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Sedimentary and stratigraphic developments with tectonic settings of Paleogene and Neogene sediments in individual Central Europe basins.

Oolitic and oncoidal rocks, microfacies, depositional environments and their stratigraphic ranges in Sloveniaare subjects of this article. Various types of calcareous ooids are present in the Upper Carboniferous, Permian andTertiary (Paleocene and Miocene) beds and specially at many levels in an up to 6000 meters thick statigraphic successionof the Mesozoic age. Sedimentological investigations have been carried out specially in the Triassic andJurassic beds. The ooids occurring in the shallow-water and intertidal carbonate environment have been groupedinto seven types and oncoids into four types. Oncoids are rather more aboundant in Carnian and Norian/Rhaetianage. Late dolomitization of some oolitic beds is next to cementation the main diagenetic feature.

The renewed deposition in the Palaeogene and the oldest part of the non-interrupted Palaeocene succession is characterized by the presence of Decastronema barattoloi (DE CASTRO), cyanobacterial tubes originally described in the Apennines. The reinterpretation of limestones from several sections located in the Kras region (NW part of the AdCP: Basovizza, Dolenja vas, Sopada, ?ebulovica) confi rmed the presence of these microfossils in peritidal sediments of Danian age (SBZ 1). The Cuisian (Late Lower Eocene) sediments, from eastern Istria (Brnjci section), Cres Island (Koroma?na Cove section) and Ravni kotari (Benkovac–Korlat section) contain individuals of this species in great numbers. The cyanobacterial tubes are scattered in laminated, fi ne grained mudstones and wackestones, immediately above the Cretaceous sediments (occasionally above bauxites or breccias). The Decastronema-bearing sediments pass upward into the Foraminiferal limestones of Cuisian age (SBZ 11, based on conical agglutinated foraminifera and alveolinids), allowing the age determination of the cyanobacterial remnants. The Palaeocene specimens are minute (up to about 180 ?m long), thick walled tubes that occur with the index fossil Bangiana hanseni DROBNE. The Eocene forms accompanied by ostracods, pelecypods, and miliolid and rotaliid foraminifera are segmented tubes, up to 400 mm long and usually thin walled.

This contribution deals with geological setting of Mt. Kobla which is situated in the central part of the Bohinj ridge, and brings a review of the previous geological studies in the area.The first detailed studies are closely related to a 6334 m long Bohinjska Bistrica–Podbrdo railway tunnel which was opened in 1906. The tunnel is constructed just under the peak of Mt. Kobla and encompasses 8 lithological members. The second period of intensive geological studies is related to elaboration of the Basic Geological Map, scale 1:100.000, Sheet Tolmin that were carried out from 1969–1987. During this time, Middle Triassic to Late Cretaceous existence of Slovenian Basin and two platforms in western Slovenia was established. In the past decade geological studies in the area have been focused on detailed stratigraphy and lithology. The analysis of conodont assemblages and foraminifers indicates that a part of limestone classified in Basic Geological Map as Lower Jurassicare actually of the Upper Triassic age.Jurassic sediments in Mt. Kobla were settled in deep-marine environment of the Slovenian Basin. Limestone breccias and calcarenites were transported by gravitational currents from the shelf edge to the slope and to the basin. In Lower Jurassic calcarenite with abundant reworked ooids and crinoids occur.

The transition of Maastrichtian to Danian in SW Slovenia was studied in two shallow marine carbonate successions. Apart from the extinction of some biota, the K/T boundary is reflected also in carbonate isotopic composition and in geochemistry. The K/T boundary is characterized by 20 cm to 1 m thick sedimentary breccia of intertidal origin. Extreme depletion in the δ 13 C content (up to − 8‰) was found in Dolenja Vas section just at this boundary. It related to global climatic changes caused by impact of extraterrestrial body followed by the destruction and combustion of terrestrial plants. Slight enrichment in δ 13 C content (up to 2‰) is evident at Danian/Selandian boundary too.

