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Home Briefly about the project in English

The research project:
“Reconstruction of the Vistula ice stream lobe during the Main Stage of the Last glaciation on the basis of sedimentological and geomorphological signature in geospatial record”

The project is financially supported by the Polish Ministry of Science and Higher Education on the basis of the project no. N N306 316835

Main authors: Wojciech Wysota (Head of the project), Paweł Molewski, Włodzimierz Juśkiewicz

PhD students: Anna Groblewska, Włodzimierz Narloch, Karol Tylmann, Justyna Sobieraj

Co-workers: Wojciech Morawski, Dariusz Gałązka, Andrzej Latański


Ice streams
Ice streams, defined as zones of channelized rapid ice movement within an ice sheet, pose one of the most interesting study objects of present glacial geology. They are a few hundred km long and a few dozen km wide. The ice flow velocity in ice streams exceeds 400 m/year and is 7-8 times faster than that of the surrounding ice. In recent years convincing evidences of palaeo-ice streams within Pleistocene ice sheets have been delivered (see Patterson, 1997;  Jørgensen & Piotrowski, 2003; Boulton & Hagdorn, 2006; Jennings, 2006).

Criteria of identifying ice-streams
As a result of the research undertaken so far the basic geological criteria have been defined in order to identify the palaeo-ice streams within the extension of the last glaciation (Stokes & Clark, 2001). On the basis of the studies, which also included numerical models, the Vistula ice stream was suggested as one of the secondary palaeo-ice streams within the southern Baltic depression (Punnkari, 1993). The activity of the Vistula ice stream, however, has not been documented on the basis of the above criteria and the existing works are only of conceptual character (Marks, 2002; Morawski, 2009; Wysota et al., 2009).

The goal of the project and the study area
The goal of this research is to identify and analyse geospatially the geomorphological and sedimentological record of the Vistula ice stream lobe in central Poland to reproduce the subglacial processes against in bed conditions, determine the ice-flow pattern as well as delimit the parts of diverse ice velocity; to investigate the dynamics of the Vistula ice stream lobe in relation to the existing models and analogies to other palaeo- and modern ice streams.

 


The study methods
Three groups of methods were used in this study: GIS/geostatistic, field research and laboratory investigations. The geospatial analysis of geological and geomorphological data from published and archival sources as well as the results of the field and laboratory research remains the main study method. The field research is conducted in several key sites located within the Vistula ice lobe as well as in a few subareas of the glaciomarginal zone associated with the maximum limit of the ice advance. The investigations in the key sites include the following: sedimentological features of tills and their contact with the bed, measurements of directional elements, dispersal of erratics from tills, as well as geomorphological and morphometric analysis of landforms. Laboratory research include lithological and petrographic features of tills, micromorphology of tills and the determination of an age of intra-till deposits based on absolute dating.



Excepted research results
Solving the above research problems will enable the authors to reconstruct palaeoglaciology and palaeogeography of the Vistula ice stream lobe during the maximum extent of the last glaciation, such as characteristics of the ice movement and its bed conditions, spatial and temporal mobility of the ice stream, and its role in the distribution of ice masses in the southern margin of the Scandinavian ice sheet. Moreover, it will lead to solving a larger, still discussed issue, i.e. the one referring to the age of the maximum extent of the last Scandinavian ice sheet within the central Poland.



Zmieniony: czwartek, 30 września 2010 13:19