scholarly journals Atmospheric oxygen regulation at low Proterozoic levels by incomplete oxidative weathering of sedimentary organic carbon

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Stuart J. Daines ◽  
Benjamin J. W. Mills ◽  
Timothy M. Lenton
Keyword(s):  
Organic Carbon ◽  
Atmospheric Oxygen ◽  
Oxygen Regulation ◽  
Sedimentary Organic Carbon

Phanerozoic Oxygen

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Oxygen Consumption ◽  
Organic Carbon ◽  
Sea Level ◽  
Time Scale ◽  
Atmospheric Oxygen ◽  
Sea Level Change ◽  
Oxygen Production ◽  
Level Change ◽  
History Of ◽  
Geologic Processes

This chapter discusses the modeling of the history of atmospheric oxygen. The most recently deposited sediments will also be the most prone to weathering through processes like sea-level change or uplift of the land. Thus, through rapid recycling, high rates of oxygen production through the burial of organic-rich sediments will quickly lead to high rates of oxygen consumption through the exposure of these organic-rich sediments to weathering. From a modeling perspective, rapid recycling helps to dampen oxygen changes. This is important because the fluxes of oxygen through the atmosphere during organic carbon and pyrite burial, and by weathering, are huge compared to the relatively small amounts of oxygen in the atmosphere. Thus, all of the oxygen in the present atmosphere is cycled through geologic processes of oxygen liberation (organic carbon and pyrite burial) and consumption (weathering) on a time scale of about 2 to 3 million years.

Earth’s Middle Ages: What Came after the GOE

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Middle Ages ◽  
Atmospheric Oxygen ◽  
Iron Formation ◽  
Banded Iron Formation ◽  
Dissolved Iron ◽  
Great Oxidation Event ◽  
Low Levels ◽  
Substantial Rise

This chapter considers the aftermath of the great oxidation event (GOE). It suggests that there was a substantial rise in oxygen defining the GOE, which may, in turn have led to the Lomagundi isotope excursion, which was associated with high rates of organic matter burial and perhaps even higher concentrations of oxygen. This excursion was soon followed by a crash in oxygen to very low levels and a return to banded iron formation deposition. When the massive amounts of organic carbon buried during the excursion were brought into the weathering environment, they would have represented a huge oxygen sink, drawing down levels of atmospheric oxygen. There appeared to be a veritable seesaw in oxygen concentrations, apparently triggered initially by the GOE. The GOE did not produce enough oxygen to oxygenate the oceans. Dissolved iron was removed from the oceans not by reaction with oxygen but rather by reaction with sulfide. Thus, the deep oceans remained anoxic and became rich in sulfide, instead of becoming well oxygenated.

Variability of sedimentary organic carbon in patchy seagrass landscapes

2015 ◽  
Vol 100 (1) ◽  
pp. 476-482 ◽  
Author(s):  
Aurora M. Ricart ◽  
Paul H. York ◽  
Michael A. Rasheed ◽  
Marta Pérez ◽  
Javier Romero ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Sedimentary Organic Carbon

scholarly journals Metabolic evolution and the self-organization of ecosystems

2017 ◽  
Vol 114 (15) ◽  
pp. E3091-E3100 ◽  
Author(s):  
Rogier Braakman ◽  
Michael J. Follows ◽  
Sallie W. Chisholm
Keyword(s):  
Organic Carbon ◽  
Metabolic Rate ◽  
Light Adaptation ◽  
Atmospheric Oxygen ◽  
Heterotrophic Bacterium ◽  
The Self ◽  
Self Organization ◽  
Steady Increase ◽  
Mathematical Framework ◽  
Metabolic Evolution

Metabolism mediates the flow of matter and energy through the biosphere. We examined how metabolic evolution shapes ecosystems by reconstructing it in the globally abundant oceanic phytoplankterProchlorococcus. To understand what drove observed evolutionary patterns, we interpreted them in the context of its population dynamics, growth rate, and light adaptation, and the size and macromolecular and elemental composition of cells. This multilevel view suggests that, over the course of evolution, there was a steady increase inProchlorococcus’ metabolic rate and excretion of organic carbon. We derived a mathematical framework that suggests these adaptations lower the minimal subsistence nutrient concentration of cells, which results in a drawdown of nutrients in oceanic surface waters. This, in turn, increases total ecosystem biomass and promotes the coevolution of all cells in the ecosystem. Additional reconstructions suggest thatProchlorococcusand the dominant cooccurring heterotrophic bacterium SAR11 form a coevolved mutualism that maximizes their collective metabolic rate by recycling organic carbon through complementary excretion and uptake pathways. Moreover, the metabolic codependencies ofProchlorococcusand SAR11 are highly similar to those of chloroplasts and mitochondria within plant cells. These observations lead us to propose a general theory relating metabolic evolution to the self-amplification and self-organization of the biosphere. We discuss the implications of this framework for the evolution of Earth’s biogeochemical cycles and the rise of atmospheric oxygen.

