Conodont stratigraphy and conodont biofacies of the shallow-water Kuh-e-Bande-Abdol-Hossein section (SE Anarak, Central Iran)

ABSTRACTThe Late Ordovician–Early Silurian succession in Jämtland includes the marine Kogsta Siltstone, which is unconformably overlain by the shallow-water Ede Quartzite that grades into the open-marine Berge Limestone. A Hirnantia shelly fauna dates the uppermost Kogsta Siltstone as Hirnantian, and shelly fossils indicate an Aeronian age for the Berge Limestone. Biostratigraphically highly diagnostic conodonts of the early-middle Aeronian Pranognathus tenuis Zone provide the first firm date of the Upper Ede Quartzite and the lowermost Berge Limestone. The Lower Ede Quartzite has not yielded fossils, but sedimentological data suggest it to be of Hirnantian age and reflect the glacio-eustatic low-stand. The contact between the Lower and Upper Ede Quartzite, here taken to be the Ordovician–Silurian boundary, appears to be an unconformity associated with a stratigraphic gap that at least includes the Rhuddanian Stage. The biostratigraphically important conodonts Pranognathus tenuis, Kockelella? manitoulinensis, and Pranognathus siluricus are recorded from Sweden for the first time, and these and other conodonts are used for correlations with coeval units in Europe and North America. In a regional review of Aeronian conodont faunas, three intergrading, apparently depth-related, conodont biofacies are recognised, the Jämtland conodonts representing the one characteristic of the shallowest water.

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COMMENTS ON “STRATIGRAPHIC DISTRIBUTION OF SHALLOW-WATER BENTHIC FORAMINIFERA FROM THE LOWER CRETACEOUS TAFT FORMATION, CENTRAL IRAN (YAZD BLOCK), WITH EVIDENCE FOR THE IMPORTANCE OF HIATUSES” BY GHEIASVAND, M. ET AL. [ANNALES DE PALÉONTOLOGIE, 2020, 154 (3), 102399] AND RELATED PAPERS

Acta Palaeontologica Romaniae ◽

10.35463/j.apr.2022.01.01 ◽

2021 ◽

pp. 3-8

Author(s):

FELIX SCHLAGINTWEIT

Keyword(s):

Shallow Water ◽

Benthic Foraminifera ◽

Lower Cretaceous ◽

Central Iran ◽

Migration Patterns ◽

Larger Benthic Foraminifera ◽

Multidisciplinary Study ◽

Potential Index

Gheiasvand et al. (2020) use the two larger benthic foraminifera species Simplorbitolina manasi Ciry & Rat and Mesorbitolina parva (Douglass) (Orbitolinidae) as upper Aptian “potential index fossils” for parts of the Taft Formation in Central Iran. This age assignment is accompanied by changes to well-established orbitolinid biozona-tions (e.g. occurrence of Praeorbitolina in the late Aptian) with far-reaching implications. These data were also used in a later “multidisciplinary study” (Gheiasvand et al., 2021) for isotopic correlations (e.g., location of OAE`s), delimitation of palaeobiogeographic faunal provinces and related migration patterns. It is shown herein that the taxa identified as S. manasi and M. parva belong to Iraqia simplex Henson and Palorbitolina lenticularis (Blumenbach) respectively documenting a lower and not an upper Aptian age. This revised age and the different taxononomic inventory do not question all results obtained by Gheiasvand et al. (2020, 2021), but provide a revised basis interpretation.

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Quantitative analysis of Pennsylvanian shallow-water conodont biofacies, Utah and Colorado

Geological Society of America Special Papers - Conodont Biofacies and Provincialism ◽

10.1130/spe196-p233 ◽

1984 ◽

pp. 233-250 ◽

Cited By ~ 5

Author(s):

Steven G. Driese ◽

Timothy R. Carr ◽

David L. Clark

Keyword(s):

Quantitative Analysis ◽

Shallow Water ◽

Conodont Biofacies

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Carboniferous conodont biostratigraphy

Geological Society London Special Publications ◽

10.1144/sp512-2020-38 ◽

2020 ◽

pp. SP512-2020-38

Author(s):

James E. Barrick ◽

Alexander S. Alekseev ◽

Silvia Blanco-Ferrera ◽

Natalia V. Goreva ◽

Keyi Hu ◽

...

Keyword(s):

Shallow Water ◽

Deep Water ◽

Global Distribution ◽

High Quality ◽

Conodont Biostratigraphy ◽

Conodont Biofacies ◽

Extinction Event ◽

Water Facies

AbstractCarboniferous conodont biostratigraphy comprises regional zonations that reflect the paleogeographic distribution of taxa and distinct shallow-water and deep-water conodont biofacies. Some species have a global distribution and can effect high quality correlations. These taxa are incorporated into definitions of global Carboniferous chronostratigraphic units. A standard global Carboniferous zonation has not been developed. The lowermost Mississippian is zoned by Siphonodella species, except in shallow-water facies, where other polygnathids are used. Gnathodus species radiated during the Tournaisian and are used to define many Mississippian zones. A late Tournaisian maximum in diversity, characterized by short-lived genera, was followed by lower diversity faunas of Gnathodus species and carminate genera through the Viséan and Serpukhovian. By the late Viséan and Serpukhovian, Lochriea provides better biostratigraphic resolution. Shallow-water zonations based on Cavusgnathus and Mestognathus are difficult to correlate. An extinction event near the base of the Pennsylvanian was followed by the appearance of new gnathodid genera: Rhachistognathus, Declinognathodus, Neognathodus, Idiognathoides, and Idiognathodus. By the middle of the Moscovian, few genera remained: Idiognathodus, Neognathodus and Swadelina. During the middle Kasimovian and Gzhelian, only Idiognathodus and Streptognathodus species were common. Near the end of the Gzhelian, a rediversification of Streptognathodus species extended into the Cisuralian.

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Gigantism in Late Devonian ammonoids from Chahriseh (Central Iran)

Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen ◽

10.1127/njgpa/2020/0925 ◽

2020 ◽

Vol 297 (3) ◽

pp. 287-294

Author(s):

Dieter Korn ◽

Vachik Hairapetian ◽

Hossein Gholamalian

Keyword(s):

New Species ◽

Water Temperature ◽

Shallow Water ◽

Central Europe ◽

North Africa ◽

Sea Water ◽

Central Iran ◽

Late Devonian ◽

Post Mortem ◽

Large Size

Gigantic representatives of the clymeniid genera Hoevelia and Protactoclymenia (Late Devonian ammonoids) with conch sizes up to 50 cm occur in small numbers in shallow-water carbonates at Chahriseh (Central Iran). Comparison with other occurrences of gigantic clymeniids (Central Europe, North Africa) suggests that taphonomic reasons rather than latitudinal effects with differences in sea water temperature and oxygen availability are responsible for this gigantism. The large size of the ammonoids at Chahriseh is interpreted as local phenomenon caused by accumulation of post-mortem drifted specimens. The new species Hoevelia megalomanica is described.

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