The Paleogene “megabeds” of the Julian-Slovenian Basin are regional, basin-wide deposits, produced by catastrophic carbonate platform collapses. They record the emplacement of a bipartite slide mass ...behaving as a cohesive blocky/debris flow in the lower part, and as a grain to turbulent flow in the upper part. Several types of primary (sedimentary) soft sediment deformation structures testify fluid overpressure conditions during emplacement. Such structures are identified within a brecciated, fine grained matrix that encloses and intrudes slide blocks and clasts, characterized by NE-, NW- and SW-directed paleo-transport directions, indicating a depositional setting close to the basin margins. Here we present an updated review of some representative megabeds, exposed in the open-pit quarry outcrops of Anhovo (SW Slovenia). In particular, we here discuss new interpretations based on X-ray fluorescence spectrometry (XRF), thermo-gravimetry (TG) and electric resistivity tomography (ERT). Our results indicate that basal marly clasts of the megabeds are markedly different from the uppermost draping marls, suggesting two different coeval sources. The relationships with the underlying successions are strongly erosive, with deep localized scouring of the substrate and amalgamations between different megabeds, and the depositional units inside individual megabeds, supporting the geochemical differences.
From the Maaslrichtian up to the Early Eocene, the Julian (or Slovenian) Basin is characterized by a mixed siliciclastic/carbonale deposits system which exhibit complex sedimentalion patterns ...depending on various controls: sea level changes; tectonic movements in both carbonate platform and northern source areas; subsidence; proximity/distality to siliciclastic, calciclastic, allodapic (carbonate) sediment source areas; abundance of terrigenous detritus; paleomorphology of the slope of the Friuli Platform, the main source of carbonate detritus. The depositional sequences ofthe Julian Basin are the result of these controls and their interaction. Herein the examination of the stratigraphic sections is restrictedto the Middle Paleocene up to the Early Eocene ("Flysch di Masarolis"and "Flysch del Grivo"),where the most important carbonate megabedsare recognized. Fourteen stratigraphic sections of the "turbidites with megabeds" sequence were examined (mainly along the N-S direction).All sections are located near the southern margin of the basin,at the foot of the slope of the north-eastern edge of the Friuli Platform.Comparison of log s revealed marked differenoes in the thickness of the megabeds and of the interbedded calciturbidites and siliciclaslic turbidites. This could be ascribed to the proximity to the source areasof mega beds and to the abrupt stope morphology.By means of the litho-biostratigraphic analysis of the sedimeents which filled the Julian Basin, the provenances from the main sourceareas are outlined. The prevailing calciclastic detrilus (CE ,I) mixedwith allodapic carbonate sediments (CI) came from the South; siliciclastic detritus (N CE) mixed with other calciclastic detritus (CE,II) from N, NW as consistently indicated by paleocurrent directions;minor (and late) mixed carbonate sediments (CE, ill) came from NE.A rough sedimentary balance comprising megabeds, thick beds, multisource turbidites (siliciclastic, carbonate, mixed plus couplets)is calculated.An attempt to apply the eustatic sea level curve of Haq et al. (1987)to Maastrichtian-Paleocene and Eocene deposits of the Julian Basinis made. Lowstands of the Maastrichtian- Paleocene and of the Late Ypresian are well recognizable. More problem s arise upon examining the "Flysch del Grivo" section which is strongly controlled by tectonic mechanisms. The triggering mechanisms for mega bed emplacement in the Julian Basin is related to seismic activity along the southern border of the basin. In conclusion, the "turbidites with megabeds" sequence is integrated within the framework of the geological evolution of the Julian Basin.
The Early Middle Cenomanian margin sequence of Val ludrio, connected with the northeastem margin of the Friuli Platform shows intercalated layers with pelagic organisms: Calcisphaerulidae and ...planktonic forams, among which is Favwsella. These are interpreted as transgressive episodes recorded in a calbonate ramp sequence related to a tectonically subsiding margin. ln the Dinaric and Friuli Platforms two distinct Calcisphaerulidae and planktonic forams facies are distinguished for the Cenomanian. The first one, of early-middle Cenomanian age, which is also present in the ludrio sequence, developed in platform margin zones subjected to drawning. The second one, of late Cenomanian age, developed in more internal areas of the Dinaric and Friuli Platforms, and can be related to the transgression associated with the OAE 2 event.
