scholarly journals Two cycads Nilssonia mirovanae sp. nov. and Pseudoctenis babinensis J.Kvaček from the Cenomanian of the Bohemian Cretaceous Basin (the Czech Republic) as indicators of water stress in the palaeoenvironment

2020 ◽  
Vol 76 (2) ◽  
pp. 315-324
Author(s):  
Jana Čepičková ◽  
Jiří Kvaček
Keyword(s):  
Czech Republic ◽  
Water Stress ◽  
Late Cretaceous ◽  
The Czech Republic ◽  
Characteristic Features ◽  
Bohemian Cretaceous Basin

Nilssonia mirovanae sp. nov. is described from the Late Cretaceous Cenomanian of the Bohemian Cretaceous Basin. It comes from the best-exposed portion of the Peruc-Korycany Formation, in the Pecínov quarry, west of Prague, the Czech Republic. Although preserved only as a fragment of a pinna, it clearly shows haplocheilic stomata. In this paper, we compare N. mirovanae with Pseudoctenis babinensis J.Kvaček from the same horizon. These two cycads have similar adaptations for surviving water stress: thick cuticles and sunken stomata, characteristic features among gymnosperms indicating adaptation to xeromorphic plants, cuticle analysis, Late Cretaceousdrought.

Turonian marine amniotes from the Bohemian Cretaceous Basin, Czech Republic

2013 ◽  
Vol 151 (1) ◽  
pp. 183-198 ◽  
Author(s):  
BENJAMIN P. KEAR ◽  
BORIS EKRT ◽  
JOSEF PROKOP ◽  
GEORGIOS L. GEORGALIS
Keyword(s):  
Czech Republic ◽  
Late Cretaceous ◽  
Sea Turtles ◽  
Diverse Range ◽  
The Czech Republic ◽  
Bohemian Cretaceous Basin ◽  
Recent Attention

AbstractDespite being known for over 155 years, the Late Cretaceous marine amniotes of the Bohemian Cretaceous Basin in the Czech Republic have received little recent attention. These fossils are however significant because they record a diverse range of taxa from an incompletely known geological interval: the Turonian. The presently identifiable remains include isolated bones and teeth, together with a few disarticulated skeletons. The most productive stratigraphical unit is the Lower–Middle Turonian Bílá Hora Formation, which has yielded small dermochelyoid sea turtles, a possible polycotylid plesiosaur and elements compatible with the giant predatory pliosauromorphPolyptychodon. A huge protostegid, together with an enigmatic cheloniid-like turtle,Polyptychodon-like dentigerous components, an elasmosaurid and a tethysaurine mosasauroid have also been found in strata corresponding to the Middle–Upper Turonian Jizera Formation and Upper Turonian – Coniacian Teplice Formation. The compositional character of the Bohemian Cretaceous Basin fauna is compatible with coeval assemblages from elsewhere along the peri-Tethyan shelf of Europe, and incorporates the globally terminal Middle–Upper Turonian occurrence of pliosauromorph megacarnivores, which were seemingly replaced by mosasauroids later in the Cretaceous.

scholarly journals A new specimen of Araucaria fricii from the early Coniacian of the Bohemian Massif, Central Europe

2021 ◽  
Vol 77 (2) ◽  
pp. 282-286
Author(s):  
Jiří Kvaček
Keyword(s):  
Czech Republic ◽  
Central Europe ◽  
Bohemian Massif ◽  
Type Material ◽  
Massif Central ◽  
The Czech Republic ◽  
First Occurrence ◽  
Bohemian Cretaceous Basin ◽  
Cone Scale

A specimen of Araucaria fricii is described from the upper part of the Teplice Formation in the Bohemian Cretaceous Basin. It extends the first occurrence of A. fricii from the mid-Coniacian back to the early Coniacian. Found in the Radovesice locality near Kučlín in the northern part of the Czech Republic, it is characterised by a deltoid cone scale complex with a centrally placed seed. It is compared to the type material of A. fricii from the mid-Coniacian Březno Formation and other European Cretaceous species of Araucaria. The taphonomy and palaeoecology of A. fricii is briefly discussed.

