The project includes a number of research activities focussed in the understanding of the role of supply in building the sequence architecture using the case-study of the Panonian Basin and in identifying the specificity of sequence stratigraphy in deep lakes as compared to the classical sequence stratigraphy models.


These activities are grouped in three interrelated MODULES:


MODULE 1 (University of Texas at Austin, Utrecht University)



This physical experiment is run in sedimentological laboratory at the University of Utrecht. The concept of the experiment is to test hypotheses regarding the relative importance of sediment supply and base-level fall in the generation of incised versus non-incised configurations at the shelf edge, in the generation of turbidity currents on the shelf margin. The experiment is supervised by Ron Steel (University of Texas, Austin), George Postma (University of Utrecht) and Piret Plink-Bjorklund (University of Gothenburg).

The key aspect of the work is to see if we can, with physical experiments, dampen the tendency for incision in river channels at the shelf edge, by increasing sediment/water ratio in the shelf edge discharge and/or suspended sediment concentration in this discharge. The likelihood that this happens has been already suggested by numerical experiments, and by field observations on Eocene shelf margins on Spitsbergen. The importance of the work is that it will open for alternative scenarios to the conventional belief that incision or lack of incision at the shelf edge is due primarily to magnitude of sea-level fall at and below the shelf edge.



MODULE 2 (Eötvös University Budapest, University of Texas at Austin)



The high level of existing work on sequence stratigraphy stratigraphy analysis in the Pannonian basin-fill provides an excellent natural laboratory for testing the applicability of the results from the analogue experiments in Utrecht. In general, the possible changes on sequence pattern associated with the changes from marine to fresh water conditions within the Pannonian basin are examined. More specifically, in the interpretation of the Pannonian clinoform details, the following three aspects is weighted:


1. Application of the Utrecht experimental results in terms of whether the lake-basin turbidites are generating shelf-break-attached sheets (little or no incision) or are by-passing the slope in channels/canyons to generate basin-floor fans/lobes.


2. A general re-consideration of the sequence stratigraphic methodology as applied to deep-lake basins. It is known that sediment supply and base level are much more closely tied to each other in lake basins than in open-marine basins, and that climate is more directly affecting lakes than it does the open sea. This is likely to have an important effect on the development of systems tracts in the lake basin. In the sediment supply model, close attention will be paid to when sediment discharge is likely to have been maximum (during early lake-level rise?) and where waxing and waning of discharge occurs in the base-level cycle. It is also investigated how realistic it is to have a well-developed highstand systems tract in lake basins (when lake level is highest and initially falling, fluvial input may be lowest).


3. Construction of a general sequence-stratigraphic model for deep-lake basins, by using 1) and 2) above, together with an analysis of the Pannonian clinoform architectures and trajectories. In building the general model an attempt is made to incorporate literature data and ideas from other areas such as the Caspian, from Laramide lake basins in USA, and from Chinese basins.



MODULE 3 (Eötvös University Budapest)



This module is designed as a complement to MODULE 2, but also as an introduction to a project which may be further developed in the next future. The aim is the understanding of the recent and sub-recent conditions of climate, hinterland drainage, changes in supply, rate of aggradation, and fluvial regime prevailing at the Pannonian basin with particular focus at the Tisza alluvial plain. The recent and sub-recent picture of the observable conditions may be used as analogue to other time slices from older sequences analyzed in MODULE 2.


In addition, the study contributes to the reconstruction of the paleogeographic conditions during the latest stage filling up of the Pannonian basin system, and illustrates the transition from aggrading to degrading conditions during late Quaternary to Holocene times.


The work is principally based on literature analysis, making also use of the detailed available data and knowledge so far acquired by our Institute on the Tisza river system.