Ladislav Slavík

The Czech Academy of Sciences | AVCR · Institute of Geology, Department of Paleobiology and Paleoecology

The base of the Devonian is defined at the first appearance of graptolite Uncinatograptus uniformis uniformis, with the occurrence of trilobite Warburgella rugulosa rugosa and conodont Caudicriodus woschmidti as the auxiliary indicators. Recently some researchers questioned whether Caudicriodus woschmidti can be an indicator, and proposed Caudicrio...

Nearly 800 of Ordovician to Middle Devonian petrographic slides from the Prague Basin (Barrandian area, Czech Republic) have been inspected for the presence of microboring structures in bioclasts. Traces of microbioerosion are rare in the Ordovician to Lower Devonian of the studied area and are produced almost exclusively by bacteria and fungi on b...

Abstract. Přídolí, the fourth series of the Silurian System, represents an interval of faunal changes, which heralded the middle Palaeozoic transformation of marine ecosystem. Understanding of the faunal changes has been limited by lack of widely applicable correlation markers. Consequently, the Přídolí Series remained undivided formally into stage...

The Global Stratotype Section and Point (GSSP) of the Silurian/Devonian boundary, Lower Devonian Series and Lochkovian Stage was formally placed in 1977 at Klonk, in the Czech Republic, at the first appearance of the graptolite Uncinatograptus uniformis uniformis (Přibyl). However, since then, correlation of this limit has been often hampered in ca...

The Ordovician (∼487 to 443 Ma) ended with the formation of extensive Southern Hemisphere ice sheets, known as the Hirnantian glaciation, and the second largest mass extinction in Earth History. It was followed by the Silurian (∼443 to 419 Ma), one of the most climatically unstable periods of the Phanerozoic as evidenced by several large scale (>5‰...

Climate changes close to the Lochkovian-Pragian Event are still widely discussed. Carbonate δ18O and δ13C and conodont apatite δ18O from medial to distal carbonate ramp sediments were analysed to provide further stable isotope data from the stratotype area in the Prague Basin. The uppermost Silurian to lower Emsian δ18O trends are put into an updat...

The Kačák Event is one of the several prominent Devonian climatic and biotic perturbations with a supra-regional to global extent. Its record can be traced in the litho-and biostratigraphy of uppermost Eifelian-lowermost Givetian strata and with multiple geochemical and geophysical proxies. In southwest Iberia, within southwestern Ossa-Morena Zone...

The Devonian succession of the Prague Synform is characterized by two major lithofacies: shallow-water biodetrital, mostly crinoidal limestones that also include a reefal skeletal accumulation of Pragian age, and a more pelagic facies that is represented mostly by calcisiltites. Among the several Devonian prominent sea-level fluctuations, some can...

The middle Homerian biotic crisis resulted in the almost complete eradication of graptolites. The shale-dominated Kosov Quarry section, central Bohemia, preserves the most complete graptolite record across the crisis in peri-Gondwanan Europe. The pre-extinction graptolite assemblage of the upper lundgreni Biozone, composed of ten species vanished i...

Upper Devonian marine deposits of the Baruunhuurai Terrane in western Mongolia represent island arc settings, which yielded a diverse conodont assemblage of 30 taxa, including species of Ancyrognathus (as well as one new species), Icriodus, Mehlina, Polygnathus and Palmatolepis. Biodiversity analysis of Ancyrognathus, Pelekysgnathus, Mehlina and Ic...

Conodonts from two of the most representative sections in the Prague Synform were studied in search of alternative biostratigraphic markers of the Silurian/Devonian boundary. The Na Požárech and Praha-Radotín sections, with contrasting lithologies, were chosen to study changes in conodont faunas in relation to different carbonate facies – i.e., sha...

Due to the lack of continuous lower to middle Lower Devonian limestone successions, the bases of the Lochkovian, Pragian and Emsian in South China have not been defined in terms of conodont biostratigraphy.The Alengchu section in western Yunnan currently represents one of the most continuous Lochkovian to Lower Emsian limestone sequences in South C...

