Sediment infill of the Middle Triassic half-graben below Mt. Vernar in the Julian Alps, Slovenia

A sediment infill of a small, late Anisian–earliest Ladinian half-graben, sealed by massive limestone of the Schlern Formation is exposed on the northeastern slopes of Mt. Vernar in the eastern Julian Alps, Slovenia. The pre-rift base of the succession is formed by a chaotic mixture of massive limestone and limestone breccia of the Anisian platform. Sedimentation in the half-graben started with a 20 m thick thinly bedded pink nodular limestone which is informally named here as the Vernar member. It consists of microbial carbonate and was probably deposited within the photic zone. The Vernar member is overlain by poorly sorted polymict breccias of the Uggowitz Breccia Formation which reaches a thickness of at least 150 m, but pinches out rapidly towards the SE graben margin, reflecting the highly asymmetric basin geometry. Individual beds of breccia represent successive debris flow deposits. The Uggowitz Breccia Formation is followed by a few metres of sandstone and sandy limestone of the Buchenstein Formation. The limestone contains abundant grains of shallow marine origin and terrestrial plant fragments. The overlying post-rift Schlern Formation consists of crudely bedded and massive limestone, covering the graben. The consistent NE-SW strike of the graben-bounding faults and of the smallscale conjugate normal faults observed in the Uggowitz Breccia Formation suggests that the half-graben originated from NW-SE directed extension

Sedimentacijsko okolje srednjetriasne Strelovške formacije na Raduhi v Kamniško–Savinjskih Alpah, severna Slovenija

The Raduha section represents a continuation of the research of the Anisian Strelovec Formation in the Kamnik-Savinja Alps. The Strelovec Formation was deposited during the Anisian on a drowned section of the Serla Dolomite carbonate platform in a restricted probably outer ramp environment associated with an intraplatform basin. The base of the section is represented by dolostone breccia containing angular carbonate lithoclasts of shallow-marine origin. This is followed by alternations of laminated and homogenous hemipelagic limestones deposited in a restricted and anoxic environment. Hemipelagic sedimentation was occasionally interrupted by clay input and deposition of sediments from gravity mass flows. Slow filling of the basin lead to a gradual cessation of anoxic conditions and sedimentation of bedded shallow-marine limestones. After shallow water conditions were established, bioclastic dolostone of the Contrin Formation was deposited.Profil Raduha predstavlja nadaljevanje raziskav anizijske Strelovške formacije v Kamniško-Savinjskih Alpah. V aniziju se je na potopljenem delu karbonatne platforme formiral intraplatformni bazen, v katerem je prišlo do sedimentacije Strelovške formacije na verjetno zunanjem delu karbonatne rampe. Profil se prične z dolomitno brečo s klasti spodaj ležeče anizijske karbonatne platforme. Sledi sedimentacija hemipelagičnih plastnatih laminiranih ter homogenih apnencev v hidrodinamično mirnem in anoksičnem okolju. Umirjene pogoje sedimentacije so občasno prekinili gravitacijski tokovi (sinsedimentni zdrsi in turbiditi), ki so vnesli droben klastični material s kopnega. S počasnim zasipavanjem bazenskega okolja pride do postopne prekinitve anoksičnih pogojev ter sedimentacije plastnatih plitvovodnih apnencev, kar nakazuje na popolno zapolnitev intraplatformnega bazena. Sledi sedimentacija bioklastičnega dolomita zgornjeanizijske Contrinske formacije

Tectonic contact beetwen Paleozoic and Triassic rocks south of Podolševa (Slovenia)

Tectonic contact between Paleozoic and Triassic rocks south of Podolševa, which passes prominent cliffs over the left bank of Savinja river (Klemenča peč, Jamnikova peč, Golerjeva peč, Strevčeva peč and Huda peč), is on the basis of the new mapping a steep fault, dipping to the north. In the last phase, the fault was dextral strike – slip active, before was probably reverse, and can represent accompanying structure of Periadriatic lineament. It was under transpresive tectonic regime and complies with model of positive flower structure.We named it Podol{evski prelom (Podol{eva fault)

Carnian bauxite horizon on the Kopitov grič near Borovnica (Slovenia) – is there a »forgotten« stratigraphic gap in its footwall?

