First find of the skeletal ossicles of eleutherozoid echinoderms from the Líšeň Formation (Famennian–Tournaisian) of the Moravian Karst

During a biostrati biostratigraphic survey of the Devonian-Carboniferous boundary in the Moravian Karst (Moravo-Silesian Zone, Czech Republic) an abundant microfauna was obtained. Besides the conodonts, diverse ichthyoliths, eleutherozoid and pelmatozoid echinoderms, bryozoans, inarticulate brachiopods and rare foraminifers were found in insoluble residues. This contribution is focused on the eleutherozoid echinoderms remains from interval of the late Famennian Middle Palmatolepis gracilis expansa conodont Zone to the early Tournaisian Siphonodella duplicata conodont Zone from the Lesní lom, Mokrá and Křtiny quarries (NE of Brno). The eleutherozoid echinoderms are generally less frequent than conodonts and ichthyoliths, however in two levels from the Lesní lom and Mokrá quarries (Famennian Protognathodus kockeli and Tournaisian Siphonodella bransoni Zones) are relatively common. The classes Ophiuroidea and Holothuroidea are reported for the first time from the Moravian Karst. Ophiuroids of the order Oegophiurida MATSUMOTO 1915 (genus Furcaster STÜRTZ, 1900), Phrynophiurida MATSUMOTO 1915 (genus ?Eospondylus GREGORY, 1897) and Stenurida SPENCER, 1951 were determinated. Presented are mainly arm vertebral ossicles. Holothurian sclerites belong to the order Dendrochirotida GRUBE, 1840 (genus Eocaudina MARTIN, 1952) and Apodida BRANDT, 1835 (Achistrum ETHERIDGE, 1881; ?Gagesiniotrochus BOCZAROWSKI, 2001). The most distinctive feature is the mass occurrence of the eleutherozoids elements just after the Hangenberg Event s. s. (last Famennian Protognathodus kockeli conodont Zone). The mentioned fauna probably represents a pioneer association and the presence of commonly opportunistic generalists as are ophiuroids and holuthuroids fits into this scenario.During a biostrati biostratigraphic survey of the Devonian-Carboniferous boundary in the Moravian Karst (Moravo-Silesian Zone, Czech Republic) an abundant microfauna was obtained. Besides the conodonts, diverse ichthyoliths, eleutherozoid and pelmatozoid echinoderms, bryozoans, inarticulate brachiopods and rare foraminifers were found in insoluble residues. This contribution is focused on the eleutherozoid echinoderms remains from interval of the late Famennian Middle Palmatolepis gracilis expansa conodont Zone to the early Tournaisian Siphonodella duplicata conodont Zone from the Lesní lom, Mokrá and Křtiny quarries (NE of Brno). The eleutherozoid echinoderms are generally less frequent than conodonts and ichthyoliths, however in two levels from the Lesní lom and Mokrá quarries (Famennian Protognathodus kockeli and Tournaisian Siphonodella bransoni Zones) are relatively common. The classes Ophiuroidea and Holothuroidea are reported for the first time from the Moravian Karst. Ophiuroids of the order Oegophiurida MATSUMOTO 1915 (genus Furcaster STÜRTZ, 1900), Phrynophiurida MATSUMOTO 1915 (genus ?Eospondylus GREGORY, 1897) and Stenurida SPENCER, 1951 were determinated. Presented are mainly arm vertebral ossicles. Holothurian sclerites belong to the order Dendrochirotida GRUBE, 1840 (genus Eocaudina MARTIN, 1952) and Apodida BRANDT, 1835 (Achistrum ETHERIDGE, 1881; ?Gagesiniotrochus BOCZAROWSKI, 2001). The most distinctive feature is the mass occurrence of the eleutherozoids elements just after the Hangenberg Event s. s. (last Famennian Protognathodus kockeli conodont Zone). The mentioned fauna probably represents a pioneer association and the presence of commonly opportunistic generalists as are ophiuroids and holuthuroids fits into this scenario

STRATIGRAFIE HRANIČNÍHO INTERVALU DEVON/KARBON V LESNÍM LOMU (BRNO-LÍŠEŇ)

Based on the high-resolution stratigraphic study (conodont biostratigraphy, carbonate sedimentology and petrophysics-gammaspectrometry) typical facial succesion of the global Devonian/Carboniferous boundary multiphase Hangenberg event was identified in the Lesní lom quarry (Brno-Líšeň, southern part of the Moravian Karst)

Preliminary report on the occurrence of the ichthyoliths in the Upper Famennian and Lower Tournaisian of the Moravian Karst

