Late Carboniferous floras of Slovenia - a review

This paper provides a short review of the Late Carboniferous floras in Slovenia. The Namurian-Westphalian or Westphalian A (Langsettian) flora was collected in the Sava Folds, whereas the late Westphalian and/or Stephanian flora was documented in the Southern Karavanke Mts. The recovered assemblages are well represented by horsetails, arborescent lycopsids, fern-like foliage (ferns and pteridosperms) as well as gymnosperms, and they correspond to the general features of the Euramerican flora.</p

NEW TRIASSIC ASTEROIDEA (ECHINODERMATA) SPECIMENS AND THEIR EVOLUTIONARY SIGNIFICANCE

The Paleozoic-Mesozoic transition saw the disappearance of asteroid stem groups and the ascent of the crown group, but late Paleozoic and Triassic asteroids are rare and transition events are poorly documented. Three new Middle and Late Triassic specimens augment existing data; included are a specimen of Trichasteropsis weissmanni from Germany, a specimen of Trichasteropsis? sp. indet. from Italy, and a possible member of the extant Poraniidae from Slovenia. Presence of a small ossicle at the interbrachial midline and adjacent to the marginal series of the new T. weissmanni specimen is consistent with similar expressions not only of other trichasteropsids but also occurrence of two interbrachial ossicles in Paleozoic, stem-group asterozoans; presence is in turn consistent with a hypothesis of derivation of the axillary/odontophore coupling from two ossicles rather than direct derivation of the crown-group odontophore from a single stem-group axillary. Morphology of Trichasteropsis? sp. indet., including, for example, the evenly-tapering arms are reminiscent of those of diverse crown-group asteroids whereas the enlarged distal arms of T. weissmanni are unique, the morphology of T? sp. indet. thereby potentially indicative of a plesiomorphic, stemward positioning within the Trichasteropsiidae. The range of the Poraniidae is tentatively extended to the Carnian. Similarities shared by the Poraniidae and the Trichasteropsiidae suggest stemward positioning within crown-group diversification; however, known Triassic fossils do not appear closely related to extant taxa identified in recent molecular studies as basal within the crown-group. A temperate climate is suggested as preferred by the Triassic asteroids rather than a tropical, warmer one

Microfossils from Middle Triassic beds near Mišji Dol, central Slovenia

Middle Triassic beds exposed along the road between Mišji Dol and Poljane pri Primskovem (Posavje Hills) comprise marlstone, tuff, volcaniclastic sandstone, and thin- to medium-bedded limestone and dolostone. The succession was logged and sampled for conodonts. A relatively rich conodont assemblage was determined, consisting of Budurovignathus gabrielae Kozur, Budurovignathus sp., Cratognathodus kochi (Huckriede), Gladigondolella malayensis Nogami, Gladigondolella tethydis Huckriede, Gladigondolella sp., Neogondolella balkanica Budurov & Stefanov, Neogondolella cf. excentrica Budurov & Stefanov, Neogondolella constricta (Mosher & Clark), Neogondolella cornuta Budurov & Stefanov, Neogondolella sp., Paragondolella excelsa Mosher, Paragondolella liebermani (Kovacs & Kozur), Paragondolella trammeri (Kozur), Paragondolella cf. alpina (Kozur & Mostler), and Paragondolella sp. The assemblage correlates with the upper Anisian and lowermost Ladinian assemblages from the Global Boundary Stratotype Section and Point (GSSP) of the Ladinian at Bagolino in the Southern Alps in northern Italy. Along with conodonts, numerous specimens of benthic foraminifera Nodobacularia? vujisici Urošević & Gaździcki were recovered from the lowermost part of the succession. Previous research on this taxon is critically evaluated

SREDNJOTRIJASKE AUTOKLASTIČNE NASLAGE U OKOLICI BOSANSKOG GRAHOVA (JUGOZAPADNA BOSNA I HERCEGOVINA)

