during the Last Glacial Maximum, which resulted in a decrease of the discharge of these extraglacial rivers to the ice-marginal valley.

2

Uwarunkowania rozwoju pogrązów w aluwiach doliny Wisłoka w okolicach Rzeszowa (południowo-wschodnia Polska)

Superson J., Brzezińska-Wójcik T., Gębica P.

Przegląd Geologiczny

|

2013

|

Vol. 61, nr 2

127–-132

EN

The article presents the results of geological and geomorphological research concerning load-cast structures outcropping in the alluvial terrace sediments of theWisłok River in the Fore-Carpathian Erosional Valley. Given the large dimensions of these structures, reaching 1.5 m in some places, as well as their strong accumulation and diversity (i.e. drop-like and pocket-like structures), the authors attempted to establish the environmental factors that had determined the development of the structures in periglacial deposits of the Weichselian Glaciation. The structures were analysed in two accessible outcrops where sediments are represented by flood rhythmite and organic deposits, overlain by channel sands. Sandy load-cast structures occur in flood rhythmite and loamy deposits. The formation of load-cast structures probably started due to earthquakes in the Upper Pleniglacial period. The various shapes of load-cast structures were constrained by the various physical properties of the sediments and the escape of water during the deformation process.

3

Transformacja form korytowych na przykładzie aluwiów piaskodennych rzek roztokowych środkowego vistulianu w Kotlinie Toruńskiej

Weckwerth P.

Landform Analysis

|

2013

|

Vol. 25

169--177

PL

Wyniki badań sedymentologicznych prowadzonych w północnej części Kotliny Toruńskiej pozwoliły na rozpoznanie zmian architektury środowiska sedymentacji korytowej piaskodennych rzek roztokowych. Rzeki te funkcjonowały w czasie środkowego vistulianu, a ich osady należą do górnego ogniwa formacji z Zielonczyna. Ewolucja sedymentacji fluwialnej następowała w dwóch fazach, którym odpowiadają odmienne formy korytowe. W pierwszej fazie dno koryta roztokowego zdominowane było przez pojedyncze odsypy poprzeczne, zaś w drugiej doszło do rozwoju złożonych odsypów śródkorytowych w wyniku łączenia się odsypów pojedynczych. Główną przyczyną transformacji morfologii koryta rzeki była zmiana reżimu rzek z niwalnego na proglacjalny w czasie awansu czoła lądolodu w stadiale głównym zlodowacenia wisły oraz rozwój systemu pradolinnego. Transformacja morfologii koryt skutkowała także wzrostem tempa agradacji ich osadów.

EN

The results of sedimentological research documented changes of architectural elements of fluvial sedimentary environment of sand-bed braided rivers in the Toruń Basin. These rivers existed at the middle Weichselian and their deposits belong to the upper member of Zielonczyn Formation. The evolution of fluvial sedimentation took place in the two phases, which correspond to different channel macroforms. The braided river bed was dominated by a unit bars during the first phase, while in the second phase were evolved compound mid-channel bars as a result of the amalgamation of unit bars. The main causes of the transformation of river channel morphology in the area of the Toruń Basin during the Weichselian glaciation included changes in river regime from nival to proglacial and development of ice-marginal valley. Transformation of channel morphology resulted in an increase in the aggradation rate.

4

Paleogeograficzne uwarunkowania odpływu wód z zastoiska warszawskiego doliną Bachorzy i pradoliną warszawsko-berlińską w czasie stadiału głównego zlodowacenia Wisły

Molewski P.

Landform Analysis

|

2013

|

Vol. 25

105--114

PL

Autor przedstawia nową koncepcję odpływu wód z zastoiska, które utworzyło się w Kotlinie Warszawskiej podczas stadiału głównego ostatniego zlodowacenia. Podstawową, dyskutowaną kwestią jest możliwość odpływu tych wód pradoliną warszawsko-berlińską, w świetle współczesnych stosunków hipsometrycznych w jej wschodnim odcinku. Opracowany nowy schemat zasięgów lądolodu stadiału głównego zlodowacenia wisły umożliwia w starszej fazie tego stadiału (fazie leszczyńskiej) odpływ wód z zastoiska z pominięciem jej wschodniego odcinka przez dolinę Bachorzy. Autor rozważa również rolę halokinezy w zmianie stosunków hipsometrycznych we wschodniej części pradoliny warszawsko-berlińskiej.

