PURBECKIAN LIMNIC OSTRACODA REWORKED IN THE EARLY MIOCENE MARINE DEPOSITS OF THE VIENNA BASIN, SLOVAKIA

Burdigalian clays with thin silty tempestites layers outcropped near the village Cerová have been investigated for its abundant neritic/bathyal vertebrate and invertebrate fauna.Among the Miocene marine neritic ostracoda, we have found well-preserved limnic Mesozoic ostracodsCetacella armata Martin, 1958, Cypridea ex gr. tumescens (Anderson, 1939), Cypridea cf. altissima Martin 1940, Mantelliana perlata Wienholz, 1968, Theriosynoecum forbesii (Jones, 1885), Darwinula sp. These taxa were a part of the limnic Mesozoic ostracod fauna wide-spread over the world, which disappeared in the Europe with marine Aptian transgression and was replaced in the Late Cretaceous by new and modern ostracod taxa (Babinot et al., 1996).A presence of Theriosynoecum forbesii (Fig. 1A) confirms that these limnic ostracods were reworked to the Early Miocene deposits from the Late Jurassic/Early Cretaceous deposits of the Theriosynoecum forbesii Zone, equal to the Tithonian/Berriasian age. In the lithostratigraphical division, this zone corresponds to Purbeck and lower Hastings Groups known from the southern England and north-western France (Horne 1995).With a respect to this biostratigraphical attribution, this discovery induces a paleogeographical problem on a source geological unit because no limnic Late Jurassic/Early Cretaceous deposits have been found in the Central Europe till now. The eastern edge of the Bohemian Massif can be regarded as the most possible source, which was at this time emerged land (Fig. 1B). Unfortunately preserved Late Jurassic/Early Cretaceous deposits are of marine origin and a lack of the Purbeckian limnic deposits is underlined by Lower Cretaceous regression and karstification of the older deposits. Moreover, well-preserved ostracod valves without any marks of transport-related holes and smoothening of the ornamentation, and a relatively large distance of the deposition area from the Bohemian Massif make this “source” questionable, even impossible. Perfect preservation requires a transport on a short distance from the neighboring geological units. Central Western Carpathian geotectonic units can be hardly accepted as a possible source, due their continual and fully marine Late Jurassic–Early Cretaceous sedimentary sequence. The only source of the Purbeckian deposits, which could be partially emerged in that time, can be situated in the Outer Western Carpathians, however this limnic depositswere completely eroded

Lower Miocene plant assemblage with coastal-marsh herbaceous monocots from the Vienna Basin (Slovakia)

A new plant assemblage of Cerová-Lieskové from Lower Miocene (Karpatian) deposits in the Vienna Basin (western Slovakia) is preserved in a relatively deep, upper-slope marine environment. Depositional conditions with high sedimentation rates allowed exceptional preservation of plant remains. The plant assemblage consists of (1) conifers represented by foliage of Pinus hepios and Tetraclinis salicornioides, a seed cone of Pinus cf. ornata, and by pollen of the Cupressaceae, Pinaceae, Pinus sp. and Cathaya sp., and (2) angiosperms represented by Cinnamomum polymorphum, Platanus neptuni, Potamogeton sp. and lauroid foliage, by pollen of Liquidambar sp., Engelhardia sp. and Craigia sp., and in particular by infructescences (so far interpreted as belonging to cereal ears). We validate genus and species assignments of the infructescences: they belong to Palaeotriticum Sitár, including P. mockii Sitár and P. carpaticum Sitár, and probably represent herbaceous monocots that inhabited coastal marshes, similar to the living grass Spartina. Similar infructescences occur in the Lower and Middle Miocene deposits of the Carpathian Foredeep (Slup in Moravia), Tunjice Hills (Žale in Slovenia), and probably also in the Swiss Molasse (Lausanne). This plant assemblage demonstrates that the paleovegetation was represented by evergreen woodland with pines and grasses in undergrowth, similar to vegetation inhabiting coastal brackish marshes today. It also indicates subtropical climatic conditions in the Vienna Basin (central Paratethys), similar to those implied by other coeval plant assemblages from Central Europ

Revisiting the Age of Jurassic Coral Bioherms in the Pieniny Klippen Belt (Western Carpathians) on the Basis of Benthic Foraminifers

Coral bioherms of the Vršatec Limestone that formed massive, several tens of meters thick complexes during the Jurassic were important sources of carbonate production, with carbonate sediment exported to deeper parts of the Pieniny Klippen Basin (Western Carpathians). However, the age of these carbonate factories remains controversial. New analyses of benthic foraminiferal assemblages occurring in coral bioherms and peri-biohermal deposits of the Vršatec Limestone at five sites in the western Pieniny Klippen Belt (Vršatec-Castle, Vršatec-Javorníky, Malé Hradište, Malé Hradište-Kalvária, and Drieňová Hora) show that these sediments were deposited during the Bajocian and were lateral equivalents of crinoidal limestones and breccias, in contrast to previous studies suggesting that they were deposited during the Oxfordian. First, all sites are characterized by similar composition of foraminiferal assemblages on the basis of presence–absence data, although foraminiferal assemblages in biosparitic facies at Vršatec are dominated by miliolids whereas biomicritic facies at Malé Hradište are dominated by the spirillinid Paalzowella. The composition of foraminiferal assemblages does not differ between the lower and upper parts of the Vršatec Limestone. Second, foraminifer species that were assumed to appear for the first time in the Oxfordian already occur in the Middle Jurassic sediments of the northern Tethyan shelf. Third, the first and last appearances of foraminifers documented in other Tethyan regions are in accordance with stratigraphic analyses and ammonoid occurrences, demonstrating that bioherm-forming coral communities developed on the Czorzstyn Ridge during the Bajocian. Several species of foraminifers of the Vršatec Limestone appeared for the first time during the middle or late Aalenian (Labalina occulta, Paalzowella feifeli) and during the Bajocian (Hungarillina lokutiense, Radiospirillina umbonata, Ophthalmidium caucasicum, O. terquemi, O. obscurum, Paalzowella turbinella, Cornuspira tubicomprimata, Nubecularia reicheli) or appeared for the last time in the Bajocian (Tethysiella pilleri) or Early Bathonian (Ophthalmidium caucasicum, O. obscurum). The composition and diversity of communities with benthic foraminifers of the Vršatec Limestone is similar to the composition of foraminiferal communities on carbonate platform environments with corals of the French Jura and Burgundy during the Bajocian

