scholarly journals Carbonate platform production during the Cretaceous

2020 ◽  
Vol 132 (11-12) ◽  
pp. 2606-2610 ◽  
Author(s):  
Alexandre Pohl ◽  
Yannick Donnadieu ◽  
Yves Godderis ◽  
Cyprien Lanteaume ◽  
Alex Hairabian ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbonate Platform ◽  
Carbonate Platforms ◽  
Carbon Cycle Model ◽  
Carbonate Production ◽  
Volcanic Degassing ◽  
First Order ◽  
Carbonate Deposition ◽  
Underlying Mechanisms ◽  
Unimodal Pattern

Abstract Platform carbonates are among the most voluminous of Cretaceous deposits. The production of carbonate platforms fluctuated through time. Yet, the reasons for these fluctuations are not well understood, and the underlying mechanisms remain largely unconstrained. Here we document the long-term trend in Cretaceous carbonate platform preservation based on a new data compilation and use a climate-carbon cycle model to explore the drivers of carbonate platform production during the Cretaceous. We show that neritic carbonate preservation rates followed a unimodal pattern during the Cretaceous and reached maximum values during the mid-Cretaceous (Albian, 110 Ma). Coupled climate-carbon cycle modeling reveals that this maximum in carbonate deposition results from a unique combination of high volcanic degassing rates and widespread shallow-marine environments that served as a substrate for neritic carbonate deposition. Our experiments demonstrate that the unimodal pattern in neritic carbonate accumulation agrees well with most of the volcanic degassing scenarios for the Cretaceous. Our results suggest that the first-order temporal evolution of neritic carbonate production during the Cretaceous reflects changes in continental configuration and volcanic degassing. Geodynamics, by modulating accommodation space, and turnovers in the dominant biota probably played a role as well, but it is not necessary to account for the latter processes to explain the first-order trend in Cretaceous neritic carbonate accumulation in our simulations.

scholarly journals The siliciclastics/carbonates shift in the Jurassic of the Western Caucasus (central northern Neo-Tethys): reconsidering research over the last 50 years

Geologos ◽  
2019 ◽  
Vol 25 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Dmitry A. Ruban
Keyword(s):  
Sea Water ◽  
Current Knowledge ◽  
Carbonate Platform ◽  
Temporal Distribution ◽  
Tectonic Activity ◽  
Carbonate Platforms ◽  
Western Caucasus ◽  
Carbonate Production ◽  
The Western Caucasus ◽  
Spatio Temporal

Abstract A chain of carbonate platforms evolved in the northern Neo-Tethys during the Late Jurassic, but current knowledge remains incomplete as long as data from several larger regions, such as the Western Caucasus, are not included. In order to fill this gap, it is here suggested to reconsider the information accumulated chiefly during Soviet times. Although these data are too general, they still matter with regard to some regional characteristics and tentative interpretations. Available data on the spatio-temporal distribution of Bajocian-Callovian sedimentary rocks are summarised in a novel way which permits documentation of depositional trends at six representative localities in the Western Caucasus. The extent of the carbonate platform increased at two localities since the Late Callovian and at a third since the Middle Oxfordian. Three additional sites were characterised either by non-deposition or deep-marine sedimentation. The onset of carbonate platform development marked a remarkable shift from chiefly siliciclastic to carbonate deposition, although this event was not sudden everywhere. The Bathonian pulse of tectonic activity, coupled with the eustatic sea level rise, allowed shelves to expand during the Callovian-Oxfordian, with a reduction in siliciclastic input from islands and sea-water that became well oxygenated and warmer. These conditions were conducive to biogenic carbonate production, allowing the carbonate platform to expand subsequently.

An Integrated Approach To Forward Modeling Carbonate Platform Development

1994 ◽  
Author(s):  
Helmut Mayer
Keyword(s):  
Carbonate Platform ◽  
Sediment Accumulation ◽  
Integrated Approach ◽  
Forward Modeling ◽  
Carbonate Platforms ◽  
Carbonate Production ◽  
Geometric Evolution ◽  
Sediment Redistribution ◽  
Key Variables ◽  
The One

The forward model presented here is designed to simulate stratigraphic and geometric development of carbonate platforms. Starting from an initial basement geometry, the effects of a number of key variables on water depth are combined for each time increment. This procedure is repeated in an iterative fashion for subsequent time steps. The variables considered include subsidence, carbonate production, sediment redistribution, compaction, isostatic compensation, and eustatic sea-level change. Time- or depth-dependent functions are developed for these variables. Free parameters in these functions allow fitting to realistic magnitudes. A sample simulation demonstrates the characteristics of the model and indicates its usefulness in case studies and predictions. In recent years a number of studies on the modeling of sediment accumulation in various basin settings has been published. Most of them are concerned with clastic basin fill or do not discriminate lithologies (e.g., Turcotte and Kenyon, 1984; Kenyon and Turcotte, 1985; Tetzlaff, 1986; Bitzer and Harbaugh, 1987; Flemings and Jordan, 1987, 1989; Tetzlaff and Harbaugh, 1989; Jervey, 1989), while only few focus on mixed clastic/carbonate systems (e.g., Aigner et al., 1989; Lawrence et al., 1990) or carbonate platforms (e.g., Lerche et al., 1987; Bice, 1988; Demicco and Spencer, 1989; Scaturo et al., 1989). Sediment accumulation and distribution on a carbonate platform and the adjacent slope represent a highly complex system of numerous interdependent factors which in concert determine the development of the stratigraphy and geometry of the platform. The goal of this study is to develop a model that yields a "best compromise" between two principal targets: representation of all important variables in geologically reasonable functional relationships on the one hand, and simplicity on the other. Forward modeling of sedimentary systems serves to simulate the stratigraphic and geometric evolution of the system, dependent on variations in the input parameters. The purpose of this approach is to establish the critical variables and parameters which dominate the system and to produce a geologically reasonable generic stratigraphic pattern. The next step then would be to use the model to reproduce known patterns of actual modern or ancient sedimentary systems (inverse modeling).

scholarly journals Exceptionally preserved calcified sponge assemblagesin Upper Jurassic carbonates of the eastern Getic Carbonate Platform (Southern Carpathians, Romania)

2021 ◽  
Author(s):  
George PLEŞ ◽  
Felix SCHLAGINTWEIT ◽  
Iuliana LAZĂR ◽  
Ioan I. BUCUR ◽  
Emanoil SĂSĂRAN ◽  
...  
Keyword(s):  
Carbonate Platform ◽  
Distribution Patterns ◽  
Upper Jurassic ◽  
Nutrient Competition ◽  
Carbonate Platforms ◽  
Diagnostic Features ◽  
Carbonate Production ◽  
Reef Area ◽  
Morphological Adaptations ◽  
Calcified Sponges

A rich poriferan assemblage was identified within the easternmost part of the Getic Carbonate Platform of Romania (Grădiștei Gorges). The excellent preservation state of most poriferans here led to the discovery of a new species (Neuropora gigantea Pleș & Schlagintweit, n. sp.) and to the identification of previously unknown diagnostic features in some species (Sarsteinia babai Schlagintweit & Gawlick, 2006 emend., Neuropora lusitanica Termier, 1985, Sphaeractinia steinmanni Canavari, 1893). Calciagglutispongia yabei Reitner, 1992, Sarsteinia babai and Sphaeractinia steinmanni are reported for the first time from the Upper Jurassic carbonates of the Getic Carbonate Platform. The sedimentary input fluctuations and the nutrient competition had an important role in understanding the morphological adaptations of the analysed species. The existing palaeoecological and palaeoenvironmental conditions generated different distribution patterns towards the reef profile and also preferential adaptations to a specific Tethyan domain. As opposed to the poriferan assemblages from the northern Tethyan shelves, these organisms formed sponge-coral-microencruster boundstones at the margins and fore-reefal zones of isolated carbonate platforms within the intra-Tethyan realm. The importance of calcified sponges in reef-zonation is highlighted by the establishment of a general zonation model. Three zones can be distinguished: 1) Cladocoropsis-Milleporidium zone (back-reef area); 2) Bauneia-Chaetetopsis-Parastromatopora zone (central reef area); and 3) Sphaeractinia/Ellipsactinia-Neuropora zone for the fore-reef area. In the absence of a true reef framework these calcified sponges developed typical morphologies, environmental adaptations and partnerships with other biotic groups which strongly influenced the carbonate production throughout the intra-Tethyan domain.

Sensitivity of a coupled climate-carbon cycle model to large volcanic eruptions during the last millennium

Tellus B ◽  
2010 ◽  
Vol 62 (5) ◽  
Author(s):  
Victor Brovkin ◽  
Stephan J. Lorenz ◽  
Johann Jungclaus ◽  
Thomas Raddatz ◽  
Claudia Timmreck ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Volcanic Eruptions ◽  
Last Millennium ◽  
Cycle Model ◽  
Carbon Cycle Model ◽  
Large Volcanic Eruptions

Designing and Implementing an Online Carbon Cycle Model Service Platform Based on OGC Web Processing Service

2012 ◽  
Vol 14 (3) ◽  
pp. 320-326
Author(s):  
Nan WU ◽  
Honglin HE ◽  
Li ZHANG ◽  
Xiaoli REN ◽  
Yuanchun ZHOU ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Cycle Model ◽  
Service Platform ◽  
Carbon Cycle Model ◽  
Processing Service

scholarly journals A record of Neogene seawater <i>δ</i><sup>11</sup>B reconstructed from paired <i>δ</i><sup>11</sup>B analyses on benthic and planktic foraminifera

2017 ◽  
Vol 13 (2) ◽  
pp. 149-170 ◽  
Author(s):  
Rosanna Greenop ◽  
Mathis P. Hain ◽  
Sindia M. Sosdian ◽  
Kevin I. C. Oliver ◽  
Philip Goodwin ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Middle Miocene ◽  
Isotope Composition ◽  
Boron Isotope ◽  
Mineral Formation ◽  
Secondary Mineral ◽  
Cycle Model ◽  
Planktic Foraminifera ◽  
Carbon Cycle Model ◽  
Secondary Mineral Formation

Abstract. The boron isotope composition (δ11B) of foraminiferal calcite reflects the pH and the boron isotope composition of the seawater the foraminifer grew in. For pH reconstructions, the δ11B of seawater must therefore be known, but information on this parameter is limited. Here we reconstruct Neogene seawater δ11B based on the δ11B difference between paired measurements of planktic and benthic foraminifera and an estimate of the coeval water column pH gradient from their δ13C values. Carbon cycle model simulations underscore that the ΔpH–Δδ13C relationship is relatively insensitive to ocean and carbon cycle changes, validating our approach. Our reconstructions suggest that δ11Bsw was  ∼  37.5 ‰ during the early and middle Miocene (roughly 23–12 Ma) and rapidly increased during the late Miocene (between 12 and 5 Ma) towards the modern value of 39.61 ‰. Strikingly, this pattern is similar to the evolution of the seawater isotope composition of Mg, Li and Ca, suggesting a common forcing mechanism. Based on the observed direction of change, we hypothesize that an increase in secondary mineral formation during continental weathering affected the isotope composition of riverine input to the ocean since 14 Ma.

About this title - Seismic Characterization of Carbonate Platforms and Reservoirs

10.1144/sp509 ◽  
2021 ◽  
Vol 509 (1) ◽  
pp. NP-NP
Author(s):  
J. Hendry ◽  
P. Burgess ◽  
D. Hunt ◽  
X. Janson ◽  
V. Zampetti
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Carbonate Platform ◽  
Carbonate Platforms ◽  
Oil And Gas Exploration ◽  
Seismic Modelling ◽  
Flow Units ◽  
Development Data ◽  
Seismic Characterization

Modern seismic data have become an essential toolkit for studying carbonate platforms and reservoirs in impressive detail. Whilst driven primarily by oil and gas exploration and development, data sharing and collaboration are delivering fundamental geological knowledge on carbonate systems, revealing platform geomorphologies and how their evolution on millennial time scales, as well as kilometric length scales, was forced by long-term eustatic, oceanographic or tectonic factors. Quantitative interrogation of modern seismic attributes in carbonate reservoirs permits flow units and barriers arising from depositional and diagenetic processes to be imaged and extrapolated between wells.This volume reviews the variety of carbonate platform and reservoir characteristics that can be interpreted from modern seismic data, illustrating the benefits of creative interaction between geophysical and carbonate geological experts at all stages of a seismic campaign. Papers cover carbonate exploration, including the uniquely challenging South Atlantic pre-salt reservoirs, seismic modelling of carbonates, and seismic indicators of fluid flow and diagenesis.

scholarly journals Analytically tractable climate–carbon cycle feedbacks under 21st century anthropogenic forcing

2018 ◽  
Vol 9 (2) ◽  
pp. 507-523 ◽  
Author(s):  
Steven J. Lade ◽  
Jonathan F. Donges ◽  
Ingo Fetzer ◽  
John M. Anderies ◽  
Christian Beer ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Global Climate ◽  
Future Climate Change ◽  
Earth System ◽  
Co2 Solubility ◽  
Carbon Cycle Model ◽  
Ocean Climate ◽  
System Models ◽  
Analytical Expressions ◽  
Earth System Models

Abstract. Changes to climate–carbon cycle feedbacks may significantly affect the Earth system's response to greenhouse gas emissions. These feedbacks are usually analysed from numerical output of complex and arguably opaque Earth system models. Here, we construct a stylised global climate–carbon cycle model, test its output against comprehensive Earth system models, and investigate the strengths of its climate–carbon cycle feedbacks analytically. The analytical expressions we obtain aid understanding of carbon cycle feedbacks and the operation of the carbon cycle. Specific results include that different feedback formalisms measure fundamentally the same climate–carbon cycle processes; temperature dependence of the solubility pump, biological pump, and CO2 solubility all contribute approximately equally to the ocean climate–carbon feedback; and concentration–carbon feedbacks may be more sensitive to future climate change than climate–carbon feedbacks. Simple models such as that developed here also provide workbenches for simple but mechanistically based explorations of Earth system processes, such as interactions and feedbacks between the planetary boundaries, that are currently too uncertain to be included in comprehensive Earth system models.

scholarly journals Recent changes in the global and regional carbon cycle: analysis of first-order diagnostics

2015 ◽  
Vol 12 (3) ◽  
pp. 835-844 ◽  
Author(s):  
P. J. Rayner ◽  
A. Stavert ◽  
M. Scholze ◽  
A. Ahlström ◽  
C. E. Allison ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Linear Response ◽  
Anthropogenic Emissions ◽  
Seasonal Patterns ◽  
Atmospheric Concentration ◽  
First Order ◽  
Northern Summer ◽  
Data Points ◽  
Natural Carbon ◽  
The Tropics

Abstract. We analyse global and regional changes in CO2 fluxes using two simple models, an airborne fraction of anthropogenic emissions and a linear relationship with CO2 concentrations. We show that both models are able to fit the non-anthropogenic (hereafter natural) flux over the length of the atmospheric concentration record. Analysis of the linear model (including its uncertainties) suggests no significant decrease in the response of the natural carbon cycle. Recent data points rather to an increase. We apply the same linear diagnostic to fluxes from atmospheric inversions. Flux responses show clear regional and seasonal patterns driven by terrestrial uptake in the northern summer. Ocean fluxes show little or no linear response. Terrestrial models show clear responses, agreeing globally with the inversion responses, however the spatial structure is quite different, with dominant responses in the tropics rather than the northern extratropics.

scholarly journals Triassic metasediments in the internal Dinarides (Kopaonik area, southern Serbia): stratigraphy, paleogeographic and tectonic significance

2010 ◽  
Vol 61 (2) ◽  
pp. 89-109 ◽  
Author(s):  
Senecio Schefer ◽  
Daniel Egli ◽  
Sigrid Missoni ◽  
Daniel Bernoulli ◽  
Bernhard Fügenschuh ◽  
...  
Keyword(s):  
Shallow Water ◽  
Lower Triassic ◽  
Turbidity Currents ◽  
Distal Margin ◽  
Carbonate Platforms ◽  
Carbonate Production ◽  
Tectonic Significance ◽  
Internal Dinarides ◽  
Water Carbonate ◽  
Shallow Water Carbonate

Triassic metasediments in the internal Dinarides (Kopaonik area, southern Serbia): stratigraphy, paleogeographic and tectonic significanceStrongly deformed and metamorphosed sediments in the Studenica Valley and Kopaonik area in southern Serbia expose the easternmost occurrences of Triassic sediments in the Dinarides. In these areas, Upper Paleozoic terrigenous sediments are overlain by Lower Triassic siliciclastics and limestones and by Anisian shallow-water carbonates. A pronounced facies change to hemipelagic and distal turbiditic, cherty metalimestones (Kopaonik Formation) testifies a Late Anisian drowning of the former shallow-water carbonate shelf. Sedimentation of the Kopaonik Formation was contemporaneous with shallow-water carbonate production on nearby carbonate platforms that were the source areas of diluted turbidity currents reaching the depositional area of this formation. The Kopaonik Formation was dated by conodont faunas as Late Anisian to Norian and possibly extends into the Early Jurassic. It is therefore considered an equivalent of the grey Hallstatt facies of the Eastern Alps, the Western Carpathians, and the Albanides-Hellenides. The coeval carbonate platforms were generally situated in more proximal areas of the Adriatic margin, whereas the distal margin was dominated by hemipelagic/pelagic and distal turbiditic sedimentation, facing the evolving Neotethys Ocean to the east. A similar arrangement of Triassic facies belts can be recognized all along the evolving Meliata-Maliac-Vardar branch of Neotethys, which is in line with a ‘one-ocean-hypothesis’ for the Dinarides: all the ophiolites presently located southwest of the Drina-Ivanjica and Kopaonik thrust sheets are derived from an area to the east, and the Drina-Ivanjica and Kopaonik units emerge in tectonic windows from below this ophiolite nappe. On the base of the Triassic facies distribution we see neither argument for an independent Dinaridic Ocean nor evidence for isolated terranes or blocks.

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