scholarly journals Redox condition and organic carbon accumulation mechanism in the Cryogenian Nanhua Basin, South China: Insights from iron chemistry and sulfur, carbon, oxygen isotopes of the Datangpo Formation

2018 ◽  
Vol 3 (1) ◽  
pp. 67-75
Author(s):  
Chaoyong Wang ◽  
Guanzhong Shi
Keyword(s):  
Organic Carbon ◽  
Oxygen Isotopes ◽  
South China ◽  
Carbon Accumulation ◽  
Redox Condition ◽  
Accumulation Mechanism ◽  
Iron Chemistry

Marinoan glacial aftermath in South China: Paleo-environmental evolution and organic carbon accumulation in the Doushantuo shales

2020 ◽  
Vol 555 ◽  
pp. 119838 ◽  
Author(s):  
Wenyao Xiao ◽  
Jian Cao ◽  
Bing Luo ◽  
Yuan He ◽  
Gang Zhou ◽  
...  
Keyword(s):  
Organic Carbon ◽  
South China ◽  
Carbon Accumulation ◽  
Environmental Evolution

Siberian Trap volcanism, global warming and the Permian-Triassic mass extinction: New insights from Armenian Permian-Triassic sections

2019 ◽  
Vol 132 (1-2) ◽  
pp. 427-443 ◽  
Author(s):  
M.M. Joachimski ◽  
A.S. Alekseev ◽  
A. Grigoryan ◽  
Yu.A. Gatovsky
Keyword(s):  
Global Warming ◽  
Organic Carbon ◽  
Oxygen Isotopes ◽  
Climate Warming ◽  
South China ◽  
Mass Extinction ◽  
Time Interval ◽  
Triassic Boundary ◽  
Volcanic Event ◽  
Siberian Trap

Abstract Permian-Triassic boundary sections from Armenia were studied for carbon isotopes of carbonates as well as oxygen isotopes of conodont apatite in order to constrain the global significance of earlier reported variations in the isotope proxies and elaborate the temporal relationship between carbon cycle changes, global warming and Siberian Trap volcanism. Carbon isotope records of the Chanakhchi and Vedi II sections show a 3–5‰ negative excursion that start in the Clarkina nodosa (C. yini) conodont Zone (latest Permian) with minimum values recorded in Hindeodus parvus to Isarcicella isarcica conodont zones (earliest Triassic). Sea surface temperatures (SST) reconstructed from oxygen isotopes of conodont apatite increase by 8–10 °C over an extrapolated time interval of ∼39 ka with the onset of global warming occurring in the C. iranica (C. meishanensis) Zone of the latest Permian. Climate warming documented in the Armenian sections is comparable to published time-equivalent shifts in SST in Iran and South China suggesting that this temperature change represents a true global signature. By correlating the Armenian and Iranian section with the radiometrically well-dated Meishan GSSP (Global Stratotype Section and Point) section (South China), the negative shift in δ13C is estimated to have occurred 12–128 ka prior to the onset of global warming. This temporal offset is unexpected given the synchrony in changes in atmospheric CO2 and global temperature as seen in Pleistocene ice core records. The negative δ13C excursion is explained by the addition of emission of isotopically light CO2 and CH4 from thermogenic heating of organic carbon-rich sediments by Siberian Trap sill intrusions. However, the observed time lag in the δ13C and δ18O shifts questions the generally assumed cause-effect relationship between emission of thermogenically produced greenhouse gases and global warming. The onset of temperature rise coincides with a significant enrichment in Hg/TOC (total organic carbon) ratios arguing for a major volcanic event at the base of the extinction interval. Whether global warming was a major factor for the Late Permian mass extinction depends on the duration of the extinction interval. Warming only starts at the base of the extinction interval, but with the extinction encompassing a time interval of 60 ± 48 ka, global climate warming in conjunction with temperature-related stressors as hypoxia and reduced nutrient availability may have been one of the major triggers of the most devastating biotic crisis in Earth history.

Changes in sediment and organic carbon accumulation in a highly-disturbed ecosystem: The Sacramento-San Joaquin River Delta (California, USA)

2009 ◽  
Vol 59 (4-7) ◽  
pp. 154-163 ◽  
Author(s):  
Elizabeth A. Canuel ◽  
Elizabeth J. Lerberg ◽  
Rebecca M. Dickhut ◽  
Steven A. Kuehl ◽  
Thomas S. Bianchi ◽  
...  
Keyword(s):  
Organic Carbon ◽  
River Delta ◽  
Carbon Accumulation ◽  
San Joaquin River

scholarly journals Organic mulching promotes soil organic carbon accumulation to deep soil layer in an urban plantation forest

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaodan Sun ◽  
Gang Wang ◽  
Qingxu Ma ◽  
Jiahui Liao ◽  
Dong Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Fine Roots ◽  
Soil Layer ◽  
Carbon Accumulation ◽  
Bulk Soil ◽  
Organic Mulch ◽  
The Impact ◽  
Soc Fractions

Abstract Background Soil organic carbon (SOC) is important for soil quality and fertility in forest ecosystems. Labile SOC fractions are sensitive to environmental changes, which reflect the impact of short-term internal and external management measures on the soil carbon pool. Organic mulching (OM) alters the soil environment and promotes plant growth. However, little is known about the responses of SOC fractions in rhizosphere or bulk soil to OM in urban forests and its correlation with carbon composition in plants. Methods A one-year field experiment with four treatments (OM at 0, 5, 10, and 20 cm thicknesses) was conducted in a 15-year-old Ligustrum lucidum plantation. Changes in the SOC fractions in the rhizosphere and bulk soil; the carbon content in the plant fine roots, leaves, and organic mulch; and several soil physicochemical properties were measured. The relationships between SOC fractions and the measured variables were analysed. Results The OM treatments had no significant effect on the SOC fractions, except for the dissolved organic carbon (DOC). OM promoted the movement of SOC to deeper soil because of the increased carbon content in fine roots of subsoil. There were significant correlations between DOC and microbial biomass carbon and SOC and easily oxidised organic carbon. The OM had a greater effect on organic carbon fractions in the bulk soil than in the rhizosphere. The thinnest (5 cm) mulching layers showed the most rapid carbon decomposition over time. The time after OM had the greatest effect on the SOC fractions, followed by soil layer. Conclusions The frequent addition of small amounts of organic mulch increased SOC accumulation in the present study. OM is a potential management model to enhance soil organic matter storage for maintaining urban forest productivity.

Organic Carbon Isotope Geochemistry of the Neoproterozoic Doushantuo Formation, South China

2010 ◽  
Vol 80 (5) ◽  
pp. 670-683 ◽  
Author(s):  
GUO Qingjun ◽  
LIU Congqiang ◽  
Harald STRAUSS ◽  
Tatiana GOLDBERG ◽  
ZHU Maoyan ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Isotope ◽  
South China ◽  
Isotope Geochemistry ◽  
Doushantuo Formation ◽  
Organic Carbon Isotope
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