Miocene sepiids (Cephalopoda, Coleoidea) from Australia

Two sepiid genera, Notosepia Chapman, 1915, andSepia Linnaeus, 1758, are described from the Neogene deposits ofAustralia. A new and unique record of the middle Miocene Sepia sp.is reported from southern Australia. Based on similarities to contemporaneoussepiids, the new sepiid cuttlebonedescribed herein belongs to the genus Sepia. Notosepiacliftonensis is suggested herein to be a descendant of the archaeosepiidstem lineage. Microstructures (lamella-fibrillar nacre is the nacre Type II ofsepta and pillar prismatic layers) of the excellently preserved cuttlebone ofSepia sp. display a modern character of the phragmocone, fullycomparable to the recent taxa. The stratigraphically well-calibrated (basedon foraminifera) cuttlebone represents the first unambiguous fossil record ofthe genus Sepia from the Southern Hemisphere. It significantlyextends the biogeographical distribution of modern sepiids in the Miocene andsuggests the existence of a sepiid eastward migratory route. Moreover, thepresence of both conservative- and modern-type cuttlebones suggests a dualcolonisation of Australian waters: the first (archaeosepiid) during the lateEocene–late Oligocene and the second (sepiid) during the early Miocene

Venezuelan sandstone caves: a new view on their genesis, hydrogeology and speleothems

Caves in arenites of the Roraima Group in Venezuela have been explored on the Chimantá and Roraima plateaus (tepuis). Geological and geomorphological research showed that the most feasible method of caves genesis was the winnowing and erosion of unlithified or poorly lithified arenites. The unlithified arenitic beds were isolated by wellcemented overlying and underlying rocks. There is a sharp contrast between these well-lithified rocks and the loose sands which form the poorly lithified to unlithified beds. They are only penetrated by well lithifi ed pillars originated by vertical finger flow of the diagenetic fluids from the overlying beds. Such finger flow is only typical for loose sands and soils where there is a sharp difference in hydraulic conductivity. The pillars exhibit no signs of further dissolution. The caves form when the flowing water accesses the poorly lithified beds through clefts. Collapse of several superimposed winnowed-horizons can create huge subterranean spaces. Futher upward propagation of the collapses can lead to large collapse zones which are commonly observed on the tepuis. Dissolution is also present but it probably plays neither a trigger role, nor a volumetrically important role in the cave-forming processes. The strongest dissolution/reprecipitation agent is condensed air moisture which is most likely the main agent contributing to growth of siliceous speleothems. As such, it can be active only after, but not before the cave is created. Siliceous speleothems are mostly microbialites except for some normal stalactites, cobweb stalactites and flowstones which are formed inorganically. They consist of two main types: 1. fine-laminated columnar stromatolite formed by silicified filamentous microbes (either heterotrophic filamentous bacteria or cyanobacteria) and 2. a porous peloidal stromatolite formed by Nostoc-type cyanobacteria. The initial stages of encrusted shrubs and mats of microbes were observed, too, but the surrounding arenitic substrate was intact. This is strong evidence for the microbial mediation of silica precipitation

Venezuelan tepuis: their caves and biota

From the Preface: The world at the top of the tepuis of Venezuela is amazing. Ever since Sir Arthur Conan Doyle wrote The Lost World , the enigma of the South American steep and isolated table-mountains have attracted many people. Everyone in our research team dreamt about exploring these blank spaces on the map . However, despite this great attraction, scientific literature concerning tepuis has remained rather scarce. We are therefore proud to present this scientific monograph on tepuis, which is considered to be only the second issue of its kind, following the work of Huber (1992). This volume summarizes the main scientific results of expeditions to these tepuis between 2002 and 2011. The major research described in this monograph is dedicated to the great caves discovered in Roraima and Churí tepuis. The geological research was accompanied by biological research on cave and surface fauna, with a special focus on malacofauna, herpetofauna and insects. Although some of the data from this research has been previously published in scientific articles, it did not always obtain the justifiable space to present all gathered documentation and to elucidate all relevant scientific problems from a greater perspective. It is therefore our great pleasure to present this monograph containing detailed information on all research currently performed by our interdisciplinary research team. This is accompanied by a large number of fascinating photographs and several informative maps and diagrams. The greatest benefits to be gained from this combined monograph compared to short scientific publications is that more space is available to discuss currently unresolved problems, to ponder new intriguing questions and to envisage future necessary research. It is our sincere hope that all our readers will appreciate the unique information presented in this manner, and we hope you will really enjoy this monograph and find interesting topics for your research. Open Access See Extended description for more information