Ostracods and lithofacies of the Middle/Upper Devonian boundary stratotype (Puech de la Suque, Montagne Noire, France)

2007 ◽  
Vol 178 (4) ◽  
pp. 293-304 ◽  
Author(s):  
Jean-Georges Casier ◽  
Alain Préat
Keyword(s):  
Upper Devonian ◽  
Environmental Setting ◽  
Storm Wave ◽  
Montagne Noire ◽  
Stratotype Section ◽  
Storm Deposits

Abstract This paper discusses ostracods and their environmental setting close to the Givetian/Frasnian boundary in the Puech de la Suque Global Stratotype Section and Point. The ostracod fauna belongs exclusively to the Eifelian mega-assemblage and is largely dominated by Podocopina instars. Consequently, the majority of the 33 species recognised and illustrated is described in open nomenclature. The abundance of instars also indicates that most of beds are related to storm deposition. The composition of the fauna suggests a regression in the late Givetian followed by a transgression at the beginning of the Frasnian. Only one ostracod assemblage collected in the upper part of the section indicates a deeper setting below the storm wave base. Eight taxa disappeared in two steps near the Givetian / Frasnian boundary, probably in relation to the Frasnes Event. The sedimentological analysis confirms that the section is constituted principally of storm deposits and reveals in addition the presence of numerous reddish hardgrounds highlighting an important condensation of the sequence.

scholarly journals A CARBONATE RAMP EVOLUTION IN THE TRANSITION FROM THE APULIA PLATFORM TO THE IONIAN BASIN DURING EARLY TO LATE CRETACEOUS (NW GREECE)

2018 ◽  
Vol 40 (1) ◽  
pp. 53
Author(s):  
K. Getsos ◽  
F. Pomoni-Papaioannou ◽  
A. Zelilidis
Keyword(s):  
Sea Level ◽  
Late Cretaceous ◽  
Facies Analysis ◽  
Carbonate Ramp ◽  
Time Interval ◽  
Storm Wave ◽  
Lowermost Part ◽  
Storm Deposits ◽  
Homoclinal Ramp ◽  
Apulia Platform

Facies analysis of Cretaceous carbonate sequences from the external and central Ionian zone revealed a homoclinal ramp model of evolution. During Berriasian to Valanginian, the carbonate ramp was differentiated to an inner-mid and outer ramp environment, which corresponded to the external and central Ionian zone, respectively, while the main inner ramp environment is assumed that was located in the Pre-Apulian zone. The external Ionian zone (inner-mid ramp) is characterized by muds tones-wackes tones with fragmented echinoderms, bivalves, radiolarians and rare aptychus considered to be deposited below the fairweather wave base (FWWB). Locally, thin graded storm deposits intervene, indicating deposition above the storm weather wave base (SWB). Minor occurrences of packs tonesgrainstones, with fragmented echinoderms, calcareous algae, tubiphytes, lagenid foraminifera and rare ooids occur, as well, considered to be deposited at the lowermost part of the inner ramp, near the constantly agitated fairweather wave base (FWWB). The central Ionian zone (outer ramp) is mainly characterized by mudstones-wackestones with abundant radiolarians and rare calpionellids and calcispheres, considered to be deposited below the storm wave base (SWB). No talus or breccias deposits were observed, during the mentioned time interval, in any part of the studied area. From Hauterivian to Turonian, continual sea-level rise, led to establishment of outer ramp environment in the external Ionian zone, over the previous inner-mid ramp, and outer ramp-basin environment, over the previous outer ramp, in the central Ionian zone. The transition from shallower to deeper conditions is characterized by an overall deposition of mudstones-wackestones with abundant radiolarians rooted in pure micrite. 

Devonian

1992 ◽  
Vol 13 (1) ◽  
pp. 57-66 ◽  
Author(s):  
B. J. Bluck ◽  
J. C. W. Cope ◽  
C. T. Scrutton
Keyword(s):  
Lower Devonian ◽  
Quaternary System ◽  
Upper Devonian ◽  
Type Locality ◽  
System Boundary ◽  
Red Sandstone ◽  
Stratotype Section ◽  
Lacustrine Facies ◽  
Selection Of ◽  
Upper Boundary