Middle Triassic volcanic and volcaniclastic rocks have been recognized at several localities near Bosansko Grahovo, in southwestern part of Bosnia and Herzegovina in the External Dinarides. Peculiar types of autoclastic rocks were investigated. These are peperites and hyaloclastites. Regarding specific structures, mineral composition and micropetrographic characteristics it was possible to further differentiate hyaloclastites into in situ hyaloclastites and slightly resedimented hyaloclastites that represent genetic succession. All rock types occurred in a deep sea troughs that formed as a consequence of Middle Triassic extensional tectonic and rift related wrench faulting. In situ hyaloclastites and slightly resedimented hyaloclastites were formed due to quenching at the contact of lava effusions with sea water. Genesis of peperites is related to lava emplacement in unconsolidated water saturated lime mudstones that were deposited in deep sea basin. All investigated rock types represent first findings of autoclastic deposits in the External Dinarides. Biostratigraphic constraints achieved by means of conodont species Neogondolella excentrica, Paragondolella excelsa, Paragondolella trammeri and Gladigondolella tethydis indicate Late Anisian to Early Ladinian interval of the autoclastic deposits from Bosansko Grahovo.U okolici Bosanskoga Grahova u jugozapadnome dijelu Bosne i Hercegovine (vanjski Dinaridi) istražen je specifičan tip vulkanoklastičnih stijena – autoklastične stijene srednjotrijaske starosti. Izdvojena su dva osnovna tipa autoklastičnih naslaga: peperiti i hijaloklastiti. Geneza peperita povezana je s procesima smještanja lave u nekonsolidirane, vodom zasićene vapnenačke madstone koji imaju karakteristike taloženja u pelagičkome okolišu. S obzirom na specifičnu teksturu, mineralni sastav i mikropetrografske karakteristike hijaloklastiti predstavljaju genetski slijed na opisanome lokalitetu Bosansko Grahovo I, te su podijeljeni na a) in situ hijaloklastite, b) neznatno pretaložene hijaloklastite i c) pretaložene hijaloklastite. In situ hijaloklastiti i neznatno pretaloženi hijaloklastiti nastali su fragmentacijom užarene lave bazaltnoga sastava u doticaju s hladnom morskom vodom, dok pretaloženi hijaloklastiti predstavljaju dominantno vulkanski detritus s kojim je pomiješana mala količina klasta vapnenaca i/ili rožnjaka, te se smatra da je detritus pretaložen nakon fragmentacije, vjerojatno, u blizini primarnih magmatskih izljeva bazaltne lave. Svi tipovi stijena označavaju magmatsku aktivnost u dubokomorskim jarcima formiranim kao posljedica srednjotrijaske ekstenzije i normalnoga rasjedanja asociranoga s procesima nastajanja rifta. Opisane autoklastične stijene prvi su pronalazak autoklastičnih naslaga u vanjskim Dinaridima. Biostratigrafska odredba temeljena na nalazima konodontnih vrsta iz vapnenaca peperita (Neogondolella excentrica, Paragondolella excelsa, Paragondolella trammeri i Gladigondolella tethydis) upućuje na kasnoanizičku do ranoladiničku starost autoklastičnih naslaga Bosanskoga Grahova, a time i na početak vulkanske aktivnosti već u aniziku

Geology of the Classical Karst Region (SW Slovenia–NE Italy)

ABSTRACTThe 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

A glimpse of the lost Upper Triassic to Middle Jurassic architecture of the Dinaric Carbonate Platform margin and slope

In the southernmost outcrops of the Slovenian Basin the Middle Jurassic coarse-grained limestone breccia (mega)beds are interstratified within a succession that is otherwise dominated by hemipelagites and distal turbidites. In this paper, these beds are described as the Ponikve Breccia Member of the Tolmin Formation. We provide descriptions of the studied sections with detailed geological maps and analysis of the breccia lithoclasts. From the latter, a non-outcropping margin of the Dinaric Carbonate Platform is reconstructed. In the Late Triassic the platform margin was characterized by a Dachstein-type marginal reef. After the end-Triassic extinction event, the platform architecture remained, but the reefs were replaced by sand shoals characterized by ooids. In the late Early Jurassic and/or early Middle Jurassic a slope area might have been dissected by normal faults and a step-like paleotopography was formed. In the Bajocian, during a period of major regional geodynamic perturbations, extensional or transtensional tectonic activity intensified and triggered the large-scale collapses of the Dinaric Carbonate Platform margin producing the limestone breccias described herein. This may in turn have caused a backstepping of the platform margin, as is evident from the occurrence of Late Jurassic marginal reefs that are installed directly above the Upper Triassic and Lower Jurassic inner platform successions

FIRST REPORT ON THE UPPERMOST PERMIAN OSTRACODS FROM THE MASORE SECTION (EXTERNAL DINARIDES), SLOVENIA

The ostracod assemblages from the Upper Permian and Permian-Triassic transitional strata of the Masore section in the External Dinarides (Slovenia) were studied. Altogether 13 genera and 20 species of the orders Palaeocopida, Platycopida and Podocopida are identified and illustrated. All recovered ostracods belong to shallow marine taxa. The older fauna from the uppermost Permian and the younger fauna from the Permian-Triassic boundary strata are distinguished. The obtained fauna from the Permian Bellerophon Formation corresponds to the “benthonic ostracod Eifelian Mega-assemblage” occupying the shelf sea floors. This study presents the first report of ostracod faunas from the uppermost Permian and Permian-Triassic boundary interval of Slovenia. The recovered ostracod fauna display a distinct faunal change and yield important paleobiogeographic implications as it reveals similarity with stratigraphical equivalent faunas from some other neighboring localities in the western Paleotethys, such as Bulla in Italy, Komirić in Serbia, and the Bükk Mountains in Hungary

Late Carboniferous flora of Castle Hill in Ljubljana (Slovenia)

Finds of Paleozoic fossil flora on the Ljubljana Castle Hill were first described in 19th century, therefore the wider area of the planned cable car to the Ljubljana castle was defined as apotentially important fossil locality already before the start of construction works. During geologic-paleontologic monitioring a fossil assemblage of Equisetopsida (Articulatae), Lycopodiopsida (Lycopsida), Pteridospermopsida and Cordaitanthales that permit to confirm the Upper Carboniferous age of beds.The Castle Hill is the western mostlocality of Paleozoic flora in the Sava Folds,and itrepresents anadditional contribution to the knowledge on extension of the Euramerian floristic area