Sub-Milankovitch rhythmic features in sedimentary records have been reported from throughout geological time. However, their origin remains enigmatic, in particular during so-called greenhouse periods in Earth's history. To better understand such short-term climatic changes, we sampled two 3-m-thick intervals of early Devonian hemipelagic carbonate...

A 50-m-thick section in the Požáry quarry, Prague Syncline (Czech Republic) spanning the upper Silurian (uppermost Ludlow and Přídolí) to the lowermost Devonian (Lochkovian) has been studied using sedimentological and physical stratigraphical (gamma-ray spectrometry) methods combined with conodont biostratigraphy. Conodont data demonstrate the pres...

Red pelagic sediments are relatively common in the Phanerozoic. They are often interpreted as products of sea-bottom oxidation during greenhouse climate showing a conspicuous alternation with black shales and thus carrying important palaeoceanographic information. The Lower Devonian (Pragian) carbonate strata of the Prague Basin, Czech Republic (Pr...

Multiple spectral analysis and statistical techniques such as: Continuous Wavelet Transform, Evolutive Harmonic Analysis, Multi-taper method and Average Spectral Misfit, were used in concert to reach an optimal astronomical interpretation. The Požár-CS section shows distinctly varying sediment accumulation rates. The Lochkovian (essentially equival...

Wenlock-Ludlow boundary beds exposed near Nesvačily in the Prague Synform are documented in terms of their lithology, faunal content, high-resolution record of 19 graptolite species, graptolite biostratigraphy, and conodont record. This is the first time in Bohemia and peri-Gondwanan Europe that a continuous graptolite-bearing section through upper...

Prispevek obravnava podobnosti v razvoju krasa kvartarne karbonatne platforme na otoku San Salvador in devonske karbonatne platforme na platoju Krásná na Moravskem. Za obe območji so značilne jame, katerih nastanek lahko razložimo s "flank margin" modelom in so nastale v območju sladkovodnih leč med obdobji relativno visoke morske gladine, v času r...

Detailed correlation, based on conodont sequences, between middle and upper Lochkovian carbonate successions from two key peri-Gondwanan regions, the Spanish Central Pyrenees and the Prague Synform, is attained for the first time. This correlation facilitates the definition of tie points for further multidisciplinary studies that seek to establish...

High-resolution petrophysical logging magnetic susceptibility measurements (MS) and gamma-ray spectrometry (GRS), supplemented by rock magnetic measurements (anhysteretic and isothermal remanent magnetizations (ARM/IRM), frequency-dependent MS (FDMS)) and MS logs alignment using the dynamic time warping (DTW) algorithm, were constrained by upgraded...

The regional zonation of the Wenlock-Ludlow boundary is established for the Prague Synform using refined data from updated conodont records. The following conodont zones have been recognized in the Prague Synform: the Ozarkodina sagitta sagitta Zone, the Ozarkodina bohemica Interval Zone, the Kockelella crassa Zone, the Kockelella variabilis variab...

In late Pragian and early Emsian strata of the Izvestkovyi Karier – II section of Northeast Asia is found a continuous sequence of representatives of the family Polygnathidae which testify to the synthetic nature of the currently used conodont zonal scales. In this time interval are recognized three phylogenetic lineages of polygnathids: Polygnathu...

The stratigraphic correlation of the Ludfordian in the Prague Synform is summarized using refined biostratigraphic data from updated conodont and graptolite faunal records. The seven graptolite and seven conodont biozones and faunal intervals are correlated. The biozonations are then integrated with the generalized eustatic and carbon isotope curve...

Carbonate successions of the early Lower Devonian (Lochkovian-early Pragian) from the Mindigulovo section (West Zilair Zone, western slope of the South Urals) can be globally correlated using diverse conodont faunas. The number of the documented widespread or cosmopolitan taxa of the Lochkovian and early Pragian age enables the definition of global...

