Projects / Programmes
Mesozoic stratigraphy and tectonic evolution of the Southern Alps in Slovenia
| Code |
Science |
Field |
Subfield |
| 1.06.06 |
Natural sciences and mathematics |
Geology |
Regional geology |
| Code |
Science |
Field |
| P005 |
Natural sciences and mathematics |
Geology, physical geography |
| Code |
Science |
Field |
| 1.05 |
Natural Sciences |
Earth and related Environmental sciences |
Southern Alps, Dinarides, stratigraphy, structural geology, geological mapping
Researchers (6)
Organisations (1)
Abstract
The study area in NW Slovenia is part of a more than 300 km long transition zone between the Dinarides and the Southern Alps that extends from the Dolomites in northern Italy to Mt. Medvednica in northern Croatia. This central segment of the transition zone is crucial to understand the interference tectonics caused by overlap of two orogenic belts. The area is relatively well known stratigraphically but remains structurally largely unexplored. Stratigraphic research revealed a complex Mesozoic paleotopography of a fault-bounded submarine high (the Julian High) surrounded by deeper basins. The existing tectonic maps, on the other hand, are extremely generalized, do not reflect the determined pre-orogenic paleotopography and do not provide a clear separation of Dinaric and South-Alpine structures.
In the proposed project we will concentrate on geological and structural mapping in the Julian Alps and the Southern Karavanke Mountains. The aim of the project is 1) to summarize the relevant data on Lower Triassic to end-Cretaceous stratigraphy, 2) to present structural evidence for the existence of several superposed nappes that were emplaced during the Dinaric thrusting phase, and 3) to investigate the style and pattern of younger structures.
Specific questions that will be addressed are the following:
1) What was the configuration of the Mesozoic Adriatic continental margin preserved in the study area? What was the size and what is the likely 3D reconstruction of the Julian High?
2) What is the most probable nappe-pile restoration after the Dinaric (post-Maastrichtian) thrusting event? What was the sense of movement and what are the age constraints for this event?
3) How and when did the second, i.e. South-Alpine phase of shortening modify the initial nappe stack? What was the maximum stress direction and to which extent was this deformation controlled by the dextral transpressional shear? Which pre-existing structures or stratigraphic non-homogeneities were the predominant zones of weakness? Is it possible to interpret the overall dish-like shape of the Julian Alps as a South-Alpine pop-up structure?
4) How was the pattern of subsequent (Miocene) normal faults related to the contraction features of the preceding phase and what was the main cause of extension?
The final goal of the project is to construct an up-to-date tectonic map of the area and to restore the polyphase deformation history through the Paleogene and early Neogene. The data will be interpreted in a regional framework of the Alpine-Dinaric-Carpathian orogenic system and will contribute to further development of paleogeographic and tectonic models on a regional scale.
Significance for science
The results will be original and valuable because systematic structural investigations have so far not been carried out in NW Slovenia. The preservation and exposure of folds and thrust faults in the proposed study area are excellent and thus ideal to obtain relevant data on the complex tectonic history. Integrated stratigraphic and structural research in this area may help not only to reveal the deformation history of the broader region but also to better understand the poly-phase compressional evolution of interference zones in general. A special emphasis will be placed on investigating the relationships between the structural evolution of the orogenic belt, and the pre-existing (inherited) structural elements and rheology of the involved lithostratigraphic units. We think that it is about high time to synthesise the wealth of the recently obtained stratigraphic results and to complement them with structural field measurements in order to propose a meaningful and up-to-date tectonic reconstruction that would be of interest to a wide community of geologists interested in regional geology of the Alpine–Dinaric–Carpathian orogenic system.
The results will have further applicability in other geological disciplines (e.g. in assessing seismic, landslide and rock-fall hazards). They will be also applicable for public promotion of geology and of the Slovenian natural heritage. The sites to investigate are located in an area with highly developed mountain tourism (including the Triglav National Park) and will be evaluated in terms of conservation, protection and educational value.
Significance for the country
The results will be original and valuable because systematic structural investigations have so far not been carried out in NW Slovenia. The preservation and exposure of folds and thrust faults in the proposed study area are excellent and thus ideal to obtain relevant data on the complex tectonic history. Integrated stratigraphic and structural research in this area may help not only to reveal the deformation history of the broader region but also to better understand the poly-phase compressional evolution of interference zones in general. A special emphasis will be placed on investigating the relationships between the structural evolution of the orogenic belt, and the pre-existing (inherited) structural elements and rheology of the involved lithostratigraphic units. We think that it is about high time to synthesise the wealth of the recently obtained stratigraphic results and to complement them with structural field measurements in order to propose a meaningful and up-to-date tectonic reconstruction that would be of interest to a wide community of geologists interested in regional geology of the Alpine–Dinaric–Carpathian orogenic system.
The results will have further applicability in other geological disciplines (e.g. in assessing seismic, landslide and rock-fall hazards). They will be also applicable for public promotion of geology and of the Slovenian natural heritage. The sites to investigate are located in an area with highly developed mountain tourism (including the Triglav National Park) and will be evaluated in terms of conservation, protection and educational value.
Most important scientific results
Interim report
Most important socioeconomically and culturally relevant results
