Middle Devonian parathuramminid and earlandiid foraminifers from shallow marine carbonates of the Carnic Alps (Austria)

2018 ◽  
Vol 92 (3) ◽  
pp. 336-372
Author(s):  
Daniel Vachard ◽  
Karl Krainer ◽  
Alexander Mörtl
Keyword(s):  
Middle Devonian ◽  
Depositional Environment ◽  
Microbial Mats ◽  
Late Devonian ◽  
Tidal Channel ◽  
Carnic Alps ◽  
Shallow Marine ◽  
Marine Carbonates ◽  
Peritidal Facies ◽  
Marine Facies

AbstractThe Devonian of the Carnic Alps (Austria) is developed in different facies. The shallow marine facies is up to 1200 m thick. The Feldkogel Limestone of the Polinik Formation, >330 m thick, was dated as Eifelian–Late Devonian. The Feldkogel Limestone at Mount Polinik is developed in a peritidal facies composed of subtidal, intertidal, and supratidal deposits. Subtidal sediments are represented by dark grayAmphiporalimestone and intertidal deposits by laminated and partly bioturbated grainstone and packstone, ostracode wackestone to packstone, and locally intercalated intraclast breccias documenting tidal channel fills. Laminated microbial mats (stromatolites) formed in a supratidal depositional environment. Grainstone and packstone contain abundant unilocular parathuramminid foraminifers. This latter group encompasses a diversified assemblage of ivanovellids, parathuramminids, uralinellids, and irregularinoids; some earlandiids are also present. They are dated herein as late Eifelian–early Givetian. These foraminifers provide a more precise systematics of these taxa, which often have not been studied for more than half a century. The taxonomic problems of their assignment to foraminifers, pseudo-foraminifers, calcitarcha, thaumatoporellaceans, volvocaleans, or other algae are also discussed. Several taxa are emendated: Parathuramminida, Parathuramminoidea, Irregularinoidea, Eovolutinidae, Ivanovellidae, Parathuramminidae, Uralinellidae,Ivanovella,Elenella,Neoarchaesphaera,Parathurammina,Bykovaella,Uralinella, andParacaligella. The new taxa are:Ivanovella reitlingeraen. sp.,Elenella polinikensisn. sp.,Uralinella sabirovin. sp., andRadiosphaerella poyarkovin. sp.

scholarly journals Paleotemperature record of the Middle Devonian Kačák Episode

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thomas J. Suttner ◽  
Erika Kido ◽  
Michael M. Joachimski ◽  
Stanislava Vodrážková ◽  
Monica Pondrelli ◽  
...  
Keyword(s):  
Middle Devonian ◽  
Seawater Temperature ◽  
Sea Surface ◽  
Time Interval ◽  
Marine Biota ◽  
Carnic Alps ◽  
Climate Conditions ◽  
Shallow Marine ◽  
Low Latitudes ◽  
Mean Sea Surface

AbstractThe Middle Devonian Epoch, ~ 393–383 million years ago, is known for a peak in diversity and highest latitudinal distribution of coral and stromatoporoid reefs. About 388 million years ago, during the late Eifelian and earliest Givetian, climax conditions were interrupted by the polyphased Kačák Episode, a short-lived period of marine dys-/anoxia associated with climate warming that lasted less than 500 kyr. Reconstruction of the seawater temperature contributes to a better understanding of the climate conditions marine biota were exposed to during the event interval. To date, conodont apatite-based paleotemperatures across the Eifelian–Givetian boundary interval have been published from Belarus, France, Germany and North America (10–36° S paleolatitude). Here we provide new δ18Oapatite data from the Carnic Alps (Austria, Italy) and the Prague Synform (Czech Republic). For better approximation of the paleotemperature record across the Kačák Episode, a latitude-dependent correction for Middle Devonian seawater δ18O is applied. Because δ18Oapatite data from shallow marine sections are influenced by regional salinity variations, calculated mean sea surface temperatures (SST) are restricted to more open marine settings (22–34° S paleolatitude). Water temperatures reach ~ 34 °C in the Prague Synform and ~ 33 °C in the Carnic Alps and suggest that SSTs of the southern hemisphere low latitudes were ~ 6 °C higher than previously assumed for this time interval.

scholarly journals Non-marine palaeoenvironment associated to the earliest tetrapod tracks

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Martin Qvarnström ◽  
Piotr Szrek ◽  
Per E. Ahlberg ◽  
Grzegorz Niedźwiedzki
Keyword(s):  
Marine Environment ◽  
Middle Devonian ◽  
Depositional Environment ◽  
Marine Biota ◽  
Shallow Marine ◽  
Terrestrial Locomotion ◽  
Ephemeral Lakes ◽  
Environmental Association ◽  
Additional Support

Abstract Opinions differ on whether the evolution of tetrapods (limbed vertebrates) from lobe-finned fishes was directly linked to terrestrialization. The earliest known tetrapod fossils, from the Middle Devonian (approximately 390 million years old) of Zachełmie Quarry in Poland, are trackways made by limbs with digits; they document a direct environmental association and thus have the potential to help answer this question. However, the tetrapod identity of the tracks has recently been challenged, despite their well-preserved morphology, on account of their great age and supposedly shallow marine (intertidal or lagoonal) depositional environment. Here we present a new palaeoenvironmental interpretation of the track-bearing interval from Zachełmie, showing that it represents a succession of ephemeral lakes with a restricted and non-marine biota, rather than a marginal marine environment as originally thought. This context suggests that the trackmaker was capable of terrestrial locomotion, consistent with the appendage morphology recorded by the footprints, and thus provides additional support for a tetrapod identification.

scholarly journals Age, microfacies and depositional environment of the Middle to Late Paleocene shallow-marine carbonates in the Sirt Basin of Libya (Upper Sabil Formation): “Are Intisar domal structures pinnacle reefs?”