Relatively rich conodont faunas from sections in the Prague Synform (Barrandian area, Czech Republic) include a number of indexes and other important guide conodonts that can be correlated with other regions, especially with Nevada and the Spanish Central Pyrenees. The collation and detailed correlation of conodont data from the Lochkovian in two p...

The effects of the Lau Event on conodont faunas in shallow water environments of the Prague Synform were rather mod-erate in comparison with Gotland. The post-event restoration of conodont diversity following the characteristic post-siluricus faunas with diminished elements and dominated by a long-ranging stock of Delotaxis was gradual and not abru...

Magnetic susceptibility (MS) and gamma-ray spectrometric (GRS) logs of the Basal Chotec event (BCE) close above the Lower-Middle Devonian boundary studied at three different palaeogeographic settings: Barrandian Area (Perigondwanan Perunica terrane; Europe, Czech Republic), Central Great Basin (Laurussia; Nevada, USA) and Zeravshan-Gissar Mountain...

The shale-dominated hemipelagic succession exposed in the southwestern part of the Prague Synform preserves the most complete Ludfordian graptolite record so far encountered from peri-Gondwanan Europe. Four graptolite biozones – the Neocucullograptus inexpectatus, Nc. kozlowskii, Pseudomonoclimacis latilobus–Slovinograptus balticus and Pristiograpt...

A cosmopolitan spathognathodontid taxon "Ancyrodelloides carlsi" is not regarded in this paper as one of the earliestknown representatives of Ancyrodelloides according to former concepts, but is considered as conspicuous member of the genus Lanea. The taxon shows distinct morphological innovation of the upper surface of the Pa element within the La...

High-resolution low-field magnetic susceptibility (MS) logs of the Lower Devonian limestone beds of the Zeravshan-GissarMountain Region (Uzbekistan in Central Asia) and Prague Synform (Barrandian area, Bohemia, Czech Republic, Europe)were stratigraphically correlated using dynamic timewarping (DTW) alignment techniques that are sensitive to local v...

Conodont faunas of the Polygnathoides siluricus Zone (Ludfordian, Ludlow) from shallow-water environments of Bohemia are characterized by relatively high taxonomic diversity that reflects an interval with taxa thriving due to increased nutrient supply in rather stable environments during the pre-Lau Event time, as has been documented globally. Alth...

absTracT. The effectiveness of alignment of magnetic susceptibility (MS) stratigraphic sections by means of the dynamic time warping (DTW) approach was tested with positive results. The DTW is a robust and effective tool for the alignment of the sequential MS data which is particularly sensitive to MS-log patterns, their details, successions, disto...

Variations in non-carbonate impurities trapped in the Lower Devonian limestone stratal successions in the Prague Synform are studied, with particular emphasis on the composition and quantities of fine-mineral grain assemblages. Different assemblages are encountered for the Lochkovian, lower Emsian and Pragian. The Lochkovian (represented by the Loc...

An Emsian-Eifelian carbonate-volcaniclastic sequence in south-western Ossa-Morena Zone (Portugal) was studied in terms of reef fauna, conodont biostratigraphy, macro-and micro-facies and magnetic susceptibility stratigraphy. The results point to a bracketing between the Po. patulus and T. australis conodont biozones (uppermost Emsian – middle-late...

Spectral reflectance (SR) is a relatively novel technique which is used as a proxy for organic carbon and siliciclastic input in carbonate sediments, in particular in core research. This study summarizes results from high-resolution outcrop SR logging of a Lower Devonian distal ramp carbonate section of the Barrandian area, Czech Republic. The SR d...

The redefinition of the lower boundary of a traditional stage by means of a GSSP must be adapted as closely as practicable to the traditional boundary level because divergence between the original sense of the stage concept and name and the new GSSP creates confusing nomenclature. The present GSSP for the lower boundary of the Emsian Stage in the Z...