Sediment cores collected in eutrophic subalpine Lake Bled (NW Slovenia) were analyzed sedimentologically in terms of grain size, mineralogy and sedimentation rates, and geochemically in terms of metals and nutrients. Surficial sediment is composed of dark gyttya type clayey silt with 5%–10% of organic matter. The sediment below is fine laminated and composed of homogenous silt and clayey silt: Mineralogically, low-Mg calcite prevails, followed by dolomite, quartz, partially of diatomaceous origin, and feldspar. Clay minerals are composed of muscovite/illite and chlorite. Authigenic minerals are pyrite and ‘lake chalk’ (low-Mg calcite). Lake sediment is especially polluted by Pb, Zn and P. Higher contents were found in the northwestern and eastern parts due to the particle input by local inflows. Increasing eutrophication and pollution, indicated by Cd, Cu, V, Cr, Co and total N and P enrichment in the top layers of the cores, started almost 100 years B.P., and especially 50 years ago.

In the year 2004, a deep borehole MET/04 east of Metlika in Bela Krajina was drilled. It reached the depth of 841 meters. The aim of drilling was to catch thermal water that would be used for touristical purposes. The area where the borehole is located belongsto the transitional zone of the External to the Internal Dinarides. The first ones are characterized mainly by shallow water carbonate rocks of Mesozoic age, while the other ones are composed mainly of deep water clastic rocks also of Mesozoic age. Structurally,this zone consists of a series of the Dinaric, NW-SE oriented, thrusts along which the Internal Dinarides are thrusted over the External ones. The bore hole itself is located in the flysch sequence of Upper Cretaceous age that is deposed transgressivelly onto theUpper Jurassic limestone. The flysch, that is composed of conglomerate, breccia, calcarenite and marl, is drilled to 182,5 m of depth. Further, to the 275 of depth, there follow Lower Cretaceous limestones, that belong either to large olistolitic blocks in the base of the flysch series or to a tectonic block of the imbricated structure. To the bottom of the borehole, there follow mainly ref and perireefal limestones of Upper Jurassic age. The upper part of these is determined to be of Upper Malmian age, since the lower part couldbelong to Lower Malmian. In the borehole, two water bearing zones were determined. The first one is in the interval from 92,5 to 184, and the second one in the interval from 220 to 355 meters at the depth.

A Middle-Aptian (zone of Palorbitolina lenticularis) „patch reef“ of about 40 m maximum thickness with marked morphology was analyzed at the Sabotin Mountain near Nova Gorica. It is developed above an basal unit of superficial oolites within lagoonal sediments and is overlain by shallow subtidal to intertidal sediments which reveal short time periodically subaerial exposure and early diagenetic freshwater influxes (birds eyes, vadose silt, characeans). Above these sediments within the zone of Salpingoporella dinarica finebedded to platy, laminated bituminous limestones occur.The central part of the reef structure reveals an alternation of individual lenses of Lithocodium-boundstones and of rudist-beds (up to 4 m thickness) which are separated by coarse- to medium-grained, moderately to poorly sorted bioclastic sands. These faciestypes show also lateral interfingering and are concentrated in the central part of the buildup where the greatest thickness can be observed and where packstones, grainstones and boundstones prevail. The neighbouring lagoonal sediments which consist of mudstonesand wackestones predominantly were analyzed in the so-called Sabotin-standardprofile which is located north of the patch reef at a lateral distance of about 300 m.Three vertical profiles (A = 90 m, B = 100 m, C = 64 m thickness) were analyzed. The middle profile B of greatest thickness is taken as reference profile and documents best the vertical facies development within the patch reef directly overlying a basal unit of peloidal packstones with superficial ooids. The patch reef itself is characterized by the faunal associations within the unit rich in Lithocodium and rudists. It is overlain by a subtidal unit of peloidal mudstones with very minor biogenic allochems. An intertidal unit above rich in birds-eyes and vadose silt is followed by fine-laminated black shales which are covering the general seqeunce of interfingering patch-reef – lagoonal sediments.Using different time lines (marker horizons) for correlation it can be shown that already very early differential compaction of fine-grained uncemented sediments in comparison to the core area of the patch reef is of great importance.The greater thickness of the patch reef itself is caused by an intensive early diagenetic marine phreatic cementation within the core zone and by the early fixing of sediment by Lithocodium aggregatum (syn. Bacinella irregularis) resulting in a greater resistivity against compaction. Furthermore a lagoonal side and an more open marine side of the patch reef can be determined. Lithocodium aggregatum is the main constructing organism within the buildup investigated, beginning with the incrustation of varying substrates and biogenic particles. Finally, a dense network of encrustation-sequences is formed interfingering with the general sedimentary textures intensively and resulting in larger „biogeniccemented“ patches within the sediment.The correlation of the three profiles A, B, and C allows to reveal the history of differential compaction of the associated lagoonal sediments in comparison to the more massive patch reef limestones. It becomes obvious that the main compaction must have occurred within the time span of about 50 m sediment-deposition overlying the patch reef. Differential compaction resulted in differences in thickness of about 10 m from the patch reef (profile B) to the more lagoonal influenced sediments (profile A) within a lateral distance of about 50 m.

