Morphology, ontogeny and phenotypic plasticity of the microcrinoid Treocrinus from the Třebotov Limestone (Devonian, Daleje-Třebotov Formation; Barrandian area, Czech Republic)

Late Ludlovian Chitinozoa from the locality “Na Požárech” (Silurian, Prague Basin, Barrandian area, Czech Republic)

The stratigraphic separation diagram (SSD) is an often neglected tool of fault analysis, which assists with the interpretation of both the fault‐surface geometry and the mechanism of faulting. As the SSD needs to evaluate displacement or separation along the fault, this particular method can be used only in areas with well‐documented stratigraphic sequences. This paper presents details of some common patterns obtained when using SSDs and also discusses some real examples of two apparently similar faults found in the Barrandian area in the Czech Republic. Although both the Prague and the Tachlovice faults in the Barrandian area seem to be of the same character (the same strike, remarkable stratigraphic separation, similar localization in the Prague Synform), the SSDs of these two faults demonstrate the difference in fault surface geometries and consequently a very distinct mechanism of origin. The Tachlovice Fault is one of the main thrusts in the Prague Synform. It has ramp‐flat geometry and is associated with fault‐related folds. The Prague Fault, on the other hand, was formed later, after the initial folding, and belongs to a group of steep translatory faults. It is shown how SSDs are practical, effective tools for the analysis of these types of faults and associated stratigraphies without the need of 3D seismics or boreholes. Copyright © 2010 John Wiley & Sons, Ltd.

The calceolide coral Calceola sandalina (Linné, 1771) has been observed in the Acanthopyge Limestone (Choteč Formation, Eifelian) in the Koněprusy area, Czech Republic. Its presence in the Barrandian area indicates absence of significant palaeogeographic barriers restricting the distribution of this tetracoral in the Middle Devonian. Association of Calceola with a taxonomically diverse ribbed brachiopod faunas attests for two different types of environment on the Koněprusy submarine elevation during deposition of the Acanthopyge Limestone. Calceola-bearing beds represent a high-energy reefal environment different from somewhat deeper and calmer environment characterized by smooth-shelled, small to medium sized spire-bearing brachiopods.

Laboratory-scale experimental burning of three facial types of Devonian limestones from the Barrandian area (Czech Republic) revealed their suitability for production of natural hydraulic lime and/or natural cement of variable degrees of hydraulicity. Although employed as a raw material for ordinary Portland cement at present, all these limestones must be blended to achieve the optimum composition required for ordinary Portland cement clinker. However, if burnt in their natural state (i.e. without any further addition of SiO2, Al2O3 and/or Fe2O3), and by using a sufficiently coarse grained batch, they exhibit favourable content of newly formed hydraulic phases. These are controlled not only by overall mineralogical/chemical composition of a raw material, but also by burning conditions, specifically by peak temperature and its duration. Prevalent dicalcium silicate (larnite) plus some minor calcium aluminosilicates (gehlenite) or aluminoferrites (brownmillerite) form due to solid state reactions between homogeneously distributed non-carbonate fraction (silica minerals, clay minerals, feldspars) in micritic carbonate groundmass.

The morphogroups of small agglutinated foraminifera from the Devonian carbonate complex of the Prague Synform, (Barrandian area, Czech Republic)

Rich foraminiferal assemblages from the Lower/Middle Devonian parastratotype at the Prastav Quarry near Prague (Barrandian area, Czech Republic) were studied in detail and correlated with foraminifers from seven sections of the same age from the Barrandian area. Forty-five taxa of foraminifers were recognized in the Lower/Middle Devonian boundary beds. Distribution of foraminiferal taxa in sections and their comparison with the respective paleoecological data show good potential for Devonian foraminifers to be used as paleoecological indicators. Psammosphaera cava, Pseudoastrorrhiza cf. irregularis, Saccorhiza pseudospiralis and Thuramminoides sphaeroidalis could tolerate unfavorable ecological conditions. Psammosphaera and Hemisphaerammina occurred in higher energy environments, while Ammodiscus ex gr. incertus required a low-energy environment. Morphometric variability of Ammodiscus ex gr. incertus (test size, number of whorls, size of proloculus) may indicate the presence of megalospheric and microspheric forms. Microspheric forms prevailed in unstable, higher energy environments. Multivariate analyses of foraminiferal assemblages enable differentiation of four types of foraminiferal assemblages whose spatial distribution corresponds well with lithofacies distribution. Changes in successive assemblages mirror shifts from low-energy to higher energy environments around the Lower/Middle Devonian boundary (= Basal Chotec Event).