AbstractThe Devonian System was the first pre-Quaternary system to have its base established at an internationally ratified Global Stratotype Section and Point (GSSP). The base of the System was defined at the base of the Monograptus uniformis Biozone at Klonk in Czechoslovakia (McLaren 1977). The upper boundary of the System is fixed by the base of the Carboniferous, which has been recently ratified in a GSSP at La Serre, Herault, France, at a point coincident with the first appearance of the conodont Siphonodella sulcata.Series. GSSPs have now been designated to define the bases of the Middle and Upper Devonian Series (that of the Lower Devonian being automatically defined by the System boundary).Stages. Consequent upon the selection of a Czech type section for the basal boundary stratotype of the System, the Germanic stages for the lowest parts of the Devonian were no longer appropriate and Lochkovian and Pragian stages have now been formally defined with stratotypes ratified by the I.U.G.S.Devon, the nomenclatorial type locality for the Devonian System (Sedgwick & Murchison 1839) is a region of great tectonic complexity and has not provided suitable sections on which to base international correlations. However, the rocks are frequently richly fossilferous and firm correlations can now be established with the intensively studied developments of the Devonian in Belgium and Germany.Northwards from Devon are found large tracts of the predominantly fluviatile and lacustrine facies which characterizes the Old Red Sandstone. Correlation between the marine Devonian rocks of southwest England and the

Quantification of outlines in Frasnian (Upper Devonian) platform conodonts

1986 ◽  
Vol 23 (8) ◽  
pp. 1214-1222 ◽  
Author(s):  
Gilbert Klapper ◽  
C. T. Foster Jr.
Keyword(s):  
Discriminant Analysis ◽  
Related Species ◽  
Visual Discrimination ◽  
Close Agreement ◽  
Upper Devonian ◽  
Angle Function ◽  
Orientation Function ◽  
Montagne Noire ◽  
Taxonomic Methods

The outline of the platform in Pa elements of conodont genera such as Palmatolepis is commonly one of the most heavily weighted taxonomic characters. But a taxonomy based only on visual discrimination of Pa elements of Frasnian species of Palmatolepis has resulted in widespread misidentification. Although their Pa elements can be confused, Palmatolepis subrecta, Palmatolepis hassi, and related species from the Frasnian of the Montagne Noire and Iowa can be separated consistently by use of features displayed by other elements of the apparatus, especially the Pb and M elements. To determine if significant differences exist among the Pa elements of these multielement species, digitized outlines of the Pa elements were analyzed using an orientation function similar to the tangent-angle function of F. L. Bookstein. A multielement classification based on the Pb and M elements was tested by a discriminant analysis of the outlines of the Pa elements. The results show that there is close agreement between the two procedures and that systematic differences exist among the Pa elements of groupings based on the Pb and M elements. Unquestionably, quantification of the outlines of platform conodonts will substantially improve taxonomic methods, with consequent enhancement of biostratigraphy.

scholarly journals Bioerosion traces and borings in the Upper Devonian vertebrate remains from the Holy Cross Mountains, Poland Bioerosion in fish remains

2021 ◽  
Author(s):  
Piotr Szrek ◽  
Patrycja G. Dworczak ◽  
Olga Wilk
Keyword(s):  
Shallow Water ◽  
Cross Section ◽  
Water Environment ◽  
Trace Fossils ◽  
Upper Devonian ◽  
Holy Cross Mountains ◽  
Shallow Tunnels ◽  
Shallow Water Environment ◽  
Storm Wave ◽  
Fish Remains

Among the hundreds of collected Devonian vertebrate macrofossils in the Holy Cross Mountains, placoderms dominate and provide data on their morphology, distribution and taphonomy. So far 17 out of more than 500 studied specimens have revealed bones with surfaces covered by sediment-filled trace fossils. The traces have been made on the vertebrate remains before their final burial. The borings, oval in cross-section, include dendroidal networks of shallow tunnels or short, straight or curved individual scratches and grooves, which frequently create groups on the both sides of the bones. ?Karethraichnus isp. from Kowala and ?Osteocallis isp. from Wietrznia are the oldest record of these ichnogenera. Sedimentological clues indicate a shallow water environment, probably from the slope below the storm wave base.

Upper Devonian (Frasnian) stromatactis-bearing mud mounds, western Alberta, Canada: reef framework dominated by peloidal microcrystalline calcite

2019 ◽  
Vol 89 (9) ◽  
pp. 833-848
Author(s):  
Kai Zhou ◽  
Brian R. Pratt
Keyword(s):  
Dynamic Balance ◽  
Upper Devonian ◽  
Time Interval ◽  
Fair Weather ◽  
Cyanobacterial Mats ◽  
Mud Mounds ◽  
Storm Wave ◽  
Reef Type ◽  
Metabolic Activities ◽  
Destructive Processes

