scholarly journals Possible link between Earth’s rotation rate and oxygenation

2021 ◽  
Author(s):  
J. M. Klatt ◽  
A. Chennu ◽  
B. K. Arbic ◽  
B. A. Biddanda ◽  
G. J. Dick
Keyword(s):  
Metabolic Regulation ◽  
Atmospheric Oxygen ◽  
Dynamic Modelling ◽  
Low Oxygen ◽  
Geological Time ◽  
Net Productivity ◽  
Carbon Burial ◽  
Organic Carbon Burial ◽  
Solute Fluxes ◽  
Benthic Ecosystems

AbstractThe biotic and abiotic controls on major shifts in atmospheric oxygen and the persistence of low-oxygen periods over a majority of Earth’s history remain under debate. Explanations of Earth’s stepwise pattern of oxygenation have mostly neglected the effect of changing diel illumination dynamics linked to daylength, which has increased through geological time due to Earth’s rotational deceleration caused by tidal friction. Here we used microsensor measurements and dynamic modelling of interfacial solute fluxes in cyanobacterial mats to investigate the effect of changing daylength on Precambrian benthic ecosystems. Simulated increases in daylength across Earth’s historical range boosted the diel benthic oxygen export, even when the gross photosynthetic production remained constant. This fundamental relationship between net productivity and daylength emerges from the interaction of diffusive mass transfer and diel illumination dynamics, and is amplified by metabolic regulation and microbial behaviour. We found that the resultant daylength-driven surplus organic carbon burial could have shaped the increase in atmospheric oxygen that occurred during the Great and Neoproterozoic Oxidation Events. Our suggested mechanism, which links the coinciding increases in daylength and atmospheric oxygen via enhanced net productivity, reveals a possible contribution of planetary mechanics to the evolution of Earth’s biology and geochemistry.

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>

scholarly journals Microbial bioavailability regulates organic matter preservation in marine sediments

2013 ◽  
Vol 10 (2) ◽  
pp. 1131-1141 ◽  
Author(s):  
K. A. Koho ◽  
K. G. J. Nierop ◽  
L. Moodley ◽  
J. J. Middelburg ◽  
L. Pozzato ◽  
...  
Keyword(s):  
Organic Matter ◽  
Marine Sediments ◽  
Source Rocks ◽  
Low Oxygen ◽  
Carbon Burial ◽  
Organic Carbon Burial ◽  
Oxygen Conditions ◽  
The Indian Ocean ◽  
Biochemical Quality ◽  
Oil Source

Abstract. Burial of organic matter (OM) plays an important role in marine sediments, linking the short-term, biological carbon cycle with the long-term, geological subsurface cycle. It is well established that low-oxygen conditions promote organic carbon burial in marine sediments. However, the mechanism remains enigmatic. Here we report biochemical quality, microbial degradability, OM preservation and accumulation along an oxygen gradient in the Indian Ocean. Our results show that more OM, with biochemically higher quality, accumulates under low oxygen conditions. Nevertheless, microbial degradability does not correlate with the biochemical quality of OM. This decoupling of OM biochemical quality and microbial degradability, or bioavailability, violates the ruling paradigm that higher quality implies higher microbial processing. The inhibition of bacterial OM remineralisation may play an important role in the burial of organic matter in marine sediments and formation of oil source rocks.

scholarly journals Earliest land plants created modern levels of atmospheric oxygen

2016 ◽  
Vol 113 (35) ◽  
pp. 9704-9709 ◽  
Author(s):  
Timothy M. Lenton ◽  
Tais W. Dahl ◽  
Stuart J. Daines ◽  
Benjamin J. W. Mills ◽  
Kazumi Ozaki ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Land Surface ◽  
Atmospheric Oxygen ◽  
Geochemical Data ◽  
Regulatory Regime ◽  
Carbon Burial ◽  
C:P Ratio ◽  
Marine Biomass ◽  
Organic Carbon Burial