Beds underlying the Carnian bauxite on the Kopitov gri~ (Slovenia) are by the author’s opinion not Carnian (Cordevolian), but Ladinian age. The considerable stratigraphical gap is presented between Carnian clastic rocks and underlying limestones and dolomites. Bauxite is result of the weathering during the emersion

Problems of the “Cordevolian Limestone and Dolomite” in the Slovenian part of the Southern Alps

Stratigraphic position and age of the so called Cordevolian limestone and dolomite in the Slovenian part of the Southern Alps (figure 1) is a long lasting problem. Its name originates from the (somewhere abandoned) Cordevolian substage (Lower Carnian). Limestone and dolomite both correspond to the Cassian dolomite from the Italian Southern Alps. Platform type of limestone and dolomite, which could be genetic and time equivalent with the Ladinian Schlern (Scilliar) dolomite, is unknown in Slovenia. In the NE part of the Kamnik–Savinja Alps, the Korošica formation (Upper Ladinian) overlies platform limestone and dolomite of the Ojstrica Formation (Ladinian). Diplopora annulata is also present in the Ojstrica formation. Various Ladinian rocks in the Julian Alps and Southern Karavanke are mainly of the Lover Ladinian age, whereas the overlying massive limestone and dolomite (“Cordevolian limestone and dolomite”) are partially of the Ladinian and partially of the Carnian age. There are no Upper Ladinian “Wengen” beds in the carbonate massive, so it is impossible to draw a time line between the Ladinian and the Carnian stages. We can therefore conclude, that litological boundaries do not coincide with the chronostratigraphic ones

Shallow intrusive volcanic rocks on Mt. Raduha, Savinja-Kamnik Alps, Northern Slovenia

Volcanic rocks occurring in Ladinian (?) marls, interstratified with limestone (Solčava beds), at Grohat Alpine Meadow and Lipni plaz, Mt. Raduha, are shallow intrusives bodies with porphyric structure, and basaltic andesitic, acid andesitic and dacitic composition.Abundance of major oxides and trace elements in the studied rocks is similar to those observed in the Tertiary Smrekovec volcanic rocks suggesting contemporaneous formation and close genetic relationship

Sesljanski prelom in sesljanska upogibna cona

The Sistiana Fault is an alleged disjunctive deformation of Microadria in the sea bottom of the Gulf of Trieste. Onshore, it is visible only in the Sistiana Bay, but towards the northeast it soon pinches-out, in structural-geometric terms it diminishes soon after the crossing of the thrust boundary of the Dinarides, or the Istrian-Friuli Underthrustig Zone, respectively. Further to the northeast, only the bending zone is developed in the External Dinarides, which stretches all the way from the Sistiana Bay to the Idrija-Žiri area. We named it the Sistiana Bending Zone. Its direction can be determined based on geological maps and is around 60°, so we conclude that the Sistiana Fault should extend approximately in this direction. In the bending zone, the Trieste-Komen Anticlinorium, the Vipava Synclinorium, the Trnovo Nappe opposite to the Hrušica Nappe and the Raša and Idrija Faults are laterally bent. The size of the bend is the largest in the Sistiana Bay, and in the east-northeast direction it decreases linearly. The general geological circumstances suggest that the Sistiana Fault has not been recently active.Sesljanski prelom je domnevna disjunktivna deformacija Mikroadrije v podmorju Tržaškega zaliva. Na površju je viden le v Sesljanskem zalivu, vendar se proti severovzhodu kmalu izklini, v strukturno-geometrijskem smislu izzveni kmalu zatem, ko preseka narivno mejo Dinaridov, oziroma istrsko-furlansko podrivno cono. Naprej proti severovzhodu je v Zunanjih Dinaridih razvita le še upogibna cona, ki se vleče vse od Sesljanskega zaliva do idrijsko-žirovskega ozemlja. Imenujemo jo sesljanska upogibna cona. Njena smer je določljiva na podlagi podatkov geoloških kart in znaša okoli 60°, zato sklepamo, da naj bi Sesljanski prelom potekal približno v tej smeri. V upogibni coni so bočno upognjeni Tržaško-Komenski antiklinorij, Vipavski sinklinorij, Trnovski pokrov nasproti Hrušiškemu pokrovu ter Raški in Idrijski prelom. Velikost upogiba je največja v Sesljanskem zalivu, proti vzhodu-severovzhodu pa se linearno manjša. Iz splošne geološke slike izhaja domneva, da Sesljanski prelom recentno ni aktiven