This contribution briefly summarizes the history of research, modes of preservation and stratigraphic distribution of 51 trilobite and five agnostid taxa from the Barrandian area, for which the early developmental stages have been described.

Microboring organisms — an overlooked Early-Mid Palaeozoic marine ecosystem: Case study from the Prague Basin (Czech Republic)

Magnetostratigraphy susceptibility of the Přı́dolian–Lochkovian (Silurian–Devonian) GSSP (Klonk, Czech Republic) and a coeval sequence in Anti-Atlas Morocco

Feeding traces related to shells from the Prague Basin, Czech Republic (Tremadocian to early Darriwilian, Ordovician)

Lower Palaeozoic of the Barrandian area (Czech Republic) - a review

Several sites of the Middle Cambrian Jince and Buchava formations (Barrandian area, Czech Republic), showing features of Burgess Shale-type preservation, yielded diverse ichnofossils adjacent to non- or poorly biomineralized body fossils of arthropods, and less commonly, acrotretid brachiopods. Based on morphology, Gordia-like, Cochlichnus-like, Planolites-like, Treptichnus-like and Pilichnus-like traces occur with “nondescript” bioturbation. Ethologically, the Gordia-like and Cochlichnus-like traces are interpreted as single-use traces of feeding on microbial halo. Treptichnus-like and Pilichnus-like traces suggest later feeding systems associated also with feeding on microbial halo, and Planolites-like traces likely represent a fortuitous feature.

Cooksonia bohemica Schweitzer (= Aberlemnia bohemica (Schweitzer) Sakala, Pšenička et Kraft) from Přídolí strata of the Barrandian area in the Czech Republic is revised, and its morphology is documented in detail. The holotype bears sporangia that, although reniform, do not possess a slit that would allow valvate opening as assumed in earlier studies. Its axes do not show consistent shortening of segments towards the distal portion of the plant as is typical for Aberlemnia Gonez et Gerrienne. The axes contain tubular structures interpreted here as cells of conducting tissues. Masses of subtriangular trilete spores with equatorial crassitudo and finely microgranulate sculpture are of the Ambitisporites type. Cooksonia bohemica is compared with all species of Cooksonia Lang described previously. Additionally, comparisons are made with the related genus Aberlemnia. Based on studies of the type material of both taxa, we suggest retaining the species in Cooksonia. Cooksonia bohemica is differentiated from other taxa based on a combination of branching pattern, sporangial shape, and spore morphology. The remains are interpreted to be the sporophyte of an early land plant referable to tracheophytes based on the presence of vascular strands in its axes. A general radiation of cooksonioids away from a core region around the Rheic Ocean is proposed for the Silurian–Devonian transition.

The first occurrence of fenestrate bryozoans is reported from the Acanthopyge Limestone (Eifelian) in the Koněprusy area of the Czech Republic. Fragmented zoaria have been identified in lightgrey crinoidal-limestone rich with brachiopods, corals, and stromatoporoids. Several species of fenestrates are evident, but poor preservation and fragmentation of zoaria allow only approximate taxonomic determination. The fenestrates, Fenestella sp., Laxifenestella (?) sp., Hemitrypa sp., Polyporella sp., Ptylopora sp., and Reteporina sp., are illustrated and briefly described. The presence of fenestrates has a great palaeoenvironmental significance. Fenestrates together with brachiopods, stromatopoids, and corals indicate a high-energy reef environment on the Koněprusy submarine elevation in the upper Eifelian. Morphology of fenestrates and high morphological disparity of brachiopods are remarkably similar to the faunas of the Pragian age in the Koněprusy area suggesting a similar reef environment. The upper Eifelian age of the locality is evidenced by conodonts of the Tortodus kockelianus Zone.

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 parallel sections in the Požáry quarries, together with biostratigraphic control of additional data from several (incomplete) sections with changing facies development, is the basis for a new detailed regional biozonal scale for the Lochkovian in the Prague Synform. The new subdivision follows, with modification, the global threefold conodont subdivision of the Lochkovian. Data from the Prague Synform enable further detailed subdivision of the lower, middle and upper Lochkovian into small‐scale units. The conodont distribution shows a large proportional discrepancy between the late Lochkovian elsewhere; the conodont record in the latest Lochkovian in the Prague Synform area, which appears to be rather restricted and requires further discussion. Copyright © 2012 John Wiley & Sons, Ltd.