scholarly journals Nannofossil record across the Cenomanian-Coniacian interval in the Bohemian Cretaceous Basin and Tethyan foreland basins (Outer Western Carpathians), Czech Republic

2012 ◽  
Vol 63 (3) ◽  
pp. 201-217 ◽  
Author(s):  
Lilian Švábenická
Keyword(s):  
Czech Republic ◽  
Black Shales ◽  
Western Carpathians ◽  
High Latitudes ◽  
Foreland Basins ◽  
Mutual Correlation ◽  
The Czech Republic ◽  
Outer Western Carpathians ◽  
First Occurrence ◽  
Bohemian Cretaceous Basin

Nannofossil record across the Cenomanian-Coniacian interval in the Bohemian Cretaceous Basin and Tethyan foreland basins (Outer Western Carpathians), Czech Republic Nannofossil biostratigraphy and mutual correlation was worked out for the Cenomanian-Coniacian deposits of the Bohemian Cretaceous Basin (BCB) and Outer Western Carpathians (OWC) in the territory of the Czech Republic. Similar assemblages of the BCB and from sediments deposited on the SE slopes of West European Platform, Waschbergždánice-Subsilesian Unit, OWC support the hypothesis that the two areas were connected by a sea way (nowadays the Blansko trough). The nannoflora of the Silesian Unit, OWC show more afinity to high latitudes as is documented by the presence of Marthasterites furcatus in the Lower Turonian, UC6b and UC7 Zones. Turonian and Coniacian deep-water flysch sediments of the Silesian Unit and Magura Group of Nappes provide nannofossils on rare occassions. Strongly atched nannofossils dominated by W. barnesiae from Cenomanian black shales of the BCB are comparable to those of the Silesian Unit and reflect a similar shallow nearshore sea. In the BCB, uppermost Cenomanian is marked by the last occurrence (LO) of Axopodorhabdus albianus and first occurrence (FO) of Quadrum intermedium (6 and 7 elements) and lowermost Turonian by a sudden quantitative rise in nannoflora and by the FO Eprolithus octopetalus. First Eiffellithus eximius and thus the base of the UC8 Zone was recorded in the upper part of ammonite Zone Collignoniceras woollgari in the lower Middle Turonian. Lithastrinus grillii is the stratigraphically youngest nannofossil species in this region and indicates the uppermost Coniacian. In the OWC, the Albian-Cenomanian boundary was recorded in the Silesian Unit and is marked by the LO Crucicribrum anglicum and FO Prediscosphaera cretacea and Corollithion kennedyi in the uppermost Albian. The Turonian-Coniacian boundary found both in the BCB and Waschberg-Ždánice-Subsilesian Unit, OWC is indicated by the FO Broinsonia parca expansa and by the base of the interval with common Marthasterites furcatus. In both areas, events were found closely below the FO inoceramid species Cremnoceramus waltersdorfensis. The Coniacian-Santonian boundary interval (Waschberg-Ždánice-Subsilesian and Foremagura Units, OWC) is indicated by Lithastrinus grillii occasionally accompanied by Lucianorhabdus ex gr. cayeuxii, Hexalithus sp. and Arkhangelskiella specillata.

scholarly journals The negotiation position amid member states of the EU

2012 ◽  
Vol 52 (No. 3) ◽  
pp. 133-137
Author(s):  
P. Michálek ◽  
P. Rymešová ◽  
L. Müllerová ◽  
H. Chamoutová ◽  
K. Chamoutová
Keyword(s):  
Czech Republic ◽  
Topographic Map ◽  
Present Climate ◽  
Arbitrary Group ◽  
Member States ◽  
The Czech Republic ◽  
Relative Closeness ◽  
Characteristic Features ◽  
Answering Questions ◽  
The Eu