Anisian Strelovec Formation in the Robanov kot, Savinja Alps (Northern Slovenia)

A detailed sedimentological features of the Slatinski plaz section with a transition from the deep-water Anisian (Illyrian) Strelovec Formation to the Ladinian shallow-water Contrin Formation have been presented. The Strelovec Formation is divided into fie different lithostratigraphic units that are characterised by dark hemipelagic and pelagic thin-bedded limestones and dolomitic mudstones that are frequently intercalated with deposits of gravitymass flws, slump and slide to fie-grained low-density turbidity origin. The Strelovec Formation was deposited in a hydrodynamically quiet, pelagic deeper-water anoxic environment, most probably on a gentle platform slope. In the upper part of the formation, the presence of olistolith blocks of shallow-water limestones indicates the closing of the prograding shallow-water platform wedge. Massive dolostones of Unit 6 mark the complete filing of the basin and the beginning of the shallow-water sedimentation of the Contrin Formation in the Early Ladinian

The bases for understanding of the NW Dinarides and Istria Peninsula tectonics

Thrust structure of the northeastern part of the External Dinarides is depended upon paleogeography of the Adriatic–Dinaric Mesozoic Carbonate Platform, which was in the southeast (in the recent position) composed of Dinaric and Adriatic segment with intermediate Budva Trough. In the northwest in the area of the present Slovenia, it represents uniform platform. In the northwestern continuation of the Budva Trough, shallow halftrough formed and more to the west, shallow Friuli Paleogene Basin came in to being, which separated so called Friuli Carbonate Platform from the central part of the carbonate platform. Area of Istria was separated from Adriatic segment with Kvarner Fault, originated already in the Mesozoic.External Dinaric Thrust Belt formed in the finalphaseoftheDinaridesoverthrusting.ItoriginatedfromDinaricsegment of the Mesozoic Carbonate Platform at the end of the Eocene and was thrusted on the Adriatic segment of the Mesozoic Carbonate Platform. Whole process also triggered formation of the External Dinaric Imbricate Belt with Thrust Front of the External Dinarides against Adriatic-Apulian Foreland. Later also represents rigid indenter of the Adria Lithospheric Microplate (“Adria”), and External Dinaric Imbricate Belt represents its deformed margin, therefore we place it to the rigid indenter.Segmentation of the “Adria” occurred in the Miocene or later. It roughly disintegrated in the Padan and Adriatic part along Kvarner Fault. During rotation of the Padan part in the counter clockwise sense, the corner part, representing Istria Peninsula, rotated and underthrusted towards northeast under External Dinarides. As a result, Istria-Friuli Underthrust Zone formed, structurally conditioned with the position of the Friuli Paleogene Basin, and vast Istria Pushed Area between Southern Alps, Velebit Mts. and Želimlje Fault. This process is still active recently.During Istria underthrusting and pushing in the northwest direction, Ra{a Fault and Thrust Front of the External Dinaric Thrust Belt bended, and as a consequence, strike-slip movements along those planes were hindered. From the tip of the Kvarner Bay towards Idrija and Ravne Faults in the Upper So~a Valley, conditions for formation of the en echalon strike-slip belt were set up. The strike-slip belt is definedwithsegmentoftheRa{a Fault southeast from Ilirska Bistrica, seismically active area between Ilirska Bistrica – Hru{evje stretch, Vipava Fault, Predjama Fault and northwestern part of the Idrija and Ravne Fault. Therefore we postulate, that a segment of the External Dinaric Thrust Belt Front and shear boundary between the tip of Kvarner Bay and Upper So~a Valley, with extended branches of the Idrija and Ravne Faults, represents new attached block of the Adria Microplate rigid indenter edge