Naslov
The tectonic setting of the Promina Beds - A flexural foreland basin induced by a contrasting style of along strike deformation in the External Dinarides

Autori
Balling, Philipp ; Tomljenović, Bruno ; Ustaszewski, Kamil

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
XXI International Congress of the Carpathian Balkan Geological Association (CBGA), ABSTRACTS, Advances of Geology in southeast European mountain belts / Neubauer, Franz ; Brendel, Uwe ; Friedl, Gertrude - Sofija : Geologica Balcanica, Bulgarian Academy of Sciences, 2018, 203-203

ISBN
978-954-90223-7-7

Skup
XXI International Congress of the Carpathian Balkan Geological Association (CBGA)

Mjesto i datum
Salzburg, Austrija, 10.09.2018. - 13.09.2018

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
flexural foreland basin, Promina Beds, External Dinarides

Sažetak
The long-lasting convergence between the European and Adriatic plate led to the formation of the Dinar- ides fold and thrust belt. The Cretaceous deformation of the Internal Dinarides, composed by ophiolite-bar- ing nappes, is older than the mid Eocene deformation of the External Dinarides. The later consists mainly of shallow marine Mesozoic and Cenozoic carbonate platform rocks. Besides the overall younging trend of the start of the deformation from the internal to the external part, the Dinarides show a very prominent NW-SE “Dinaric” strike of the main folds and faults. However, a large-scale dextral strike-slip fault, the Split-Karlovac-Fault (SKF) striking N-S is interrupted this homogenous deformation pattern within the Ex¬ternal Dinarides. Within the most external part, the fault changed its strike to the “Dinaric” NW-SE strike and its kinematics turned to a pure top-SW thrusting. In close proximity to this change of fault kinematics, most of the heterogeneous 2 km thick mid-Eocene to late Oligocene sedimentary sequence is exposed - the Promina Beds. These beds are syn-tectonic and date the latest major deformation event within the Exter¬nal Dinarides and cover older Mesozoic and Cenozoic platform carbonate rocks in a progressive angular unconformity. Former sedimentological studies stated that the Promina Beds show an overall trend from deeper over shallow marine to fluvial depositional conditions, documenting the evolution from an under¬filled to an overfilled basin. The overall tectonic mechanism for the subsiding of the Promina Basin is a matter of debate, whether the accommodation space was created by a subsiding piggyback basin or in a flexural foreland basin setting. To validate one of the both tectonic settings, we have forward- and backward-modeled three balanced cross-sections on both sides of the SKF. Interestingly, the SKF marks a paleo-facies transition from a hiatus in the west to Permian evaporites in the east. The presence vs. absence of Permian evaporites led to areas of a contrasting style of deformation. The deformation in the western non-evaporitic segment of the SKF is characterized by a SW-vergent duplex system, which expands to the NW and is associated with a large- scale NE-vergent back thrust. In contrast, within the eastern segment the evaporites served as a main de¬tachment, which is used to tectonically double the entire carbonate platform by a SW-vergent nappe stack. Our results show, that the complex and contrasting hinterland deformation is related partly to the pres-ence of evaporites, leading to a nappe stack in the eastern segment, which produced a lithosphere flexure and enough subsidence. This favours the flexural foreland basin hypothesis for the origin of the Promina Basin, because most of the present-day outcropping sediments can be solely found in a close proximity to this eastern nappe stack. The Promina Beds solely contain carbonate platform rocks, proving that the catch¬ment did not substantial changed throughout time.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA