Depositional controls on Early Cambrian microbial carbonates from the Montagne Noire, southern France

1998 ◽  
Vol 89 (3) ◽  
pp. 135-143 ◽  
Author(s):  
J. Javier Álvaro ◽  
Emmanuelle Vennin ◽  
Daniel Vizcaïno
Keyword(s):  
Lower Cambrian ◽  
Southern France ◽  
Microbial Structures ◽  
Subaerial Exposure ◽  
Open Sea ◽  
Montagne Noire ◽  
Constructed Self ◽  
Depositional Controls ◽  
First Time ◽  
Open Shelf

AbstractLower Cambrian shallow-water carbonates enclosing microbial structures are documented for the first time from the upper Lastours Member of the Montagne Noire (southern France). Microbial organisms constructed self-supported boundstones resulting in the formation of exclusively microbial-accreted buildups, which exhibit three main types of non-skeletal microbialites: planar stratiform stromatolites, dome-shaped stromatolites and nonlaminated (thrombolitic) biostromes. In addition, thrombolitic boundstones display four distinct microbial microstructures: clotted andRenalcis-like forms, branching bushy forms, clusters of unbranching straight filaments and crustose forms.The upper member of the Lastours Formation records an upward transition from a shalydominant open shelf to a protected shelf environment bounded by a surface representing a major subaerial exposure. Initially, at the inception of the highstand systems tract, flat stratiform stromatolites formed on open sea subtidal shaly substrates, while stacked domal stromatolites developed in peritidal areas which record subaerial exposure. In contrast, prograding shoal barriers of the transgressive systems tract favoured the establishment of thrombolitic boundstones in protected (back-shoal) environments.

scholarly journals Schizocrania (Brachiopoda, Discinoidea): taxonomy, occurrence, ecology and history of the earliest epizoan lingulate brachiopod

2016 ◽  
Vol 72 (3-4) ◽  
pp. 225-238 ◽  
Author(s):  
Michal Mergl ◽  
Lucie Nolčová
Keyword(s):  
Trophic Structure ◽  
Ventral Valve ◽  
Dorsal Valve ◽  
Early Devonian ◽  
Sea Floor ◽  
Open Sea ◽  
History Of ◽  
Barrandian Area ◽  
Floating Objects ◽  
First Time

The lingulate brachiopod Schizocrania (Trematidae, Discinoidea) is reviewed. Ptychopeltis is definitively synonymized with Schizocrania, because new data indicate that convexity of the shell, profile of the anterior margin commissure, density of the dorsal valve costellation, ornamentation of the ventral valve and shape of the pedicle notch are worthless for separation of these genera. Four Ordovician species of Schizocrania are reported from the Barrandian area: S. multistriata (Darriwilian), S. hornyi (Sandbian), S. incola (Sandbian) and the new species S. equestra sp. nov. (Katian). Occurrence of Schizocrania striata is confirmed for the first time around the S/D boundary in the Barrandian area. Schizocrania has a wide geographic range with mid-Ordovician to early Devonian occurrences in Laurentia, Avalonia, West Gondwana and the Silurian occurrence in Baltica. Schizocrania was the earliest lingulate brachiopod adhering to floating objects in an open sea (both living cephalopods and their empty drifting shells), but it was highly opportunistic, and used any vacant hard surface on the sea floor (conulariids, strophomenid brachiopods, trilobites) as a suitable substrate for settlement of the larva. Decline of the genus coincided with disappearance of planktic graptolites, and might have been caused by competition of rapidly evolving planktic dacryoconarids, increased predation pressure, and rebuilding of the trophic structure in the early Devonian seas.

scholarly journals Synanthedon mesiaeformis (Herrich-Schäffer) new to the Czech Republic and to Spain (Lepidoptera: Sesiidae)

2008 ◽  
Vol 56 (5) ◽  
pp. 141-146 ◽  
Author(s):  
Zdeněk Laštůvka ◽  
Aleš Laštůvka
Keyword(s):  
Czech Republic ◽  
Close Contact ◽  
Morphological Characters ◽  
Habitat Requirements ◽  
Specific Population ◽  
The Czech Republic ◽  
Southern France ◽  
History Of ◽  
First Time ◽  
The Town

