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The late Eocene to Recent dynamics of the NW External Dinarides in Slovenia are described. The study is focused on the orogen-parallel NW-SE striking family of faults, which represent the main source of seismic hazard in the NW External Dinarides today. Approximately 1700 faultslip datasets were collected at 70 locations and used for palaeostress analysis. Structural relationships observed in the field, allowed the construction of a relative chronology between the documented fault and shear joint sets, facilitating the reconstruction of their kinematic evolution and the chronology of palaeostress phases. Four post-Palaeocene stress tensor groups are documented corresponding to four distinct tectonic phases. The first phase is marked by NE-SW directed compression attributed to Late Eocene top-to-SW thrusting of External Dinarides. The second phase is characterized by NE-SW oriented tension, documented by normal slips recorded on NW-SE striking faults. This tension is interpreted as an expression of the Early to Middle Miocene back-arc extension in the Pannonian basin system that also affected the studied part of the External Dinarides. The third phase is manifested by approximately E-W oriented compression with approximately N-S oriented tension in a strike-slip stress regime, causing sinistral reactivation of NW-SE trending faults. Geodynamically, this phase can be correlated with the Late Miocene short pulse of E-W directed compression, documented in parts of the Pannonian basin system. The youngest phase is characterized by approximately N-S oriented compression and approximately E-W oriented tension in a strike-slip stress regime, which caused dextral reactivation of NW-SE striking faults. This phase correlates with the recent inversive/transpressive phase, well-established from seismological data.

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The I{ka alluvial fan exdtends towards the Ljubljana moor.Vr{aj I{ke sega {e dale~ proti Ljubljanskemu barju. JURIJ SENEGA^NIKLea @ibret, Gorazd @ibret, Use of geomorphological indicators for the detection of active faults in southern part of Ljubljana moor, Slovenia ABSTRACT: In order to detect recently tectonically active faults, Stream Length-gradient (SL) index and a newly developed method of river gradient analysis were made for three rivers. Two methods were used on the southern part of Ljubljana moor, where rivers cross dextral (right-lateral) faults with Dinaric orientation (NW-SE). Watercourse profiles were analysed first, using a »classic«, well established method of SL index. However, this method didn't yield useful results since almost no variability in SL indexes were observed. Additionally, a second newly developed method pointed on the anomalies, which might correspond to the areas of active surface uplift and subsidence as a consequence of active tectonic movements. We compared determined anomalies with the fault lines plotted on the Basic geological map 1 : 100.000 and with the data of radar measurements of vertical movements by PSInSAR method. In this way five potentially active faults, areas of contraction and areas of extension were determined. The results of this research can be used as complementary information for the construction of tectonic model of Ljubljana field and Ljubljana moor.

The aim of this study was to determine properties of the tectonic contact between Permian/Mesozoic limestones and less competent Miocene clastites on the northeastern foothill of the Boč Mt. Because fault planes significantly mark the relief, this contact was studied by a detailed structural mapping, which showed that the Boč Mt. is limited by subvertical faults in its northeastern part. To ensure that mapped subvertical contact is compatible with regional geodynamics of the area, additionally paleostress analysis of fault-slip data was performed. Four individual paleostress tensor groups were documented in a wider Boč area and compared by published structural data from the border zone between Alps, Dinarides and Pannonian Basin. The oldest paleostress tensor group (Phase 1) is likely of Lower and Middle Miocene age and indicates SW-NE extension accommodated by W-E to WNW-ESE striking normal faults. Phase 2 can be correlated with Middle to Late Miocene NW-SE to WNW-ESE directed extension accommodated by NNE-SSW striking normal faults. Phase 3 is correlated with Late Miocene W-E directed contraction accommodated by N-S striking sinistral faults and NNE-SSW to NE-SW striking dextral faults. The youngest paleostress tensor group (Phase 4) fits well with Pliocene to Quaternary NNW-SSE to N-S directed contraction accommodated by NW-SE to W-E striking dextral faults and NE-SW striking reverse faults. Since the documented paleostress phases fits well with the geodynamic processes of the Alps-Dinarides-Carpathians territory the subvertical border in the northeastern part of Boč Mt. seems to be an acceptable structural solution. The study is important because the study area is located at interaction zone between two major Alpine fault systems: the Periadriatic and the Lavanttal faults. IzvlečekGlavni namen raziskave je bil ugotoviti značaj tektonskega kontakta, ki poteka vzdolž severovzhodnega pobočja Boča v coni Periadriatskega in Labotskega preloma. Ker gre za kontakt med permskimi/mezozojskimi apnenci in manj kompetentnimi miocenskimi klastiti, prelomne ploskve, ki predstavljajo kontakt enot, v reliefu značilno izstopajo. Zato je raziskava temeljila na natančnem strukturnem kartiranju območja, ki je pokazalo, da je Boč na severovzhodnem delu omejen s subvertikalnimi prelomi. Rezultati terenskega kartiranja se ujemajo z regionalno geodinamiko območja, ki je bila preverjena s paleonapetostno analizo opazovanih zdrsov ob prelomnih ploskvah. V širši okolici Boča so bile dokumentirane štiri skupine paleonapetostnih tenzorjev, ki so bile nato primerjane z objavljenimi strukturnimi podatki iz prehodnega območja med Alpami, Dinaridi in Panonskim bazenom. Najstarejša faza (Faza 1) je najverjetneje spodnje do srednjemiocenske starosti in odraža ekstenzijo ozemlja v smeri SW-NE, ki jo vidimo na normalnih prelomih s slemenitvijo W-E do WNW-ESE. Fazo 2 lahko primerjamo s srednje do zgornjemiocensko ekstenzijo ozemlja v smeri NW-SE do WNW-ESE, ki se odraža na normalnih prelomih s slemenitvijo NNE-SSW. Faza 3 je primerljiva ...