The European integration process is very important and it has been paid attention to for the last 15 years. The abstract deals with the negotiation field and position in the structure of the current expanded EU. For better orientation in this equivocal situation, a modern cartography method of relationship in the arbitrary group called dynamic sociometry was used. The method is based on classical sociometry Morena and furthermore it uses the instrument of fuzzy set, typology and structural analysis. The output of this method is a sociomap. The map holds information on the relative closeness or the distance of individual elements, their configuration but also some quality information. The graphic chart is similar to a topographic map. In our case, the sociomap was created from the data of foreign business among the member countries. The following analysis of the sociomap we detected and described characteristic features of the analysed group. It consists of formal and informal links in the group, the role and the position of each member within the group, the structure and relations in the group. In the concrete, we attained data to answer the questions about the present climate in interrelationships in the EU, which means the relationships among the members as the whole entities but also the relationships separately among members themselves. The position analysis of the Czech Republic in the system of the created sociomaps was considered as very important. According to the allocation of the Czech Republic in sociomaps, we easily defined the position of the state, the closest partners for negotiation, and also the possible problem relations which might complicate the negotiation in the EU. From the resultant sociomaps, we also tried to determine the sociometric star, i.e. the leader of the European Community. We anticipated that it would be rather an aggregation of several states than an individual state. The contribution focuses on the negotiation field and position in the structure of the current expanded EU. The sociomap created using foreign business data of member states gives the bases for answering questions about present climate in interrelationships in the EU which means the relationships between the members as whole entities but also the relationships separately between the members themselves.

scholarly journals Late Cretaceous environments and communities as recorded at Chrtníky (Bohemian Cretaceous Basin, Czech Republic)

2006 ◽  
pp. 43-79 ◽  
Author(s):  
J. Žítt ◽  
R. Vodrážka ◽  
L. Hradecká ◽  
M. Svobodová ◽  
K. Zágoršek
Keyword(s):  
Czech Republic ◽  
Late Cretaceous ◽  
Bohemian Cretaceous Basin

scholarly journals New records of Vertigo moulinsiana (Gastropoda: Vertiginidae) and notes on its distribution and habitats in the Czech Republic

2006 ◽  
Vol 5 ◽  
pp. 14-17
Author(s):  
Luboš Beran
Keyword(s):  
Czech Republic ◽  
River Basin ◽  
New Records ◽  
Large Area ◽  
The Czech Republic ◽  
Spring Fens ◽  
Southern Moravia ◽  
Bohemian Cretaceous Basin ◽  
White Carpathians

Vertigo moulinsiana (Dupuy, 1849) was found in 2003–2005 in Northern Bohemia (Czech Republic) at 11 sites. All these sites are situated on floodplains of smaller streams in a sandstone area. The known occurrence of this endangered relict in the Czech Republic is concentrated in three areas – a large area of Bohemian Cretaceous Basin, a floodplain near villages Břežany and Božice (Dyje River Basin) in Southern Moravia and small, isolated, treeless fens in the White Carpathians (Bílé Karpaty Mts.). The principal habitats where V. moulinsiana lives in the Czech Republic are sedge marshes, Typha swamps, reed swamps (with Carex spp.), alder carrs (also with Carex spp.) and tufa-forming spring fens.

scholarly journals Preliminary Revision of the Palynological Collection of Professor Blanka Pacltová – A Significant Collection of Cenomanian Microflora Housed at the National Museum, Prague

2019 ◽  
Vol 75 (2) ◽  
pp. 141-152
Author(s):  
Eduardo Barrón ◽  
Jiří Kvaček ◽  
Jiřina Dašková
Keyword(s):  
Czech Republic ◽  
National Museum ◽  
The Czech Republic ◽  
Pollen Types ◽  
1960S And 1970S ◽  
Bohemian Cretaceous Basin ◽  
The 1960S ◽  
Angiosperm Pollen ◽  
Long Term Preservation

A preliminary revision of the palynological collection of Professor Blanka Pacltová was carried out considering samples from the middle Cenomanian of the Peruc-Korycany Formation, the basal most member of the Bohemian Cretaceous Basin (the Czech Republic). This collection is mainly composed of slides with palynological residues for light microscope study, which were mounted in the 1960s and 1970s. This work presents an evaluation of the state of preservation of this collection, taking into account the presence of ancient angiosperm pollen types. High percentage of preparations is affected by degradation of glycerine jelly and their remounting is necessary. The present study additionally suggests a methodology for curation of this collection with the objective of long-term preservation.