The genera Balabania Karacabey-Öztemür, Branislavia Sladić-Trifunović and Klinghardtites Lupu have previously been referred to as three new canaliculate radiolitid taxa. Well-preserved articulated ...shells of these rudist genera collected from eastern Turkey, Serbia and western Romania have now been re-examined and compared with the rudist literature. They have pallial canals in the originally aragonitic inner shell layer of the left valve flanking the cardinal apparatus and a long ligamental ridge, which are the diagnostic characteristics of Colveraia Klinghardt. As a result, two species are recognised here, namely Colveraia acuticostata (Karacabey-Öztemür), encompassing all species of Balabania and Colveraia bacevicensis (Milovanović) for all species referred to Branislavia. Klinghardtites musculosus (Klinghardt) is herein regarded to be synonymous with Colveraia darendeensis Karacabey. The left valve of Colveraia acuticostata is cap like with an eccentric apex inclined gently or strongly towards the dorsal side and overlap with the commissure and has flat or rarely slightly concave radial bands. Colveraia bacevicensis is characterised by deeply concave radial bands, and longitudinal ribs and grooves of the right valve, both of which are crossed by strongly folded growth lines that overlap each other and present distinct undulations on the surface of the valve. Ornamentation of the valve and the structure of the radial bands distinguish them from Colveraia variabilis Klinghardt and C. darendeensis Karacabey. Our re-examination of specimens previously described as Balabania acuticostata Karacabey-Öztemür from eastern Serbia shows that these can be included in C. darendeensis. A biogeographical overview of species of Colveraia in the Mediterranean Tethys is presented.
•The rudist bivalve genera Balabania Karacabey-Öztemür, 1980, Branislavia Sladić-Trifunović, 1981 and Klinghardtites Lupu, 1971 have been revised and their synonymy with Colveraia Klinghardt, 1921 proposed due to the presence of the pallial canals in the aragonitic inner shell layer of the left valve and a long ligamental ridge.•Two Colveraia species are recognized: C. acuticostata (Karacabey-Öztemür, 1980) for all Balabania specimens and C. bacevicensis (Milovanović) for all Branislavia specimens.•Klinghardtites Lupu, 1971 herein regarded as synonymous with Colveraia darendeensis Karacabey, 1974.•The re-examination of the specimens previously described as Balabania acuticostata Karacabey-Öztemür, 1980 from the Eastern Serbia are also included to C. darendeensis.•We review the palaeogeographical distribution of the species of Colveraia in the Mediterranean Tethys.
The rudist genus Joufia Boehm is characterized by radially oriented canals within the calcitic outer shell layer of the left valve. The type species, J. reticulata, has multiple rings of canals. ...However, a single ring of such canals is observed in the left valves of some other nominal radiolitid genera. One such is Kuehnia serbica Milovanović, recognized herein as a species of Joufia, to which we also re-assign Parasauvagesia cappadociensis Cox.
Pseudokuehnia Slišković and other material historically attributed to Kuehnia share with J. serbica: (i) the single ring of radial canals in the left valve; (ii) similar right valve ornamentation; (iii) identical celluloprismatic mesostructure and pseudopillar-like structures in the right valve; plus pallial canals in the left valve, as seen in Joufia reticulata. Additionally, the left valve of Pseudokuehnia has a postero-ventral pair of tubular structures; and the same characters are also seen in Kurtinia Karacabey-Öztemür, herein regarded as synonymous with the latter taxon.
Hence, we recognize three Joufia species: (1) J. reticulata Boehm, with multiple canal rings in the left valve; (2) J. serbica (Milovanović), with a single ring of such canals; and (3) J. milovanovici Slišković, also with a single ring of canals, but additionally with paired tubular structures in the left valve. The same tripartite division exists among specimens from latest Campanian-Maastrichtian deposits in Turkey.
Thus revised, Joufia ranged across the Mediterranean Tethys from Turkey via the Balkans to Italy and SE Spain, and as far south as central Tunisia and SE Turkey.
The paper aims to present the geology of the western part of the Classical Karst (NW Dinarides), located at the border between Slovenia and Italy. The work is based on archive, published and new data ...collected by Slovenian and Italian researchers within several scientific national and Cross Border Cooperation projects. The map, produced at a scale of 1:50,000, summarizes the lithological and structural setting and is supplemented by three geological cross-sections of the study area.