EN

The author presents a new concept of the outflow from the ice-dammed lake that formed in the Warsaw Basin during the Main Stage of the last glaciation. The basic issue under discussion is the possibility of the outflow along the Warsaw-Berlin pradolina in the light of the contemporary hypsometric relations in its eastern section. A new scheme of the ice sheet ranges during the Main Stage of the Weichselian Glaciation reveals that during the older phase of this stage, the Leszno Phase, the outflow from the ice-dammed lake was possible through the Bachorza valley, i.e. omitting the Ice-marginal Valley’s eastern section. The author also considers the role of halokinesis in changing the hypsometrical conditions in the eastern part of the Warsaw-Berlin pradolina.

5

Is the Charlottenthal fan (marginal zone of the Pomeranian phase, NE Germany) an end moraine?

Pisarska-Jamroży Małgorzata, Börner Andreas

Geologos

|

2011

|

Vol. 17, No. 1

17--28

EN

The maximum ice-sheet extent of a glaciation or glacial phase is in most cases indicated by the position of end moraines. In some cases, however, the maximum extent of the ice sheet is indicated by a fan which represents the transitional zone between the end moraine and the proximal outwash plain (sandur). Such a fan from the Pomeranian phase near Charlottenthal in NE Germany has been investigated for its lithofacies, and the depositional mechanisms of the two sedimentary environments (end moraine and outwash plain) are reconstructed. The Charlottenthal profile is not characteristic in a sedimentological sense of a typical marginal end moraine or a sandur. The deposits represent subaerial debris flows, sheet floods and channelized currents, which are typically processes for transitional fan. Gravel samples from the till complex show typical Weichselian till compositions. These till compositions indicate a general transport direction from North to South, which is consistent with the known movement of the ice sheet during the Pomeranian phase of the Weichselian.

6

Palaeoglaciology of the Weichselian Odra ice lobe, NE Germany and NW Poland

Hermanowski P.

Landform Analysis

|

2010

|

Vol. 14

12-24

EN

Southern part of the Scandinavian Ice Sheet terminated in large lobes projecting tens of kilometres beyond the main ice sheet margin. One of the main ice lobe was the Odra lobe localized in NE Germany and NW Poland. In this study concise description of current morphology of the Odra lobe area is given with special reference to subglacial hydraulic conditions during the ice sheet advance. Subglacial conditions were simulated by using time-dependant three-dimensional numerical model, and obtained results were compared to geological observations. The results show entire groundwater system alternation that affected the ice/bed coupling and influenced formation of specific subglacial landforms. Coupling the simulation results with empirical estimates of basal melting rate suggests that only a small fraction of basal meltwater could have drained to the ice forefield as groundwater. Adverse slope of the low-permeable ice bed hampered water drainage, and led to water accumulation at the ice/bed interface that in turn facilitated basal sliding and bed deformation.

7

Unikalne stanowisko szczątków mamuta na Dolnym Śląsku

Wiśniewski A., Wojtal P., Krzemińska A., Zych J., Przybylski B., Badura J., Ciszek D.

Przegląd Geologiczny

|

2009

|

Vol. 57, nr 3

234-234

EN

Aunique set of mammoth bones and tusk was found in active gravel pit in vicinities of Zastruże near Żarów, Lower Silesia. The use of archaeological methods made it possible to uncover 17 bones belonging to a single individual (Mammuthus primigenius). This is the first record of so complete set of mammoth bones in the Lower Silesian region. Mammoth remains were found to be accompanied by some bones of a horse and a flint artifact. The mammoth bones were dated radiocarbon method at 23 790 š 160 years, that is at the beginning of the last Pleniglacial of the Weichselian Glaciation. The mammoth remains were embedded in slope sediments of a small valley so they did not occurin anatomical order.

8

Drenaż subglacjalny i jego wpływ na dynamikę lobu Odry zlodowacenia wisły

Hermanowski P., Piotrowski J. A.