The progressive oxygenation of the Earth’s atmosphere was pivotal to the evolution of life, but the puzzle of when and how atmospheric oxygen (O2) first approached modern levels (∼21%) remains unresolved. Redox proxy data indicate the deep oceans were oxygenated during 435–392 Ma, and the appearance of fossil charcoal indicates O2 >15–17% by 420–400 Ma. However, existing models have failed to predict oxygenation at this time. Here we show that the earliest plants, which colonized the land surface from ∼470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial—the net long-term source of O2. We use a trait-based ecophysiological model to predict that cryptogamic vegetation cover could have achieved ∼30% of today’s global terrestrial net primary productivity by ∼445 Ma. Data from modern bryophytes suggests this plentiful early plant material had a much higher molar C:P ratio (∼2,000) than marine biomass (∼100), such that a given weathering flux of phosphorus could support more organic carbon burial. Furthermore, recent experiments suggest that early plants selectively increased the flux of phosphorus (relative to alkalinity) weathered from rocks. Combining these effects in a model of long-term biogeochemical cycling, we reproduce a sustained +2‰ increase in the carbonate carbon isotope (δ13C) record by ∼445 Ma, and predict a corresponding rise in O2 to present levels by 420–400 Ma, consistent with geochemical data. This oxygen rise represents a permanent shift in regulatory regime to one where fire-mediated negative feedbacks stabilize high O2 levels.

scholarly journals Microbial bioavailability regulates organic matter preservation in marine sediments

2012 ◽  
Vol 9 (9) ◽  
pp. 13187-13210
Author(s):  
K. A. Koho ◽  
K. G. J. Nierop ◽  
L. Moodley ◽  
J. J. Middelburg ◽  
L. Pozzato ◽  
...  
Keyword(s):  
Organic Matter ◽  
Marine Sediments ◽  
Source Rocks ◽  
Low Oxygen ◽  
Carbon Burial ◽  
Organic Carbon Burial ◽  
Oxygen Conditions ◽  
The Indian Ocean ◽  
Biochemical Quality ◽  
Oil Source

Abstract. Burial of organic matter (OM) plays an important role in marine sediments, linking the short-term, biological carbon cycle with the long-term, geological subsurface cycle. It is well established that low-oxygen conditions promote organic carbon burial in marine sediments. However, the mechanism remains enigmatic. Here we report biochemical quality, microbial degradability, OM preservation and accumulation along an oxygen gradient in the Indian Ocean. Our results show that more OM, and of biochemically higher quality, accumulates under low oxygen conditions. Nevertheless, microbial degradability does not correlate with the biochemical quality of OM. This decoupling of OM biochemical quality and microbial degradability, or bioavailability, violates the ruling paradigm that higher quality implies higher microbial processing. The inhibition of bacterial OM remineralisation may play an important role in the burial of organic matter in marine sediments and formation of oil source rocks.

What Controls Atmospheric Oxygen Concentrations?

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Black Sea ◽  
Atmospheric Oxygen ◽  
Fundamental Question ◽  
The Black Sea ◽  
Microbial Process ◽  
The Past ◽  
Carbon Burial ◽  
Organic Carbon Burial

This chapter deals with the fundamental question of why there is oxygen in the atmosphere at all. It seeks to identify the main processes controlling the oxygen concentration. Plants and cyanobacteria produce the oxygen, but it accumulates only because some of the original photosynthetically produced organic matter is buried and preserved in sediments. Another oxygen source is an anaerobic microbial process called sulfate reduction that respires organic matter using sulfate and produces sulfide. This process is quite common in nature but are most prominent in relatively isolated basins like the Black Sea, and in most marine sediments at depths where oxygen has been consumed by respiration. If there is iron around, the sulfide reacts with the iron, forming a mineral called pyrite. While organic carbon burial has been the main oxygen source to the atmosphere over the past several hundred million years, for some intervals further back in time, pyrite burial may well have dominated as an oxygen source.

Herbivory and its effect on Phanerozoic oxygen concentrations

Geology ◽  
2020 ◽  
Vol 48 (4) ◽  
pp. 410-414
Author(s):  
T.A. Laakso ◽  
J.V. Strauss ◽  
K.J. Peterson
Keyword(s):  
Organic Compounds ◽  
Atmospheric Oxygen ◽  
Deep Ocean ◽  
Land Plant ◽  
Plant Colonization ◽  
Terrestrial Plants ◽  
Oxygen Levels ◽  
Carbon Burial ◽  
Organic Carbon Burial

Abstract The appearance of terrestrial land plants is thought to have accompanied an increase in atmospheric oxygen levels, producing the highest O2 concentrations estimated from the geological record, and marking the transition to a permanently oxygenated deep ocean. This Paleozoic oxygenation event, which likely peaked in the Carboniferous Period, was at least partially mediated by the development of recalcitrant, carbon-rich organic compounds in terrestrial plants. A number of studies have argued that shifts in coal formation and paleogeography led to declining preservation of these compounds on land, depressing oxygen levels in the terminal Paleozoic and early Mesozoic. In contrast, we propose that the evolution and diversification of terrestrial herbivores may have limited transport and long-term burial of terrestrial organic compounds in marine sediments, resulting in less organic carbon burial and attendant declines in atmospheric oxygen. This mechanism suggests that interactions among a triad of biological processes—marine photosynthesis, land plant colonization, and the advent of herbivory—may have dictated the long-term redox state of Earth’s surface environments over the Phanerozoic Eon.

scholarly journals The rise of angiosperms strengthened fire feedbacks and improved the regulation of atmospheric oxygen

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Claire M. Belcher ◽  
Benjamin J. W. Mills ◽  
Rayanne Vitali ◽  
Sarah J. Baker ◽  
Timothy M. Lenton ◽  
...  
Keyword(s):  
Atmospheric Oxygen ◽  
Feedback Mechanism ◽  
Biogeochemical Model ◽  
Fossil Carbon ◽  
Biogeochemical Models ◽  
Carbon Burial ◽  
Plant Groups ◽  
Organic Carbon Burial ◽  
Closed Canopy ◽  
Fire Feedbacks

AbstractThe source of oxygen to Earth’s atmosphere is organic carbon burial, whilst the main sink is oxidative weathering of fossil carbon. However, this sink is to insensitive to counteract oxygen rising above its current level of about 21%. Biogeochemical models suggest that wildfires provide an additional regulatory feedback mechanism. However, none have considered how the evolution of different plant groups through time have interacted with this feedback. The Cretaceous Period saw not only super-ambient levels of atmospheric oxygen but also the evolution of the angiosperms, that then rose to dominate Earth’s ecosystems. Here we show, using the COPSE biogeochemical model, that angiosperm-driven alteration of fire feedbacks likely lowered atmospheric oxygen levels from ~30% to 25% by the end of the Cretaceous. This likely set the stage for the emergence of closed-canopy angiosperm tropical rainforests that we suggest would not have been possible without angiosperm enhancement of fire feedbacks.

scholarly journals Organic carbon burial efficiency in a subtropical hydroelectric reservoir

2016 ◽  
Vol 13 (11) ◽  
pp. 3331-3342 ◽  
Author(s):  
Raquel Mendonça ◽  
Sarian Kosten ◽  
Sebastian Sobek ◽  
Simone Jaqueline Cardoso ◽  
Marcos Paulo Figueiredo-Barros ◽  
...  
Keyword(s):  
Organic Carbon ◽  
High Efficiency ◽  
Accumulation Rate ◽  
Sediment Accumulation ◽  
Low Oxygen ◽  
Spatially Resolved ◽  
Natural Lakes ◽  
Carbon Burial ◽  
Organic Carbon Burial ◽  
Burial Efficiency

Abstract. Hydroelectric reservoirs bury significant amounts of organic carbon (OC) in their sediments. Many reservoirs are characterized by high sedimentation rates, low oxygen concentrations in bottom water and a high share of terrestrially derived OC, and all of these factors have been linked to a high efficiency of OC burial. However, investigations of OC burial efficiency (OCBE, i.e., the ratio between buried and deposited OC) in reservoirs are limited to a few studies, none of which include spatially resolved analyses. In this study we determined the spatial variation in OCBE in a large subtropical reservoir and related it to sediment characteristics. Our results show that the sediment accumulation rate explains up to 92 % of the spatial variability in OCBE, outweighing the effect of other variables, such as OC source and oxygen exposure time. OCBE at the pelagic sites varied from 48 to 86 % (mean 67 %) and decreased towards the dam. At the margins, OCBE was lower (9–17 %) due to the low sediment accumulation in shallow areas. Our data show that the variability in OCBE both along the rivers–dam and the margin–pelagic axes must be considered in whole-reservoir assessments. Combining these results with a spatially resolved assessment of sediment accumulation and OC burial in the studied reservoir, we estimated a spatially resolved mean OC burial efficiency of 57 %. Being the first assessment of OCBE with such a high spatial resolution in a reservoir, these results suggest that reservoirs may bury OC more efficiently than natural lakes.

