Organic Carbon Burial in the Aral Sea of Central Asia

The burial of organic carbon in lake sediments plays an important role in the terrestrial carbon cycle. Clarifying the current status of carbon burial in the lakes of Central Asia is of great significance for the application of carbon balance assessments. With the analysis of the total organic carbon and nitrogen and the carbon isotope and organic carbon burial rate in the core sediment of the North Aral Sea, the status and influencing factors of organic carbon burial over the past 70 years can be revealed. The results showed that the main source of organic carbon was predominantly from lacustrine aquatic plants. However, the contribution of terrigenous organic carbon increased from the 1950s to the 1960s. The burial rate of organic carbon in North Aral Sea sediments was consistent with the overall change in the regional temperature. The burial rate of organic carbon showed an upward trend as a whole with an average of 28.78 g·m−2·a−1. Since 2010, the burial rate of organic carbon has stood at the highest level in nearly 70 years, with an average of 55.66 g·m−2·a−1. The protection of a lake by human beings can not only significantly improve the lake’s aquatic ecosystem but also help to increase the burial rate of the lake’s organic carbon.

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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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"OAE 3" – regional Atlantic organic carbon burial during the Coniacian–Santonian

Climate of the Past ◽

10.5194/cp-8-1447-2012 ◽

2012 ◽

Vol 8 (5) ◽

pp. 1447-1455 ◽

Cited By ~ 46

Author(s):

M. Wagreich

Keyword(s):

Organic Carbon ◽

Temporal Distribution ◽

Black Shales ◽

Time Interval ◽

Temporal And Spatial Distribution ◽

Oceanic Anoxic Event ◽

The North ◽

Carbon Burial ◽

Organic Carbon Burial ◽

Anoxic Event

Abstract. The Coniacian–Santonian time interval is the inferred time of oceanic anoxic event 3 (OAE 3), the last of the Cretaceous OAEs. A detailed look on the temporal and spatial distribution of organic-rich deposits attributed to OAE 3 suggests that black shale occurrences are restricted to the equatorial to mid-latitudinal Atlantic and adjacent basins, shelves and epicontinental seas like parts of the Caribbean, the Maracaibo Basin and the Western Interior Basin, and are largely absent in the Tethys, the North Atlantic, the southern South Atlantic, and the Pacific. Here, oxic bottom waters prevailed as indicated by the widespread occurrence of red deep-marine CORBs (Cretaceous Oceanic Red Beds). Widespread CORB sedimentation started during the Turonian after Oceanic Anoxic Event 2 (OAE 2) except in the Atlantic realm where organic-rich strata continue up to the Santonian. The temporal distribution of black shales attributed to OAE 3 indicates that organic-rich strata do not define a single and distinct short-time event, but are distributed over a longer time span and occur in different basins during different times. This suggests intermittent and regional anoxic conditions from the Coniacian to the Santonian. A comparison of time-correlated high-resolution δ13C curves for this interval indicates several minor positive excursions of up to 0.5‰, probably as a result of massive organic carbon burial cycles in the Atlantic. Regional wind-induced upwelling and restricted deep basins may have contributed to the development of anoxia during a time interval of widespread oxic conditions, thus highlighting the regional character of inferred OAE 3 as regional Atlantic event(s).

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Recent sediment accumulation and organic carbon burial in the North Sea sediment

GFF ◽

10.1080/11035899609546383 ◽

1996 ◽

Vol 118 (sup004) ◽

pp. 81-81

Author(s):

H. De Haas

Keyword(s):

Organic Carbon ◽

North Sea ◽

Sediment Accumulation ◽

Recent Sediment ◽

The North ◽

Carbon Burial ◽

Organic Carbon Burial ◽

The North Sea

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Recent sedimentation and organic carbon burial in a shelf sea: the North Sea

Marine Geology ◽

10.1016/s0025-3227(97)00082-0 ◽

1997 ◽

Vol 144 (1-3) ◽

pp. 131-146 ◽

Cited By ~ 41

Author(s):

Henk de Haas ◽

Wim Boer ◽

Tjeerd C.E. van Weering

Keyword(s):

Organic Carbon ◽

North Sea ◽

The North ◽

Carbon Burial ◽

Organic Carbon Burial ◽

Shelf Sea ◽

The North Sea

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Sediment Organic Carbon Sequestration of Balkhash Lake in Central Asia

Sustainability ◽

10.3390/su13179958 ◽

2021 ◽

Vol 13 (17) ◽

pp. 9958

Author(s):