Occurrences and distribution of extremely scarce eognathodontids do not facilitate reliable correlation across the European regions. The correlation of the traditional early Pragian of the Prague Synform (a part of the classical Barrandian area) and the Spanish Central Pyrenees (section Segre 1) is based on conodont taxa of the Icriodus steinachens...

The current conodont biozonation near the Silurian/Devonian boundary includes problematic biozones and is revised. Global applications of the zonal concepts concerning the current standard conodont zones eosteinhornensis, remscheidensis, detorta, and woschmidti are revised. New correlations are based on conodont faunas from the Požáry section (the...

The Spathognathodontidae until recently have been mostly lumped on the genus Ozarkodina. Separation of Zieglerodina Murphy, Valenzuela-Ríos & Carls, 2004 on the basis of the presence in the transition-series elements of alternation of denticle sizes on an undulose blade that lacks outer ledges has provided many taxa that were formerly included in t...

The assessment of the newly sampled conodont fauna and a review of previous studies on the Lochkovian/Pragian GSSP at Velká Chuchle (Barrandian) revealed evident discrepancies. The GSSP-defining taxon – Eognathodus sulcatus "eosulcatus" – occurs lower in the section than was formerly believed. It is pointed out that the GSSP has been defined on the...

Six Pragian-Emsian boundary sections in the Barrandian area, western of Prague, provided evidence of well detectable entries of Latericriodus fauna probably at the earliest Emsian beds (particularly Latericriodus bilatericrescens gracilis Bultynck). The chance to find icriodontid conodonts increases with latest part of Praha Fm., which is apparentl...

Pragian conodont faunas were studied in the stratotype area of the Pragian Stage, and an alternative proposal for Pragian conodont biozonation is suggested. Conodont faunas obtained from 187 samples taken from 13 sections and localities indicate that the present standard global conodont zonal scale, comprising the sulcatus, kindlei and pireneae zon...

Gamma-ray logs from boreholes in the Middle–Upper Devonian carbonate platform of Moravia display tripartite anomalies at locations, where lithological and biostratigraphic data suggest the occurrence of 4th order sedimentary cycle boundaries. Further, where sedimentary boundaries have been changed by later development of caves (usually phreatic cav...

In a pragmatic test conducted on vertical stratigraphic sections in Quaternary platform limestones of San Salvador Island, The Bahamas, gamma-ray spectrometric (GRS) and magnetosusceptibility (κ) data confirmed that characteristic geophysical patterns are coupled with depositional cycle boundaries. These geophysical patterns appear to develop in th...

SEM analyses of rocks from Blow Hole Cave and The Gulf sections (San Salvador Island, Bahamas) found that ca 90-95% of peloids (and minor parts of other particles and cements) are substantially rebuilt into tiny corpuscles of ovoid, rotund cylindrical or slightly bent shapes (50-80 × 60-120 nm). About 20-30% of them form short and branched chains....

In a practical test using vertical sections in Quaternary carbonate platform sediments (San Salvador Island, Bahamas), the gamma-ray spectrometric (GRS) and magneto- susceptibility (MS) data reveal characteristic patterns in U-Th-Fe variation that are coupled with cycle boundaries. The patterns have existed since the early stages of their formation...

Two Early Devonian sections used for this study display a markedly different facies development and lie on opposite limbs of the central Barrandian synform, in the stratotype area of the Pragian Stage. The present biostratigraphical information based on 18 species with a total of 350 conodont specimens is mostly related to the late Lochkovian and e...

Early Devonian conodont fauna was studied on flanks of the Koneprusy reef in the Certovy schody quarries (Barrandian, Czech Republic). Thirty-two samples were taken from the stratigraphic section and produced more than 400 elements and 13 determined conodont species. Ancyrodelloides delta Zone (upper Lochkovian) and Polygnathus serotinus Zone (Dale...

Jednotlivé sv. mají ISBN Od roč. 1997 nakl.: Prague, Institute of Geology of the Academy of Sciences of the Czech Republic Popsáno podle roč. 2000 Přeloženo z češtiny