Sedimentary Organic Carbon Budget Across the Slope to the Basin in the Southwestern Ulleung (Tsushima) Basin of the East (Japan) Sea

2019 ◽  
Vol 124 (9) ◽  
pp. 2804-2822
Author(s):  
Jae Seong Lee ◽  
Jeong Hee Han ◽  
Sung‐Uk An ◽  
Sung‐Han Kim ◽  
Dhongil Lim ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Budget ◽  
Japan Sea ◽  
Sedimentary Organic Carbon ◽  
Tsushima Basin

scholarly journals Mineral protection regulates the long-term global preservation of natural organic carbon

2021 ◽  
Author(s):  
Jordon Hemingway ◽  
Daniel Rothman ◽  
Katherine Grant ◽  
Sarah Rosengard ◽  
Timothy Eglinton ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Redox State ◽  
Global Climate ◽  
Atmospheric Oxygen ◽  
Atmospheric Composition ◽  
Earth Surface ◽  
Mountain Ranges ◽  
Surface Redox ◽  
Carbon Erosion

<p>The vast majority of organic carbon (OC) produced by life is respired back to carbon dioxide (CO<sub>2</sub>), but roughly 0.1% escapes and is preserved over geologic timescales. By sequestering reduced carbon from Earth’s surface, this “slow OC leak” contributes to CO<sub>2</sub> removal and promotes the accumulation of atmospheric oxygen and oxidized minerals. Countering this, OC contained within sedimentary rocks is oxidized during exhumation and erosion of mountain ranges. By respiring previously sequestered reduced carbon, erosion consumes atmospheric oxygen and produces CO<sub>2</sub>. The balance between these two processes—preservation and respiration—regulates atmospheric composition, Earth-surface redox state, and global climate. Despite this importance, the governing mechanisms remain poorly constrained. To provide new insight, we developed a method that investigates OC composition using bond-strength distributions coupled with radiocarbon ages. Here I highlight a suite of recent results using this approach, and I show that biospheric OC interacts with particles and becomes physiochemically protected during aging, thus promoting preservation. I will discuss how this mechanistic framework can help elucidate why OC preservation—and thus atmospheric composition, Earth-surface redox state, and climate—has varied throughout Earth history.</p>

Origin and effect factors of sedimentary organic carbon in a karst groundwater-fed reservoir, South China

2018 ◽  
Vol 25 (9) ◽  
pp. 8497-8511 ◽  
Author(s):  
Siyu Huang ◽  
Junbing Pu ◽  
Jianhua Cao ◽  
Jianhong Li ◽  
Tao Zhang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
South China ◽  
Karst Groundwater ◽  
Effect Factors ◽  
Sedimentary Organic Carbon

Enhanced paleo-wildfire occurrences caused by marine organic carbon burial during the Late Devonian Frasnian–Famennian mass extinction

2021 ◽  
Author(s):  
Man Lu ◽  
YueHan Lu ◽  
Takehitio Ikejiri ◽  
Richard Carroll
Keyword(s):  
Organic Carbon ◽  
Mass Extinction ◽  
Atmospheric Oxygen ◽  
Burial Rate ◽  
Carbon Burial ◽  
Chattanooga Shale ◽  
Chemical Index ◽  
Organic Carbon Burial ◽  
Polycyclic Aromatic ◽  
Extinction Events

<p>The Frasnian–Famennian (F–F) boundary is characterized by worldwide depositions of organic-rich strata, a series of marine anoxia events and one of the biggest five mass extinction events of the Phanerozoic. Due to the enhanced burial of organic matter, a coeval positive carbon isotope (δ<sup>13</sup>C) excursion occurred around the F–F boundary, raising questions about carbon cycle feedbacks during the mass extinction. In this study, we test the hypothesis that enhanced burial organic carbon during the F–F mass extinction led to the rise of paleo-wildfire occurrences. Here, we reconstructed paleo-wildfire changes across the F–F boundary via analyzing fossil charcoal (inertinites) and pyrogenic polycyclic aromatic hydrocarbons (PAHs) from an Upper Devonian Chattanooga Shale in the southern Appalachian Basin. Our data show low abundances of inertinites and pyrogenic PAHs before the F–F transition and an increasing trend during the F–F transition, followed by a sustained enhancement through the entire Famennian interval. The changes in paleo-wildfire proxies suggest a rise of wildfires starting from the F–F transition. Furthermore, we quantified the amount of organic carbon burial required to drive the observed δ<sup>13</sup>C excursion using a forward box model. The modeling results show an increased carbon burial rate after the onset of the F–F transition and peaking during its termination. The comparison of the carbon burial rate and wildfire proxies indicates that widespread organic carbon burial during the F–F transition might cause elevated atmospheric oxygen levels and hence increased occurrences of wildfires. In addition, chemical index alteration index and plant biomarkers suggest a drying climate initiated during the F–F transition, implying that the enhanced carbon burial probably result in the climate change and amplify the wildfire occurrences.</p>

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