Wen Liu ◽

Long Ma ◽

Jilili Abuduwaili ◽

Gulnura Issanova ◽

Galymzhan Saparov

Keyword(s):

Carbon Sequestration ◽

Organic Carbon ◽

The Past ◽

Burial Rate ◽

Carbon Burial ◽

Sediment Organic Carbon ◽

Organic Carbon Burial ◽

Organic Carbon Burial Rate ◽

Organic Carbon Sequestration ◽

Global Carbon

As an important part of the global carbon pool, lake carbon is of great significance in the global carbon cycle. Based on a study of the sedimentary proxies of Balkhash Lake, Central Asia’s largest lake, changes in the organic carbon sequestration in the lake sediments and their possible influence over the past 150 years were studied. The results suggested that the organic carbon in the sediments of Lake Balkhash comes mainly from aquatic plants. The organic carbon burial rate fluctuated from 8.16 to 30.04 g·m−2·a−1 and the minimum appeared at the top of the core. The organic carbon burial rate continues to decline as it has over the past 150 years. Global warming, higher hydrodynamic force, and low terrestrial input have not been conducive to the improvement of organic carbon sequestration in Balkhash Lake; the construction of a large reservoir had a greater impact on the sedimentary proxy of total organic carbon content, which could lead to a large deviation for environmental reconstruction. This is the first study to assess the sediment organic carbon sequestration using the modern sediments of Central Asia’s largest lake, which is of great scientific significance. The results contribute to an understanding of organic carbon sequestration in Central Asia and may provide a scientific basis for carbon balance assessment in regional and global scales.

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Enhanced Terrestrial Runoff during Oceanic Anoxic Event 2 on the North Carolina Coastal Plain, USA

10.5194/cp-2021-25 ◽

2021 ◽

Author(s):

Christopher M. Lowery ◽

Jean M. Self-Trail ◽

Craig D. Barrie

Keyword(s):

North Carolina ◽

Organic Carbon ◽

Coastal Plain ◽

Hydrologic Cycle ◽

Oceanic Anoxic Event ◽

The North ◽

Carbon Burial ◽

Organic Carbon Burial ◽

Oceanic Anoxic Event 2 ◽

Anoxic Event

Abstract. A global increase in the strength of the hydrologic cycle drove an increase in flux of terrigenous sediments into the ocean during the Cenomanian-Turonian Oceanic Anoxic Event 2 (OAE2) and was an important mechanism driving nutrient enrichment and thus organic carbon burial. This global change is primarily known from isotopic records, but global average data don't tell us anything about changes at any particular location; such reconstructions of local terrigenous flux can help us understand the role of regional shifts in precipitation in driving these global trends. The North Atlantic basin was one of the epicenters of enhanced organic carbon burial during OAE2, and so constraining terrigenous flux is particularly important in this region; however, few local records exist. Here, we present two new OAE2 records from the Atlantic Coastal Plain of North Carolina, USA, recognized with calcareous nannoplankton biostratigraphy and organic carbon isotopes. We use carbon/nitrogen ratios to constrain the relative contribution of marine and terrestrial organic matter; in both cores we find elevated contribution from vascular plants beginning just before OAE2 and continuing through the event, indicating a locally strengthened hydrologic cycle. Terrigenous flux decreased during the brief change in carbon isotope values known as the Plenus carbon isotope excursion, and then increase and remain elevated through the latter part of OAE2. Total organic carbon values reveal relatively low organic carbon burial in the inner shelf, in contrast to black shales known from the open ocean. Organic carbon content on the shelf appears to increase in the offshore direction, highlighting the need for cores from the middle and outer shelf.

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Organic carbon burial rate and the molybdenum proxy: Theoretical framework and application to Cenomanian-Turonian oceanic anoxic event 2

Paleoceanography ◽

10.1029/2004pa001068 ◽

2005 ◽

Vol 20 (2) ◽

pp. n/a-n/a ◽

Cited By ~ 67

Author(s):

Stephen R. Meyers ◽

Bradley B. Sageman ◽

Timothy W. Lyons

Keyword(s):

Organic Carbon ◽

Theoretical Framework ◽

Oceanic Anoxic Event ◽

Burial Rate ◽

Carbon Burial ◽

Organic Carbon Burial ◽

Oceanic Anoxic Event 2 ◽

Anoxic Event ◽

Organic Carbon Burial Rate

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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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