Paleolatitudes of Late Triassic radiolarian cherts from Argolis, Greece: Insights on the paleogeography of the western Tethys

2015 ◽  
Vol 417 ◽  
pp. 476-490 ◽  
Author(s):  
Giovanni Muttoni ◽  
Paola Tartarotti ◽  
Marco Chiari ◽  
Chiara Marieni ◽  
Daniel Rodelli ◽  
...  
Keyword(s):  
Late Triassic ◽  
Western Tethys

scholarly journals The calcareous nannofossil <i>Prinsiosphaera</i> achieved rock-forming abundances in the latest Triassic of western Tethys: consequences for the δ<sup>13</sup>C of bulk carbonate

2013 ◽  
Vol 10 (5) ◽  
pp. 7989-8025 ◽  
Author(s):  
N. Preto ◽  
C. Agnini ◽  
M. Rigo ◽  
M. Sprovieri ◽  
H. Westphal
Keyword(s):  
Global Ocean ◽  
Late Triassic ◽  
Calcareous Nannofossils ◽  
Calcareous Nannofossil ◽  
Western Tethys ◽  
Carbonate Sedimentation ◽  
History Of ◽  
Calcareous Plankton ◽  
Inorganic Carbon Cycle

Abstract. The onset of pelagic biomineralization marked a milestone in the history of the long term inorganic carbon cycle: as soon as calcareous nannofossils became major limestone producers, the pH and supersaturation state of the global ocean were stabilized (the so-called Mid Mesozoic Revolution). But although it is known that calcareous nannofossils were abundant already by the end of the Triassic, no estimates exist on their contribution to hemipelagic carbonate sedimentation. With this work, we estimate the volume proportion of Prinsiosphaera, the dominant Late Triassic calcareous nannofossil, in hemipelagic and pelagic carbonates of western Tethys. The investigated Upper Triassic lime mudstones are composed essentially of microspar and tests of calcareous nannofossils, plus minor bioclasts. Prinsiosphaera became a significant component of lime mudstones since the late Norian, and was contributing up to ca. 60% of the carbonate by the late Rhaetian in periplatform environments with hemipelagic sedimentation. The increasing proportion of Prinsiosphaera in upper Rhaetian hemipelagic lime mudstones is paralleled by a increase of the δ13C of bulk carbonate. We interpreted this isotopic trend as related to the diagenesis of microspar, which incorporated respired organic carbon with a low δ13C when it formed during shallow burial. As the proportion of nannofossil tests increased, the contribution of microspar with low δ13C diminished, determining the isotopic trend. We suggest that a similar diagenetic effect may be observed in many Mesozoic limestones with a significant, but not yet dominant, proportion of calcareous plankton.

scholarly journals The calcareous nannofossil <i>Prinsiosphaera</i> achieved rock-forming abundances in the latest Triassic of western Tethys: consequences for the <i>δ</i><sup>13</sup>C of bulk carbonate

2013 ◽  
Vol 10 (9) ◽  
pp. 6053-6068 ◽  
Author(s):  
N. Preto ◽  
C. Agnini ◽  
M. Rigo ◽  
M. Sprovieri ◽  
H. Westphal
Keyword(s):  
Global Ocean ◽  
Late Triassic ◽  
Calcareous Nannofossils ◽  
Calcareous Nannofossil ◽  
Western Tethys ◽  
Carbonate Sedimentation ◽  
History Of ◽  
Calcareous Plankton ◽  
Inorganic Carbon Cycle

Abstract. The onset of pelagic biomineralization was a milestone in the history of the long-term inorganic carbon cycle: as soon as calcareous nannofossils became major limestone producers, the pH and supersaturation state of the global ocean were stabilized (the so-called mid-Mesozoic revolution). But although it is known that calcareous nannofossils were abundant already by the end of the Triassic, no estimates exist on their contribution to hemipelagic carbonate sedimentation. With this work, we estimate the volume proportion of Prinsiosphaera, the dominant late Triassic calcareous nannofossil, in hemipelagic and pelagic carbonates of western Tethys. The investigated Upper Triassic lime mudstones are composed essentially of microspar and tests of calcareous nannofossils, plus minor bioclasts. Prinsiosphaera had become a significant component of lime mudstones since the late Norian, and was contributing up to ca. 60% of the carbonate by the late Rhaetian in periplatform environments with hemipelagic sedimentation. The increasing proportion of Prinsiosphaera in upper Rhaetian hemipelagic lime mudstones is paralleled by an increase of the δ13C of bulk carbonate. We interpreted this isotopic trend as related to the diagenesis of microspar, which incorporated respired organic carbon with a low δ13C when it formed during shallow burial. As the proportion of nannofossil tests increased, the contribution of microspar with low δ13C diminished, determining the isotopic trend. We suggest that a similar diagenetic effect may be observed in many Mesozoic limestones with a significant, but not yet dominant, proportion of calcareous plankton.