Two sections located in the northwestern part of the Palaeogene Adriatic carbonate platform (PgAdCP) were measured and sampled to document the complexity of changes at the Palaeocene–Eocene boundary. Carbon and oxygen isotope records in combination with a detailed study of larger benthic foraminifera (LBF) are used to describe the turnover of foraminifera and to refine the shallow benthic zonation scheme.

Microbialite units are commonly found within the Mesozoic–Tertiary carbonate succession of the Karst District of Slovenia and Italy. They record environmental conditions, which are linked with both local and global events.

Cretaceous shallow-marine carbonate rocks of SW Slovenia were deposited in the northern part of the Adriatic Carbonate Platform. A 560-m-thick continuous Upper Cenomanian to Santonian carbonate succession has been studied near Hrusica Village in Matarsko Podolje. With regard to lithological, sedimentological, and stratigraphical characteristics, the succession has been divided into nine lithostratigraphic units, mainly reflecting regressive and transgressive intervals of larger scale. During the latest Cenomanian and Early Turonian, hemipelagic limestones were deposited on top of shallow-marine lagoon and peritidal Upper Cenomanian deposits indicating relative sea-level rise. Subsequently, the deeper marine depositional setting was gradually filled by clinoform bioclastic sand bodies overlain by peritidal and shallow-marine low-energy mainly lagoonal lithofacies. Similar lithofacies of predominately inner ramp/shelf depositional settings prevail over the upper part (i.e., Coniacian to Santonian) of the succession. In the area, the Upper Cetaceous carbonate rocks are separated from the overlying Lower Eocene (Upper Paleocene?) carbonate sequence by regional unconformity denoted by distinct paleokarstic features. On the Adriatic Carbonate Platform the deeper marine carbonate setting, developed at the Cenomanian/Turonian boundary, is usually correlated with OAE2 and related eustatic sea-level rise. Similarly, subsequent reestablished shallow-marine conditions are related to Late Turonian long- and short-term sea-level fall. However, we are suggesting that deeper marine deposits were deposited in a tectonically induced intraplatform basin formed simultaneously with the uplift of the northern and northeastern marginal parts of the Adriatic Carbonate Platform.

Carbonate and total organic carbon stable isotope analyses of the Upper Permian and Lower Triassic succession in the Masore section in western Slovenia indicate a high storage of organic matter during the Upper Permian, as well as the well known worldwide “light carbon isotope event” across the P/Tr boundary. The perturbations in the global carbon cycle observed in the investigated section span an approximately 50 cm thick interval (from −11 cm below to +41 cm above the lithostratigraphically determined P/Tr boundary), and coincide more or less with changes in lithology, as well as with an abrupt disappearance of Upper Permian marine fauna. In this section changes in the sedimentary environment are most probably related to Upper Permian—Lower Triassic sea level changes. The carbonate and organic carbon negative peak anomaly could be explained by accelerated changes in the end Permian carbon cycle, due to some co-occurring events, such as pronounced erosion and oxidation of organic carbon, a possible release of methane from stored hydrates, and volcanic activity, as well as by a sudden reduction in primary productivity triggered by not yet completely satisfactorily explained mechanisms.

Jelaska Vladimir, Gusic Ivan, Jurkovšek Bogdan, Ogorelec Bojan, Cosovic V., Sribar L., Toman M. The Upper Cretaceous geodynamic evolution of the Adriatic-Dinaric carbonate platform(s). In: Géologie Méditerranéenne. Tome 21, numéro 3-4, 1994. Perimediterranean carbonate platforms. First International Meeting. Marseille – France (5-8 septembre 1994) sous la direction de Jean-Pierre Masse. pp. 89-91.

The Vreme beds are part of the Liburnian Formation. At Dolenja vas which is situated on the Trieste-Komen platform, the Upper Maastrichtian age has been proved with co-occurring rudistids and foraminifera.