Facies ◽  
2021 ◽  
Vol 67 (4) ◽  
Author(s):  
A. Vršič ◽  
H.-J. Gawlick ◽  
F. Schlagintweit ◽  
E. Machaniec ◽  
M. Gharsalla
Keyword(s):  
Depositional Environment ◽  
Planktonic Foraminifera ◽  
Carbonate Ramp ◽  
Larger Benthic Foraminifera ◽  
Shallow Marine ◽  
Late Paleocene ◽  
Marine Carbonates ◽  
Domal Structure ◽  
Sirt Basin

AbstractIn the central-eastern Sirt Basin, enigmatic Intisar domal structures host significant hydrocarbon accumulations. These structures have been commonly interpreted as pinnacle reefs/bioherms occurring in the open-marine basinal environment. Generally, pinnacle reefs/bioherms are mainly characterized by in situ carbonates. The current study challenges the Intisar pinnacle reef/bioherm model by examining one of the domal structures in terms of biostratigraphy, microfacies and depositional environment. These structures were dated using larger benthic foraminifera, which yielded a Middle to Late Paleocene age (Selandian–Early Thanetian). Thirteen microfacies types representing different carbonate ramp environments ranging from outer ramp to inner ramp, were defined. Outer ramp deposits have been observed adjacent to the domal structure, represented mainly by wackestone with small benthic and planktonic foraminifera. The outer ramp deposits are most likely isochronous to the domal structures. The lower part of the domal structures is composed mainly of foraminiferal–algal–echinodermal packstones. The upper part is characterized by foraminiferal–algal–echinodermal packstones with intercalated microbialite–coral boundstones. The euphotic inner ramp deposits are preserved on the crest of the domal structure, consisting of grainstone and packstone rich in Glomalveolina. As a result of this study, the Intisar domal structures are seen as erosional relics of a carbonate ramp and no evidence for pinnacle reef/bioherm model was found.

scholarly journals <i>Wangshangkia</i>, a new Devonian ostracod genus from Dushan of Guizhou, South China

2018 ◽  
Vol 37 (1) ◽  
pp. 341-346
Author(s):  
Junjun Song ◽  
Yiming Gong
Keyword(s):  
New Species ◽  
South China ◽  
Depositional Environment ◽  
New Genus ◽  
Late Devonian ◽  
Shallow Marine ◽  
The Family ◽  
Two New Species

Abstract. Wangshangkia, a new genus of Ostracoda, from the Late Devonian in Dushan of Guizhou, South China, is described. This genus belongs to the family Bairdiocyprididae Shaver, 1961 and includes two new species, i.e. Wangshangkia dushaniensis and W. bailouiensis. The new genus is characterized by a wide ventral carina with radial striae. It is reported from the Famennian of South China and disappeared just below the Devonian-Carboniferous boundary. Wangshangkia is essentially a benthic crawler and is restricted to the shallow-marine depositional environment with a low hydrodynamic condition.Wangshangkia: urn:lsid:zoobank.org:act:34BF01D4-D202-492D-8E27-BC508EF7EFFBW. dushaniensis: urn:lsid:zoobank.org:act:D267C362-7510-4D19-996B-EA1848D7D025W. bailouiensis: urn:lsid:zoobank.org:act:FE988AA0-7363-4D9E-A5AB-1526C8DBCDD9

Modern and Holocene microbial mats and associated microbially induced sedimentary structures (MISS) on the southeastern coast of Tunisia (Mediterranean Sea)

2020 ◽  
pp. 1-21
Author(s):  
Rached Lakhdar ◽  
Mohamed Soussi ◽  
Rachida Talbi
Keyword(s):  
Spatial Distribution ◽  
High Frequency ◽  
Depositional Environment ◽  
Microbial Mats ◽  
Coastal Environment ◽  
Tidal Dynamics ◽  
Very High Frequency ◽  
Intertidal Zones ◽  
Sedimentary Structures ◽  
Very High

Abstract On the southeastern Tunisian coastline, very diverse living microbial mats colonize the lower supratidal and intertidal zones, and locally may extend into the upper infratidal zone. The interaction between the benthic cyanobacteria and their siliciclastic substratum leads to the development of several types of microbially induced sedimentary structures (MISS). The mapping of the microbial mats has allowed the identification of the types of MISS that characterize the different segments of the coastal environment. The modern microbial mats have been compared with those recorded at the top of the Holocene deposits, which are composed of biodegraded microbial black mats alternating with white laminae made of clastic and evaporitic sediments, indicative of very high frequency cycles of flood and drought. A hypothetic profile showing their occurrences along the different areas bordering the coastline is proposed as a guide for the reconstruction of the ancient depositional environment. The roles of tidal dynamics, storms, and climate in controlling their genesis and spatial distribution, are discussed and highlighted. The modern MISS of southeastern Tunisia are compared with their equivalents that are well documented through the different geological eras.

Sign in / Sign up

Export Citation Format

Share Document