Naslov
Along-strike shortening variations across the external Dinarides quantified by means of balanced cross-sections

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

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

Izvornik
TSK16 Abstract Bonn / - , 2016, 11-11

Skup
16th Symposium on Tectonics, Structural Geology and Crystalline Geology, TSK 16

Mjesto i datum
Bonn, Njemačka, 02.03.2016. - 06.03.2016

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Balanced cross-section, Paleogene shortening, External Dinarides

Sažetak
The long-lasting convergence between the European, African and Adriatic Plates led to the deformation of the Dinarides fold and thrust belt. This orogen is subdivided into the internal and external Dinarides. The internal part is composed by composite ophiolitic nappes, whereas the external part consists of several thrust sheets of mainly Mesozoic to Paleogene shallow marine Adriatic Carbonate Platform rocks. The presence of Mid-Eocene to Mid-Miocene syntectonic deposits defines the time interval of SW directed folding and thrusting. Here Triassic and Late Cretaceous evaporitic intercalations serve as main detachment horizons in the external Dinarides, resulting in a NW-SE strike, which can be traced from Slovenia to Albania. However, the exact amount of total shortening and its Neogene component is unknown. To tackle this issue we balanced two unpublished cross-sections across external Dinarides. Furthermore, we investigated several Miocene wedge-top basins with respect to their substratum. These restricted intra-montane basins were filled with up to 500 m of lacustrine limestones. Field observations show that these basins are not fault bounded and passively uplifted by much deeper faults. This is supported by the analysis of longitudinal river profiles, which show that major knickpoints in this area are immobile and are hence rather related to erosional contrast between different lithologies. This, in turn, implies that the basin boundaries underwent insignificant deformation. Our balanced sections strongly support the assumption that the total amount of shortening within the study area is highly variable alongstrike. In the northern profile we assessed a total shortening of ~60 km (38%), whereas in the southern profile a minimum shortening of ~130 km (88%) was estimated. The high variation of shortening amounts is strongly affected by the presence of a largescale dextral transpressive strike-slip fault, the Split-Karlovac Fault. This fault also seems to actively accommodate seismogenic strain. This is suggested by the pronounced seismic moment release that spatially coincides with the SE end of the Split-Karlovac Fault. The fact that the great majority of earthquakes along the southern profile show reverse faulting mechanisms, implies that the strain field remained unchanged since the onset of folding and thrusting in Paleogene times.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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