Valanginian to Lower Hauterivian carbonates from the Dinaric carbonate platform are analyzed in regard to the interrelation of biogenic constituents, cement types and sedimentary fabrics. Biogenics are predominantly benthic foraminifera, green algae (Bankia striata, Cayeuxia sp.), ostracods, gastropods, and stromatolitic algal-laminations. Cements observed in the limestones are calcitic throughout. Nevertheless, from the relic textures observed, their primary mineralogy can be deduced. Evidence is given that they originally consisted of either aragonite, Mg-calcite or calcite. Cements are marine phreatic and vadose and meteoric vadose cements (isopachous rims with bladed and needle relict textures and isopachous radiaxial fibrous rims; gravitational cements with bladed, needle and algal relict textures and gravitational radiaxial fibrous cements; granular gravitational cements). Fine- to coarse-granular and poikilotopic cements occur commonly but cannot be used for this analysis. Sedimentary fabrics are birds-eyes, solution molds, algal laminations, geopetal micrite and vadose crystal silt.

A profile of about 1400 m thickness near the village of Trnovo in the Trnovo forest in SW-Slovenia was studied for the microfacies and diagenetic development of the carbonate rocks. Because of the detailed biostratigraphic subdivision being just in improvement, the interval from the problematic Jurassic/Cretaceous to the Tertiary boundary (Berriasian-Cenomanian, fault, Senonian) was subdivided into ten zones and several subzones. These subdivisions are of practical use and can be found in profiles studied in other areas of SW-Slovenia and Istria as well. The data are based on field observations, thin sections and acetate peels. The following development can be recognized: (1) During the Berriasian(?)-Hauterivian a shallow-marine to intertidal restricted environment was established on the coherent Dinaric Carbonate Platform. This is indicated by low faunal diversity and numbers as well as the common occurrence of marine and meteoric vadose cements, birdseyes and algal-layers.Clypeina jurassica, Bankia striata, Favreina salevensis, and trocholinid foraminifera are chacteristic of the lowermost part (Uppermost Jurassic?, Berriasian-Valanginian) of this section. (2) In the Barremian-Aptian a lagoonal environment with patch reefs was established, characterized by normal marine conditions. High faunal and floral diversity and large numbers occur (hydrozoans, corals,Palorbitolina lenticularis, Salpingoporella dinarica). During this time period the platform was divided into smaller tectonic units with different facies development. (3) An open marine ingression from the Slovenian Basin occurred in the Albian, indicated by dolomitic limestones rich in sponge spicules and silica nodules and layers. (4) In the Cenomanian, mainly bioclastic sands (rich inOrbitolina conica) and micritic limestones (withPithonella) were deposited in alternation with micrites rich in ostracods and limestones containing birdseyes, vugs, and microsparite. This indicates a strong interfingering of different facies on a gently dipping ramp, probably due to sea level fluctuations. (5) The Turonian is missing in the section analyzed due to a fault. (6) In the Senonian bioclastic sands rich in fragments ofSabinia sp. were deposited around rudist mud mounds formed in inner shelf areas under normal marine conditions. Eocene flysch overlies the sequence and influences it diagenetically by silica authigenesis in the upper decimeters of the underlying limestones.

An Upper Jurassic Oxfordian and lower Kimmeridgian reef complex is well exposed in the area of Slovenia northwestern Yugoslavia This reef complex is thought to be a barrier reef that developed along the shelf margin of an ancient carbonate platform From basin to lagoon the following subdivisions have been delineated a fore reef area characterized by carbonate breccias and blocks of reef debris a central reef area with abundant hydro zoans and corals that can be further subdivided into actinostromariid and parastromatoporid zones and a back reef area with locally developed lagoons and patch reefs defined as the Cladocoropsis zone EXTENT OF REEF COMFLEX In the province of Slovenia coral hydrozoan reefs of Middle Devonian Upper Carboniferous Upper Triassic Upper Jurassic Lower and Up per Cretaceous and Oligocene ages are well ex posed Of these the Upper Jurassic barrier reef complex has the largest geographical extent This barrier reef complex can be traced in a more or less continuous series of outcrops from the Soca Valley across the central portion of Slovenia to Metlika into neighboring Croatia and then along the entire Yugoslav Dinaric region into Albania The reef complex also extends westward from the Seca Valley into Italy In Slovenia the reef com plex extends for approximately 140 kilometers in length is about 20 kilometers in width and ranges in thickness from 200 to 600 meters Fig I Pos tulated restored length of the reef trend possibly amounted to at least several hundred kilometers a distance comparable to that of the present Aus