A relatively large number of microvertebrate remains (ichthyoliths) was obtained during a recent micropaleontological research of the Devonian-Carboniferous boundary interval from the Líšeň Formation, Moravian Karst. Sections were sampled from the late Famennian Middle Palmatolepis gracilis expansa to the early Tournaisian Siphonodella bransoni conodont Zones in bed-by-bed manner. Samples were dissolved in 15% acetic acid and ichthyoliths were hand-picked from the sieved insoluble residues and then studied under a binocular microscope. Preservation of many presented ichthyoliths is excellent, allowing determination on the genus or even species-level. Despite the well preservation, a large number of obtained ichthyoliths were preliminary assigned only to the higher taxonomic units. The ichthyoliths belong to a wide range of taxonomic groups comprising chondrichthyan, sarcopterygian, actinopterygian and acanthodian classes. The class Actinopterygii, chondrichthyan orders Squatinactiformes (Squatinactis sp.) and Ctenacanthiformes, symmoriid shark family Falcatidae (genus Denaea sp.) and some species of the phoebodonthid (Phoebodus cf. limpidus, Phoebodus gothicus and Th rinacodus tranquilis) and protacrodontid (?Deihim sp.) sharks are reported for the first time from the Moravian Karst Paleozoic sequences in this paper.A relatively large number of microvertebrate remains (ichthyoliths) was obtained during a recent micropaleontological research of the Devonian-Carboniferous boundary interval from the Líšeň Formation, Moravian Karst. Sections were sampled from the late Famennian Middle Palmatolepis gracilis expansa to the early Tournaisian Siphonodella bransoni conodont Zones in bed-by-bed manner. Samples were dissolved in 15% acetic acid and ichthyoliths were hand-picked from the sieved insoluble residues and then studied under a binocular microscope. Preservation of many presented ichthyoliths is excellent, allowing determination on the genus or even species-level. Despite the well preservation, a large number of obtained ichthyoliths were preliminary assigned only to the higher taxonomic units. The ichthyoliths belong to a wide range of taxonomic groups comprising chondrichthyan, sarcopterygian, actinopterygian and acanthodian classes. The class Actinopterygii, chondrichthyan orders Squatinactiformes (Squatinactis sp.) and Ctenacanthiformes, symmoriid shark family Falcatidae (genus Denaea sp.) and some species of the phoebodonthid (Phoebodus cf. limpidus, Phoebodus gothicus and Th rinacodus tranquilis) and protacrodontid (?Deihim sp.) sharks are reported for the first time from the Moravian Karst Paleozoic sequences in this paper

Karstic features in rocks of the Bílá Hora Formation (Turonian, Bohemian Cretaceous Basin) from the Březinka quarry near Letovice

Pseudokarstic features are common in clastic sediments at many places of the Bohemian Cretaceous Basin. Occurrences of karstic features which are naturally linked to calcareous sediments are less usual or rather rare. Probably the most extended is the tinyscale Miskovice Karst near Kutná Hora, where macroforms occur. Karstic features of lesser extent in pseudokarstic caves were documented in the Bohemian Paradise and known are as well from the Tichá Orlice and Svitava rivers valleys. Small-sized occurrence of karstic phenomena were found during recent mapping works in the surrounding of Letovice (W Moravia) in the Březinka quarry near Březová n. S. just above the base of the early Turonian Bílá Hora Formation. The karstic features are of a speleotheme character and are represented mainly by sinter crusts, tubercular sinters, concentric spheroidal aggregates and straws. The occurrence of concentric aggregates is tied to primary breccia cavities and, on the other hand, another karstic features occur mainly in cavities of corrosive character. Based on such observation we preliminary interpret the genesis of the secondary carbonates in two distinct phases. A crystallization of the concentric aggregates was connected with primary cavities environment, which were probably restricted to exogenous influences. Sinters, straws and other karstic features were generated during a second phase, characterized by influence of normal exogenous karstic processes.Pseudokarstic features are common in clastic sediments at many places of the Bohemian Cretaceous Basin. Occurrences of karstic features which are naturally linked to calcareous sediments are less usual or rather rare. Probably the most extended is the tinyscale Miskovice Karst near Kutná Hora, where macroforms occur. Karstic features of lesser extent in pseudokarstic caves were documented in the Bohemian Paradise and known are as well from the Tichá Orlice and Svitava rivers valleys. Small-sized occurrence of karstic phenomena were found during recent mapping works in the surrounding of Letovice (W Moravia) in the Březinka quarry near Březová n. S. just above the base of the early Turonian Bílá Hora Formation. The karstic features are of a speleotheme character and are represented mainly by sinter crusts, tubercular sinters, concentric spheroidal aggregates and straws. The occurrence of concentric aggregates is tied to primary breccia cavities and, on the other hand, another karstic features occur mainly in cavities of corrosive character. Based on such observation we preliminary interpret the genesis of the secondary carbonates in two distinct phases. A crystallization of the concentric aggregates was connected with primary cavities environment, which were probably restricted to exogenous influences. Sinters, straws and other karstic features were generated during a second phase, characterized by influence of normal exogenous karstic processes

Konodontová fauna spodního tournai v Lesním lomu (Brno-Líšeň)