Przegląd Geologiczny

|

2009

|

Vol. 57, nr 6

504-504

EN

In this paper we have analyzed the influence of the Weichselian ice sheet advance on the groundwater system in the Odra lobe area using hydrogeological numerical modelling performed with the finite difference method. The results indicate entire re-organization of the groundwater system in relation to non-glacial times mainly affecting the flow directions, velocities and fluxes. The re-organization of groundwater flow was caused by the pressure gradient imposed by the sloping ice sheet surface especially obvious under the ice margin and some distance in front of it. Simulated groundwater flow velocities are significantly higher than the present velocities in that area while the major groundwater flow direction is to the south, i.e. opposite to the present direction. Coupling the simulation results with assumed basal melting rate suggests that only a small fraction of basal meltwater [~24%) could have drained through the bed. The surplus water likely accumulated at the ice/bed interface facilitating faster ice flow of the Odra lobe due to enhanced basal sliding and bed deformation.

9

Terrestrial heat flow density in Poland - a new approach

Szewczyk J., Gientka D.

Geological Quarterly

|

2009

|

Vol. 53, No 1

125-140

EN

The Earth’s thermal field, particularly the heat flow density (HFD), is a valuable source of information on geodynamic processes within the Earth’s crust, conditions for hydrocarbon generation and on ar eas and formations promising for geothermal energy. Lithospheric thermal and rheological modelling is critically dependent on high-quality surface heat flow values. The available maps of heat flow density, not only for the area of Poland, are not reliable from the point of view of the current state of knowledge. The main critical factorin determining heat flow density is the knowledge of depth distribution of thermal conductivity. We used a new method of estimating the thermal conductivity from well logging data interpretation with control calibration based on laboratory determined thermal parameters. We con sider that the observed vertical variations of HFD in the shallow part of profiles (<2000 m) are mainly due to a Holocene warming. We have proposed a new original method of determination of HFD based on modelling of palaeoclimatic ef fect. Using this method, we have calculated new HFD values for 308 deep boreholes and completed a new map of this parameter for Poland, which is the first of this type. We propose to undertake a critical analysis of all the existing heat flow data not only for Europe that may change the present understanding of global heat flow.

10

Ślady zmian klimatycznych plejstocenu oraz holocenu w profilach temperatury w głębokich otworach wiertniczych na Niżu Polskim

Szewczyk J.

Przegląd Geologiczny

|

2002

|

Vol. 50, nr 11

1109-1114

PL

Zmiany klimatu jakie miały i mają miejsce na Ziemi mogą pozostawiać swoje ślady w postaci zmian temperatury obserwowanych obecnie w profilach otworów wiertniczych. Analiza głębokościowej zmienności tych temperatur może być źródłem informacji o warunkach klimatycznych jakie istniały na badanym obszarze w różnych okresach. Czynnik ten wpływa równocześnie na obserwowaną wielkość ziemskiego strumienia cieplnego i jego uwzględnienie może mieć istotny wpływ na poprawność wyznaczenia tego parametru. Na podstawie przedstawionych w pracy wyników analiz badań geotermicznych opartych zarówno na metodzie konstrukcji syntetycznych profilowań termicznych (Ts), jak i wykonanych modelowaniach geotermicznych przeanalizowano wpływ czynnika paleoklimatycznego związanego ze zlodowaceniem późnoplejstoceńskim na wartości temperatur obserwowanych obecnie w otworach wiertniczych na obszarze Niżu Polskiego. Wstępna interpretacja danych geotermicznych z ponad 30 głębokich otworów z tego obszaru pozwoliła między innymi na stwierdzenie obecności efektu paleoklimatycznego, a także naokreślenie średniej wartości temperatury warstwy przypowierzchniowej (GST) istniejącej na tym obszarze w okresie tego zlodowacenia. (-6.85 deg C).

EN

Past and current climatic changes on the Earth may be recorded in the subsurface temperature profiles observed in deep boreholes. Analysis of such profiles measured in boreholes few thousand metres deep may provide information on past climatic conditions existing in on the studied area. Terrestial heat flow data may be considerably influenced by this factor and should be corrected for all data accordingly. Results of analysis based both on constructions of synthetic thermal logs (Ts) and on the results of further modelling show that the last glaciation has left evident paleoclimatic temperature signals in nearly all observed subsurface temperature profiles in deep boreholes from the Polish Lowlands. Preliminary results on the average annual ground surface temperature for the Polish Lowlands in the Late Pleistocene have been obtained (GST = -6.8°C).