scholarly journals Photosymbiosis in Late Triassic scleractinian corals from the Italian Dolomites

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11062
Author(s):  
Katarzyna Frankowiak ◽  
Ewa Roniewicz ◽  
Jarosław Stolarski
Keyword(s):  
Coefficient Of Variation ◽  
Isotope Composition ◽  
Scleractinian Corals ◽  
Regular Growth ◽  
Late Triassic ◽  
Western Tethys ◽  
Growth Increments ◽  
Algal Symbiosis ◽  
Growth Bands ◽  
Zooxanthellate Corals

During the Carnian, oligotrophic shallow-water regions of the western Tethys were occupied by small, coral-rich patch reefs. Scleractinian corals, which already contributed to the formation of the reef structure, owed their position most probably to the symbiosis with dinoflagellate algae (zooxanthellae). Using microstructural (regularity of growth increments) and geochemical (oxygen and carbon stable isotopes) criteria of zooxanthellae symbiosis, we investigated whether this partnership was widespread among Carnian scleractinians from the Italian Dolomites (locality Alpe di Specie). Although corals from this locality are renowned from excellent mineralogical preservation (aragonite), their skeletons were rigorously tested against traces of diagenesis Irrespective of their growth forms, well preserved skeletons of corals from the Dolomites, most frequently revealed regular growth bands (low values of coefficient of variation) typical of modern zooxanthellate corals. Paradoxically, some Carnian taxa (Thamnasteriomorpha frechi and Thamnasteriomorphasp.)with highly integrated thamnasterioid colonies which today are formed exclusively by zooxanthellate corals, showed irregular fine-scale growth bands (coefficient of variation of 40% and 41% respectively) that could suggest their asymbiotic status. However, similar irregular skeletal banding is known also in some modern agariciids (Leptoseris fragilis) which are symbiotic with zooxanthellae. This may point to a similar ecological adaptation of Triassic taxa with thamnasterioid colonies. Contrary to occasionally ambiguous interpretation of growth banding, all examined Carnian corals exhibited lack of distinct correlation between carbon (δ13C range between 0.81‰ and 5.81‰) and oxygen (δ18O values range between −4.21‰ and −1.06‰) isotope composition of the skeleton which is consistent with similar pattern in modern zooxanthellates. It is therefore highly likely, that Carnian scleractinian corals exhibited analogous ecological adaptations as modern symbiotic corals and that coral-algal symbiosis that spread across various clades of Scleractinia preceded the reef bloom at the end of the Triassic.

scholarly journals Early-Middle Jurassic stepwise deepening in the transitional facies belt between the Adriatic Carbonte Platform Basement and Neo-Tethys open shelf in northeastern Montenegro evidenced by new ammonoid data from the early Late Pliensbachian (Lavinianum Zone)

2021 ◽  
pp. 1-1
Author(s):  
Martin Djakovic ◽  
Hans-Jürgen Gawlick ◽  
Milan Sudar
Keyword(s):  
Middle Jurassic ◽  
General Trend ◽  
Carbonate Platform ◽  
Late Triassic ◽  
Western Tethys ◽  
Tethys Realm ◽  
Shallow Subtidal ◽  
Marine Influence ◽  
Early Late ◽  
Open Shelf

New ammonoid data prove an early Late Pliensbachian deepening event above the ?Late Hettangian-Sinemurian shallow-subtidal gray-reddish micro-oncoidal-foraminifera grainstone facies and the ?Early Pliensbachian deeper-marine micro-oncoidal-crinoidal-ammonoid wacke- to packstone facies. Based on the presence of Fuciniceras lavinianum (Fucini), Lytoceras ovimontanum Geyer and Arieticeratinae gen. indet. from a hardground above the deeper-water micro-oncoidal limestones in the Mihajlovici section (northeastern Montenegro) a Late Pliensbachian to Early Toarcian condensation horizon is proven. The Middle Toarcian ammonoid-bearing horizon also yielded species not known from previous studies: Calliphylloceras capitanii (Catullo), Harpoceras subplanatum (Oppel) and Furloceras aff. chelussii (Parisch & Viale), also described in the present paper. These new data prove a stepwise deepening of the depositional area during the Early and the Middle Jurassic reflected in detail in four sedimentary members: 1) ?Late Hettangian to Sinemurian/? earliest Pliensbachian open-marine shallow subtital micro-oncoidal limestone; 2) ?Early to Late Pliensbachian open-marine condensed limestones with few micro-oncoids and more open-marine influence; 3) Toarcian openmarine condensed red limestones with hardgrounds; and 4} condensed red nodular Bositra Limestone. These four members are separated by hardrounds representing Stratigraphie gaps in deposition. The stepwise deepening during the Early-Middle Jurassic follows the general trend of deposition as known in the whole Western Tethys Realm above the Late Triassic Dachstein Carbonate Platform.