ABSTRACT Two well-preserved mud mounds, approximately 50 m thick, in the Mount Hawk Formation (Upper Devonian, Frasnian) in western Alberta provide an unparalleled opportunity to study the microstructure of this reef type in detail for this time interval. This reveals that they are composed dominantly of peloidal sediments—more than a quarter of mud mound volume—along with dense micrite, particulate micrite, bioclasts, and stromatactis cavities. Five types of peloids are differentiated: bacterial, cyanobacterial, bioclastic, intraclastic, and pseudo-peloids. Bacterial peloids were generated by bacterial metabolic activities with possibly some contribution from organomineralization in areas within spicular networks. Three subtypes of cyanobacterial peloids are distinguished based on whether they are physically reworked calcified filaments, aggregates of calcified coccoids, or precipitated within stromatolite-forming cyanobacterial mats or biofilms. Bioclastic peloids are fully micritized fragments of skeletons and shells. Intraclastic peloids are eroded fragments of early-lithified matrix. Pseudo-peloids represent artifacts of poorly preserved sponge spicular networks reflecting the interplay between dissolution of spicules and organomineralization. The distribution of the various peloid types shows specificity in different microfacies. They prove to be valuable paleoecological indicators, and taken together suggest that the mud mounds accreted within the photic zone above storm wave base but below the fair-weather wave base, during deposition of a transgressive and perhaps highstand systems tracts. They are the products reflecting a dynamic balance between constructional versus destructive processes. Bacterial peloids combined with dense micrite constitute the framework, which in turn makes up close to 40% of the mud mounds. This indicates that microbial activities are responsible for the early-indurated framework. The onset of bacterial peloid formation in the bedded sediment immediately underlying the mud mounds further demonstrates that it may have been a necessary precursor to mud-mound initiation. Bacterial peloids appear to characterize most Paleozoic and Mesozoic reefal mud mounds as an essential framework element.

Upper Devonian conodonts from the Timan-Pechora region, Russia, and correlation with a Frasnian composite standard

1996 ◽  
Vol 70 (1) ◽  
pp. 131-152 ◽  
Author(s):  
Gilbert Klapper ◽  
Alexei V. Kuz'Min ◽  
Nonna S. Ovnatanova
Keyword(s):  
North America ◽  
Western Australia ◽  
Distribution Patterns ◽  
Upper Devonian ◽  
Correlation Diagram ◽  
Western Canada ◽  
Conodont Zonation ◽  
Montagne Noire

A Frasnian composite standard provides a refined scaling for the thirteen-fold conodont zonation first developed in the Montagne Noire, France, but since replicated in North America, Australia, and now the Timan-Pechora region of Russia. Zones 4–13 are identifiable in seven cores from the Ukhta area of southern Timan and a core from the Bagan Field of the Khoreyver Basin. Scaling of the zones through graphic correlation demonstrates the diachronism in different sections of the bases of many conodont species, including those of zonally definingPalmatolepis.This can be effectively shown in a correlation diagram scaled to a composite standard based on graphic correlation, whereas it is obscured by the assumption of synchronism inherent in conventional zonal correlation charts.Newly described species occurring in the Timan-Pechora region and elsewhere areOzarkodina nonaginta, Ancyrognathus amplicavus, Mesotaxis johnsoni, Palmatolepis amplificata, P. mucronata, P. ormistoni, andP. timanensis.A number of other species described earlier from the region also occur outside Russia, mainly in Canada and Australia. Distribution patterns in the composite standard indicate close faunal connections between the Timan-Pechora, western Canada, and Western Australia.

Late Devonian conodonts define the precise horizon of the Frasnian–Famennian boundary at Cinquefoil Mountain, Jasper, Alberta

1995 ◽  
Vol 32 (11) ◽  
pp. 1825-1834 ◽  
Author(s):  
K. Wang ◽  
H. H. J. Geidsetzer
Keyword(s):  
Upper Devonian ◽  
Late Devonian ◽  
Southeastern Margin ◽  
Carbonate Slope ◽  
Montagne Noire ◽  
Depositional Setting ◽  
First Time

Conodonts from carbonate slope sediments of the Ronde Member at Cinquefoil Mountain near Jasper, Alberta, have constrained the Frasnian–Famennian boundary in the Upper Devonian for the first time in Canada. Based on conodont Palmatolepis species, the Frasnian–Famennian boundary has been precisely identified in this section at the base of a tempestite bed (20 cm thick), 14 m above the base of the Ronde Member and directly below a prominent oncolite bed (65 cm thick). Recognized standard conodont zones are the Upper rhenana–linguiformis (or Montagne Noire Zone 13), the Lower triangularis, and the Middle triangularis zones. Conodonts exhibit a mixed Palmatolepis–Polygnathus–Icriodus biofacies, supporting the paleogeographic interpretation of this site as an upperslope depositional setting along the southeastern margin of the paleo-Jasper Basin.

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