scholarly journals Phosphorus burial in ferruginous SiO2-rich Mesoproterozoic sediments

Geology ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 92-96 ◽  
Author(s):  
Brooke R. Johnson ◽  
Rosalie Tostevin ◽  
Philip Gopon ◽  
Jon Wells ◽  
Stuart A. Robinson ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Phosphorus Removal ◽  
Net Primary Production ◽  
Atmospheric Oxygen ◽  
Carbon Burial ◽  
Phosphate Availability ◽  
Organic Carbon Burial ◽  
Chemical Factors ◽  
Inorganic Phosphorous ◽  
Physical And Chemical

Abstract Persistently low atmospheric oxygen requires that net organic carbon burial was muted through much of Earth’s middle age. In order to achieve global mass balance with respect to O2, recent models have suggested that redox-dependent mechanisms, such as Fe(II)-phosphate precipitation, limited phosphate availability in dominantly anoxic and ferruginous oceans, in turn limiting net primary production, and therefore organic carbon burial. Nevertheless, observational constraints on phosphorus cycling in ferruginous Proterozoic systems are rare, leaving these models largely untested. Here, we present high-resolution petrographic and mineralogical data showing that the 1.3 Ga Sherwin Ironstone (Roper Group, Australia) was dominated by syndepositional precipitation of the Fe(II)-silicate minerals greenalite and berthierine, interlaminated with abundant authigenic calcium fluorapatite (CFA). Set in a quantitative geochemical framework, these data reveal that elevated marine SiO2(aq) concentrations facilitated extensive Fe(II)-silicate production, leaving CFA, rather than Fe(II)-phosphate, as the principal inorganic phosphorous sink in shallow-water Roper Group sediments. More broadly, the physical and chemical factors that triggered Fe(II)-silicate and CFA burial in the Roper Seaway highlight semi-restricted basins as important loci of phosphorus removal from the mid-Proterozoic ocean.

scholarly journals Past climate variations recorded in needle-like aragonites correlate with organic carbon burial efficiency as revealed by lake sediments in Croatia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ivan Razum ◽  
Petra Bajo ◽  
Dea Brunović ◽  
Nikolina Ilijanić ◽  
Ozren Hasan ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Stable Carbon Isotope ◽  
Climate Variations ◽  
Before Present ◽  
Stable Carbon ◽  
Climate Trends ◽  
Geochemical Proxies ◽  
Carbon Burial ◽  
Organic Carbon Burial ◽  
Burial Efficiency

AbstractThe drivers of organic carbon (OC) burial efficiency are still poorly understood despite their key role in reliable projections of future climate trends. Here, we provide insights on this issue by presenting a paleoclimate time series of sediments, including the OC contents, from Lake Veliko jezero, Croatia. The Sr/Ca ratios of the bulk sediment are mainly derived from the strontium (Sr) and calcium (Ca) concentrations of needle-like aragonite in Core M1-A and used as paleotemperature and paleohydrology indicators. Four major and six minor cold and dry events were detected in the interval from 8.3 to 2.6 calibrated kilo anno before present (cal ka BP). The combined assessment of Sr/Ca ratios, OC content, carbon/nitrogen (C/N) ratios, stable carbon isotope (δ13C) ratios, and modeled geochemical proxies for paleoredox conditions and aeolian input revealed that cold and dry climate states promoted anoxic conditions in the lake, thereby enhancing organic matter preservation and increasing the OC burial efficiency. Our study shows that the projected future increase in temperature might play an important role in the OC burial efficiency of meromictic lakes.

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