scholarly journals Digging into the ancestral stocks of Jurassic lineages: ostracods (Crustacea) from Carnian (Late Triassic) sponge mounds from the Maantang Formation (South China)

2019 ◽  
Vol 190 ◽  
pp. 9 ◽  
Author(s):  
Marie-Béatrice Forel ◽  
Ben Thuy ◽  
Max Wisshak
Keyword(s):  
South China ◽  
First Record ◽  
Late Triassic ◽  
Independent Evidence ◽  
Western Tethys ◽  
The Family ◽  
Northwestern Margin ◽  
Reef Mounds ◽  
Sponge Reef ◽  
First Time

Microbial-sponge reef mounds of the Carnian, Late Triassic, Maantang Formation crop out along the northwestern margin of the Sichuan Basin in South China. Samples from three mounds have been investigated and their ostracod assemblages are here described for the first time. Thirty-three species are present, distributed into 19 genera, including five newly described species: Carinobairdia cabralae n. sp., Hiatobairdia senegasi n. sp., Hiatobairdia zhengshuyingi n. sp., Hungarella gommerii n. sp, Pontocyprella goussardi n. sp. While most of the encountered genera are already known from the Carnian stage worldwide, the Maantang assemblages are precursors in providing the oldest occurrences of the family Schulerideidae, typical of the Middle and Late Jurassic of Europe, and of the genus Carinobairdia, which was until now restricted to the Norian-Rhaetian interval. These records demonstrate the underestimated importance of the easternmost Tethys in the early Mesozoic evolution of marine ostracods. Some important Jurassic European taxa might have originated on the eastern margin of the Tethys during the Carnian, migrated to the western Tethys later during the Late Triassic and diversified there up to the record known for the European Jurassic. Microbioerosion trace fossil analysis of associated brachiopod shells revealed Orthogonum giganteum as the sole identifiable ichnotaxon and represents the first record of this ichnospecies in Triassic strata. The complete absence of microborings produced by phototrophic trace makers points towards aphotic depths for the deposition of the Maantang Formation, providing independent evidence suggesting that typical shallow water ostracods (Carinobairdia, Schulerideidae) radiated in relatively deep settings.

scholarly journals Mercury deposition in Western Tethys during the Carnian Pluvial Episode (Late Triassic)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mina Mazaheri-Johari ◽  
Piero Gianolla ◽  
Tamsin A. Mather ◽  
Joost Frieling ◽  
Daoliang Chu ◽  
...  
Keyword(s):  
Hydrological Cycle ◽  
Large Igneous Province ◽  
Late Triassic ◽  
Mercury Deposition ◽  
Western Tethys ◽  
Sedimentary Records ◽  
Environmental Perturbations ◽  
Depositional Settings ◽  
Igneous Province ◽  
Multiple Pulses

AbstractThe Late Triassic Carnian Pluvial Episode (CPE) was a time of biological turnover and environmental perturbations. Within the CPE interval, C-isotope and sedimentary records indicate multiple pulses of depleted carbon into the atmosphere–ocean system linked to discrete enhancements of the hydrological cycle. Data suggest a similar cascade of events to other extinctions, including being potentially driven by emplacement of a large igneous province (LIP). The age of the Wrangellia LIP overlaps that of the CPE, but a direct link between volcanism and the pulsed CPE remains elusive. We present sedimentary Hg concentrations from Western Tethys successions to investigate volcanic activity through the previously established CPE global negative C-isotope excursions (NCIEs). Higher Hg concentrations and Hg/TOC are recorded just before and during NCIEs and siliciclastic inputs. The depositional settings suggest volcanic Hg inputs into the basins over the NCIEs rather than increases of Hg drawdown or riverine transport. Differences in Hg and Hg/TOC signals between the basins might be linked to coeval LIP style or the temporal resolution of the sedimentary successions. Overall, our new data provide support for a link between pulses of Wrangellia LIP volcanism, NCIEs, and humid phases that mark the CPE in the Western Tethys.

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