Synanthedon mesiaeformis (Herrich-Schäffer, 1846) has been found in the Czech Republic and in Spain for the first time. The species was found in the south-easternmost part of the Czech Republic, near the town of Břeclav (faunistic quadrat 7267) in May 2008. The holes and pupae were found only in one, solitary growing group of trees about 20 years old. This finding place lies at a distance of more than 250 km from the localities in SW Hungary and about 550 km from the localities in eastern Poland. In June 2008, the species was found also in alders growing in the flat river alluvium on gravel sands between La Jonquera and Figueres in northern Catalonia. This locality is in a close contact with the fin­ding places near Perpignan and Beziers in southern France. The diagnostic morphological characters and bionomics of this species are briefly summarized and figured. The history of its distribution research is recapitulated and the causes of its disjunct range are discussed as follows. The present disjunct range represents a residual of the former distribution over the warmer and moister postglacial period; landscape modifications and elimination of solitary alder trees as „weeds“ from the 18th up to the mid-20th century in large areas of Europe; narrow and partly unknown habitat requirements and specific population ethology; an insufficient level of faunistic investigations in several parts of sou­thern and eastern Europe.

scholarly journals PALEOPROSTŘEDÍ VE SPODNÍM BADENU NA SEVERNÍM OKRAJI BRNA (DIVIŠOVA ČTVRŤ)

2018 ◽  
Vol 25 (1-2) ◽  
Author(s):  
Pavla Tomanová Petrová ◽  
Slavomír Nehyba ◽  
Karel Diviš ◽  
Šárka Hladilová ◽  
Růžena Gregorová ◽  
...  
Keyword(s):  
Point Of View ◽  
Coarse Grained ◽  
Open Sea ◽  
First Time ◽  
Littoral Area

Lower Badenian sediments were studied on the locality Hvozdíkova at the Diviš district, Brno. There were interpreted 4 lithofacies of Neogene (Lower Badenian) sediments (lithofacies M1, M2, Sl, and SGl). Occurrence of basal Lower Badenian clastics is connected with existence of coarse-grained delta (foreset). Overlying pelites document pelagic sedimentation of open sea. Garnet dominates in assemblage of heavy translucent minerals.Rich assemblages of foraminifers, molluscs, spines of echinoids, ostracods and shark fauna were discovered in sediments. Diversified assemblages are dominated by plankton specimens. Species Orbulina suturalis Brön., Praeorbulina glomerosa circularis (Blow) and Globigerinoides bisphericus Todd. indicate the Lower Badenian age.From the point of view of the shark fauna diversity the locality Hvozdíkova is unique; shark fauna is very rare in Lower Badenian clays, and the genera of Squaliolus and Paraetmopterus are identified for the first time. Oysters – especially species Neopycnodonte navicularis (Brocchi) – dominate in Lower Badenian sediments. Small gastropods (for example Cancellaria sp., ?Tornus sp., Rissoa sp., Alvania sp.) probably represent fossils reworked from shallow littoral area. 

Horizontal Moisture Transport Dominates the Regional Moistening Patterns in the Arctic

2020 ◽  
Vol 33 (16) ◽  
pp. 6793-6807
Author(s):  
Tiina Nygård ◽  
Tuomas Naakka ◽  
Timo Vihma
Keyword(s):  
Sea Ice ◽  
Atmospheric Pressure ◽  
Moisture Transport ◽  
Reanalysis Data ◽  
The Arctic ◽  
Surface Evaporation ◽  
Open Sea ◽  
Sea Ice Decline ◽  
First Time ◽  
Limited Period

AbstractAlong with the amplified warming and dramatic sea ice decline, the Arctic has experienced regionally and seasonally variable moistening of the atmosphere. Based on reanalysis data, this study demonstrates that the regional moistening patterns during the last four decades, 1979–2018, were predominantly shaped by the strong trends in horizontal moisture transport. Our results suggest that the trends in moisture transport were largely driven by changes in atmospheric circulation. Trends in evaporation in the Arctic had a smaller role in shaping the moistening patterns. Both horizontal moisture transport and local evaporation have been affected by the diminishing sea ice cover during the cold seasons from autumn to spring. Increases in evaporation have been restricted to the vicinity of the sea ice margin over a limited period during the local sea ice decline. For the first time we demonstrate that, after the sea ice has disappeared from a region, evaporation over the open sea has had negative trends due to the effect of horizontal moisture transport to suppress evaporation. Near the sea ice margin, the trends in moisture transport and evaporation and the cloud response to those have been circulation dependent. The future moisture and cloud distributions in the Arctic are expected to respond to changes in atmospheric pressure patterns; circulation and moisture transport will also control where and when efficient surface evaporation can occur.

scholarly journals Early Late Cambrian Trilobites OF Australo-Sinian Aspect From The Montagne Noire, Southern France

Palaeontology ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 599-632 ◽  
Author(s):  
John H. Shergold ◽  
Raimund FEIST ◽  
Daniel Vizcaino
Keyword(s):  
Southern France ◽  
Late Cambrian ◽  
Montagne Noire ◽  
Early Late
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