An examination of the historical material of Colveraia variabilis Klinghardt, 1921 housed in the collections of the Steinmann Institute of Palaeontology (Bonn, Germany) and of some newly collected ...specimens from the type area of Mt. Jouf (Friuli, NE Italy) has revealed many previously unknown characters of this radiolitid. Klinghardt had only large fragments of Colveraia variabilis at his disposal and he erred in some respects, mainly by mistaking the upper valve for the lower one. Representatives of the genus Colveraia have been collected at different localities of the Central-Eastern Mediterranean Tethys and the Arabian Plate, but the majority of these have never been described in detail or have been identified solely on the basis of transverse sections, except in Turkey, where many well-preserved specimens have been recovered. Historical and new examples of Colveraia variabilis from Mt. Jouf and the material recovered from Turkish localities show different external characters as far as radial zone, general shell shape and ornamentation are concerned. These lead us to assign all Turkish specimens to Colveraia darendeensis Karacabey, 1974, which is here described in detail. Comparisons with congeneric forms from the Central-Eastern Mediterranean Tethys and the Arabian Plate are also made.
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.
İyi tanınan paleontoloji lokalitesi Bačevica (Doğu Sırbistan)'ya oldukça yakın bir alanda yüzeyleyen litolojik ve
faunal istif süreksiz ve kötü korunmuş bir kesitte tanımlanmıştır. Kesitin ...klastik tortullarca baskın olduğu yerlerde
'Vrbovac reef ' olarak tanımlanan fasiyes gözlenememiştir. Kesitin taban bölümü, kireçtaşı breşlerinden oluşan alt birim
ve fosilce zengin üst kısımdan yapılıdır. Üst kısımda aynı zamanda, seyrek silt ve kumca baskın kireçtaşı breşleri ve
siltli/kumlu topraklar gözlenir. Faunal istif, monospesifik-posispesifik topluluklarının ardalanmasını ve oldukça çeşitli
rudist topluluklarını içerir. Bačevica'da tanımlanan farklı rudist örneklerinin stratigrafik dağılımı, Orta Tetis
bölgesi'ndeki geç Kampaniyen tortullarının biyostratigrafik korelasyonu için önemli bir veri teşkil etmektedir. Özellikle
Pseudopolyconites içeren düzeyler, birkaç fosilli lithosoma dahil edilebilir gibi görünmektedir. Pseudopolyconites'in
yirmi türü ligament çıkıntısının özelliklerine dayanılarak Sırbistan rudist uzmanlarınca tanımlanmıştır. Literatürde
örneklendirilmiş olan Pseudopolyconites'in sağ kavkısının enine kesitlerinde biyometrik analizler yapılmıştır. Ligament
çıkıntısındaki genişlik değişiminin tek başına birçok türün tanımlanması için sağlıklı bir veri olmadığı ve olasılıkla basit
bir eko-morfotip olabileceği anlaşılmıştır.
The lithological and faunal succession cropping out close to the famous palaeontological locality of Bačevica
(Eastern Serbia) is described along a very discontinuous and ill-exposed section. Since the section is dominated by
clastic sediments, no-vestige of the so-called 'Vrbovac reef ' has been observed. Rhythms consisting of a limestone
breccia lower unit and a fossil-rich upper part characterize the base of the section while rare silt and sand-rich limestone
breccias and prevailing silty/sandy soils are the lithologies observed in the upper part of the same. The faunal succession
shows an alternation of monospecific-paucispecific assemblages and much more diverse assemblages of rudists. The
stratigraphic distribution of the different examples of rudist bivalves recovered at Bačevica may represent a significant
tool for biostratigraphic correlations as far as the late Campanian deposits in the Central Tethys area are concerned. In
particular, the Pseudopolyconites-bearing strata seem to be included within a few fossiliferous lithosomes. Therein the
Serbian rudistologists instituted twenty species of Pseudopolyconites on the base of the characteristics of their ligamental
ridge. Biometrical analyses have been made on the transverse sections of the right valves of the Pseudopolyconites
holotypes illustrated in the scientific literature. It is suggested that the wide variability of the ligamental ridge shape
alone does not warrant the institution of so many species of the genus in question but the existing ones should probably
be re-considered as simple eco-morphotypes.
PDF