Formation of high-transmisivity zones in the facies transition in the Bohemian Cretaceous Basin (Czech Republic) 

2021 ◽  
Author(s):  
Jiri Stary ◽  
Jana Schweigstillova ◽  
Jiri Bruthans
Keyword(s):  
Czech Republic ◽  
Hydrochloric Acid ◽  
Marine Sponges ◽  
Carbonate Content ◽  
Rock Outcrops ◽  
The Czech Republic ◽  
High Carbonate ◽  
Bohemian Cretaceous Basin ◽  
High Carbonate Content ◽  
Facies Transition

<p>The Bohemian Cretaceous Basin (BCB) is the most important hydrogeological structure in the Czech Republic, with large sources of groundwater. The origin of high-transmissivity zones is poorly understood in many BCB areas. The doyen of Czech hydrogeology prof. Hynie described some of the largest springs to be of karst origin and he attributed the most permeable areas to facies transition between shallow-water sandstones and deep-water marlstones. In many BCB areas with large springs we can find thin sandstones and siltstones layers with high carbonate content even in stratigraphical levels corresponding with aquifers.</p><p>Research is focused on Vysoké Mýto and Ustí synclines in BCB, 125 km east of Prague in the Czech Republic. Overall 167 rock samples were taken from borehole cores and rock outcrops in this area, the most from Jizera and Bílá Hora formations. Cores were taken from intervals where: (i) high carbonate content was expected, (ii) conduits and enlarged fractures were observed at outcrops and in wells, (iii) inflows to boreholes were determined by well logging. Calcium carbonate content was determined by calcimetry in cores. Cores were leached in 10 % hydrochloric acid to observe the degree of subsequent disintegration. Polished sections were prepared from selected cores and Ca, Si, Na, K, Al content was automatically mapped by SEM-EDS to visualize the calcium, silica, feldspar and clay mineral distribution in cores.</p><p>Leaching in hydrochloric acid is an accelerated simulation of natural processes of dissolution by acidic solutions (Kůrková et al. 2019). In many aquifers in BCB there are thin calcite-rich layers with quartz sand which disintegrates after leaching calcite. Leaching of the samples in acid results in the decrease of sample strength, sometimes to their disintegration. Leaching experiments showed that the carbonate content is not the only controlling factor in the karstification process.</p><p>In sediments with detrital quartz admixture in central or western parts of the BCB the total disintegration mostly occurs between 35-50% CaCO<sub>3</sub> content depending on insoluble material content (Kůrková et al. 2020). In contrast, in the eastern part of the BCB, a degree of disintegration above 10% is documented in only 7% of the studied samples. In sediments with diagenetically precipitated cement from marine sponges even calcite content as high as 80% may not be sufficient for material to disintegrate after leaching. Disintegration occurs mainly along fractured zones where rock is heavily fractured.  </p><p>It seems that the increased content of microcrystalline silica cementy in sandy limestones and calcareous sandstones (spongolites) of the studied area has a fundamental influence on the higher cohesion and resistance of rocks to dissolution. Cause for increased cohesion is the specific spatial distribution of  microcrystalline silica, which bound the quartz grains together or formed a foam-like supporting structure in fine calcite-rich deposits.</p><p> </p><p>The research was financially supported by the GA ČR 19-14082S.</p><p> </p><p>References:</p><p>Kůrková I., Bruthans J., Balák F., Slavík M., Schweigstillová J., Bruthansová J., Mikuš P., Grundloch J. (2019): Factors controlling evolution of karst conduits in sandy limestone and calcareous sandstone (Turnov area, Czech Republic). Journal of Hydrology: 574: 1062-1073.</p>

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