Phosphorus burial in ferruginous SiO2-rich Mesoproterozoic sediments

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.

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

10.5194/egusphere-egu21-10132 ◽

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

The Frasnian&#8211;Famennian (F&#8211;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 (&#948;13C) excursion occurred around the F&#8211;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&#8211;F mass extinction led to the rise of paleo-wildfire occurrences. Here, we reconstructed paleo-wildfire changes across the F&#8211;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&#8211;F transition and an increasing trend during the F&#8211;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&#8211;F transition. Furthermore, we quantified the amount of organic carbon burial required to drive the observed &#948;13C excursion using a forward box model. The modeling results show an increased carbon burial rate after the onset of the F&#8211;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&#8211;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&#8211;F transition, implying that the enhanced carbon burial probably result in the climate change and amplify the wildfire occurrences.

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Earliest land plants created modern levels of atmospheric oxygen

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1604787113 ◽

2016 ◽

Vol 113 (35) ◽

pp. 9704-9709 ◽

Cited By ~ 99

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.

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What Controls Atmospheric Oxygen Concentrations?

10.23943/princeton/9780691145020.003.0005 ◽

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.

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

Scientific Reports ◽

10.1038/s41598-021-87166-2 ◽

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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Organic carbon burial rates across the Arctic Ocean from the 1994 Arctic Ocean Section expedition

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/s0967-0645(97)00065-9 ◽

1997 ◽

Vol 44 (8) ◽

pp. 1705-1723 ◽

Cited By ~ 11

Author(s):

Ray E. Cranston

Keyword(s):

Organic Carbon ◽

Arctic Ocean ◽

The Arctic ◽

Carbon Burial ◽

Organic Carbon Burial ◽

The Arctic Ocean ◽

Burial Rates

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Climate influence on organic carbon burial efficiency as revealed from a multi-proxy lake sediment record in Croatia

10.1002/essoar.10504565.1 ◽

2020 ◽

Author(s):

Ivan Razum ◽

Petra Bajo ◽

Dea Brunović ◽

Nikolina Ilijanić ◽

Ozren Hasan ◽

...

Keyword(s):

Organic Carbon ◽

Lake Sediment ◽

Sediment Record ◽

Carbon Burial ◽

Organic Carbon Burial ◽

Burial Efficiency

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Long-term Aptian marine osmium isotopic record of Ontong Java Nui activity

Geology ◽

10.1130/g48863.1 ◽

2021 ◽

Author(s):

Hironao Matsumoto ◽

Rodolfo Coccioni ◽

Fabrizio Frontalini ◽

Kotaro Shirai ◽

Luigi Jovane ◽

...

Keyword(s):

Organic Carbon ◽

Volcanic Eruptions ◽

Hydrothermal Activity ◽

Published Data ◽

Isotopic Data ◽

Oceanic Plateaus ◽

Carbon Burial ◽

Organic Carbon Burial ◽

Isotopic Records

The early to mid-Aptian was punctuated by episodic phases of organic-carbon burial in various oceanographic settings, which are possibly related to massive volcanism associated with the emplacement of the Ontong Java, Manihiki, and Hikurangi oceanic plateaus in the southwestern Pacific Ocean, inferred to have formed a single plateau called Ontong Java Nui. Sedimentary osmium (Os) isotopic compositions are one of the best proxies for determining the timing of voluminous submarine volcanic episodes. However, available Os isotopic records during the age are limited to a narrow interval in the earliest Aptian, which is insufficient for the reconstruction of long-term hydrothermal activity. We document the early to mid-Aptian Os isotopic record using pelagic Tethyan sediments deposited in the Poggio le Guaine (Umbria-Marche Basin, Italy) to precisely constrain the timing of massive volcanic episodes and to assess their impact on the marine environment. Our new Os isotopic data reveal three shifts to unradiogenic values, two of which correspond to black shale horizons in the lower to mid-Aptian, namely the Wezel (herein named) and Fallot Levels. These Os isotopic excursions are ascribed to massive inputs of unradiogenic Os to the ocean through hydrothermal activity. Combining the new Os isotopic record with published data from the lowermost Aptian organic-rich interval in the Gorgo a Cerbara section of the Umbria-Marche Basin, it can be inferred that Ontong Java Nui volcanic eruptions persisted for ~5 m.y. during the early to mid-Aptian.

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