Early Tournaisian was a period of transition between devonian hot and carboniferous cold climate system and therefore crucial in terms of global reconstruction evolution. Early Tournaisian represents a period that follows a detailed studied Hangenberg crisis (late Famenian) and that is connected to glaciation. Based on the study of conodont fauna this article outlines the biostratigraphy of the Lower Tournaisian upper Křtiny limestones situated in the Lesní lom quarry. „Upper“ Křtiny limestones are pale grey mud calciturbidites containing abundant microfauna of conodonts, echinoderms, ostracods, brachiopods, bivalves, bryozoans, ichthyoliths, radiolarians, trilobites and foraminiferas. They are part of the Líšeň Formation which belongs to Paleozoic of Moravian Karst. 8 samples were taken and evaluated from 3 profiles. In total there were determined 22 conodont species belonging to conodont families of Bispathodus, Polygnathus, Pseudopolygnathus and Siphonodella. Following taxons were found: Siphonodella belkai DZIK 1997, Si. carinthiaca SCHÖNLAUB 1970, Si. cf Si. isosticha COOPER 1939, Si. duplicata-jii, Si. jii HASS 1959, Si. lobata BRANSON & MEHL 1934b, Si. obsoleta HASS 1959, Si. sandbergi (M1, M2) KLAPPER 1966, Polygnathus communis communis BRANSON & MEHL 1934b, Po. distortus BRANSON & MEHL 1934b, Po. inornatus BRANSON 1934, Po. purus purus VOGES 1959, Po. spicatus BRANSON 1934, Po. vogesi ZIEGLER 1962, Pseudopolygnathus fusiformis BRANSON & MEHL 1934b, Ps. primus BRANSON & MEHL 1934, Ps. triangulus inaequalis VOGES 1959 and Ps. triangulus triangulus VOGES 1959. Based on the conodont elements the Siphonodella jii and Siphonodella sandbergi zones were distinguished. All profiles but profile 2 belonged to the siphonodellid-polygnathid biofacies, profile 2 belonged to the polygnathid biofacies

Petrophysical signature of the Devonian/Carboniferous boundary interval in the Moravian Karst

The first results of the petrophysical research (gamma-ray spectrometry, magnetic susceptibility, diffuse spectral reflectance) of the Devonian/Carboniferous boundary interval in the southern and middle part of the Moravian Karst demonstrate a good correlation potential of outcrop logging by gamma-ray spectrometry. This method allows us to correlate distinct petrophysical patterns through the different lithofacies developments (Horákov and Hostěnice facies), while magnetic susceptibility and diffuse spectral reflectance failed to show correlatable patterns. The most prominent petrophysical patterns at the sections can be correlated with the polyphase Hangenberg Event.The first results of the petrophysical research (gamma-ray spectrometry, magnetic susceptibility, diffuse spectral reflectance) of the Devonian/Carboniferous boundary interval in the southern and middle part of the Moravian Karst demonstrate a good correlation potential of outcrop logging by gamma-ray spectrometry. This method allows us to correlate distinct petrophysical patterns through the different lithofacies developments (Horákov and Hostěnice facies), while magnetic susceptibility and diffuse spectral reflectance failed to show correlatable patterns. The most prominent petrophysical patterns at the sections can be correlated with the polyphase Hangenberg Event

Redox geochemistry of the red ‘orthoceratite limestone’ of Baltoscandia : Possible linkage to mid-Ordovician palaeoceanographic changes

The orthoceratite limestone of the Ordovician epicontinental sea of Baltoscandia is one of the oldest Phanerozoic examples of pelagic marine red beds (MRBs). Being enriched in authigenic haematite, MRBs are considered to be sensitive palaeoceanographic redox indicators. In this paper, the origin of the reddening of the Ordovician MRBs and its timing and redox conditions were addressed at two sections, and in a drill core in the Kinnekulle area, Sweden, through the application of diffuse reflectance spectroscopy, sedimentary petrology (microfacies and electron microprobe), bulk-rock and in-situ element geochemistry (laser-ablation ICP-MS) and molybdenum stable isotope systematics. Enrichment in haematite (up to ~0.05 wt%) occurred during very early diagenesis under low sedimentation rates (~5 mm/kyr), which is comparable to several examples of Phanerozoic MRBs. The reddening was associated with the mm-scale, in-situ mobility of Fe, Mn, As, Mo and U, due to Fe–Mn redox cycling between primary and secondary minerals and pore water under oxic and suboxic to anoxic conditions; it was not related to significant changes in seawater chemistry. Stratigraphic red-to-grey transitions likely coincided with two mid-Darriwilian global regressions (the so-called Täljsten and at the base of the Gullhögen Formation), likely due to the effects of changing sedimentation rates and sub-bottom redox potentials. The Ordovician MRBs coincided with a positive δ13C excursion during the middle Darriwilian, which is different to MRB examples cited from the Devonian to the Cretaceous age, which frequently coincide with shifts to lower values of δ13C. Although MRBs are believed to show a time-specific occurrence in greenhouse or transitional greenhouse-to-icehouse climatic modes by several authors, our study suggests that causal links between MRBs and global carbon cycle remain unclear