Efficient trapping of organic carbon in sediments on the continental margin with high fluvial sediment input off southwestern Taiwan

2006 ◽  
Vol 26 (20) ◽  
pp. 2520-2537 ◽  
Author(s):  
Shuh-Ji Kao ◽  
Fuh-Kwo Shiah ◽  
Chung-Ho Wang ◽  
Kon-Kee Liu
Keyword(s):  
Organic Carbon ◽  
Continental Margin ◽  
Fluvial Sediment ◽  
Sediment Input ◽  
Southwestern Taiwan

Organic carbon oxidation and preservation in NW Atlantic continental margin sediments

1987 ◽  
Vol 31 (1) ◽  
pp. 215-236 ◽  
Author(s):  
D. Heggie ◽  
C. Maris ◽  
A. Hudson ◽  
J. Dymond ◽  
R. Beach ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Continental Margin ◽  
Carbon Oxidation ◽  
Organic Carbon Oxidation

scholarly journals Relationships between grain size and organic carbon 14C heterogeneity in continental margin sediments

2019 ◽  
Vol 505 ◽  
pp. 76-85 ◽  
Author(s):  
Rui Bao ◽  
Thomas M. Blattmann ◽  
Cameron McIntyre ◽  
Meixun Zhao ◽  
Timothy I. Eglinton
Keyword(s):  
Grain Size ◽  
Organic Carbon ◽  
Continental Margin

scholarly journals Fluvial Sediment Transit Time Regulates the Fate of Organic Carbon between Source and Sink

2020 ◽  
Author(s):  
Marisa Repasch ◽  
Joel Scheingross ◽  
Niels Hovius ◽  
Hella Wittmann ◽  
Maarten Lupker ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Transit Time ◽  
Fluvial Sediment ◽  
Source And Sink

Dispersal and transformation of organic carbon across an episodic, high sediment discharge continental margin, Waipaoa Sedimentary System, New Zealand

2010 ◽  
Vol 270 (1-4) ◽  
pp. 202-212 ◽  
Author(s):  
Hannah L. Brackley ◽  
Neal E. Blair ◽  
Noel A. Trustrum ◽  
Lionel Carter ◽  
Elana L. Leithold ◽  
...  
Keyword(s):  
New Zealand ◽  
Organic Carbon ◽  
Continental Margin ◽  
Sediment Discharge ◽  
Sedimentary System ◽  
High Sediment

Quantifying and characterising organic carbon in newly-developed soils following glacier retreat in northern latitudes

2020 ◽  
Author(s):  
Saule Akhmetkaliyeva ◽  
Robert Sparkes ◽  
Leon Clarke ◽  
Andrew Dean ◽  
Simon Cook
Keyword(s):  
Organic Carbon ◽  
Dna Sequencing ◽  
Soil Development ◽  
Glacier Retreat ◽  
The Arctic ◽  
Glacial Meltwater ◽  
Fluvial Sediment ◽  
Sediment Samples ◽  
Glacier Front ◽  
Soil And Sediment

<p>Arctic and sub-arctic regions contain a globally significant reservoir of easily degradable glacial organic carbon (GOC) held within glacier ice, subglacial sediments, and proglacial sediments and soils. 21st century warming will result in global glacier retreat with the potential to expose and release GOC, degradation of which can produce CO<sub>2</sub> and/or CH<sub>4</sub> through physical, chemical or biological processes. Newly-exposed nutrient rich glacial landscapes may develop soils and ecosystems. However, current understanding of the nature of glacial carbon cycling is very weak. In this study, sources and transformations of organic carbon (OC) within proglacial environments were determined using a combination of organic biomarkers, DNA sequencing and elemental concentrations.</p><p>Soil development was characterised in three contrasting glacial systems (Oræfajökull ice cap in Iceland, Tarfala in Sweden and Zackenberg in Greenland) in order to understand the main source of OC in soils exposed after glacier retreat and soil development along downstream transects from the glacier front. Water, soil and sediment samples were collected during four successful field campaigns (Iceland and Sweden in summer 2018, Greenland and Iceland in summer 2019). Soil and sediment samples were analysed for organic carbon and nitrogen concentrations, bacteriohopanepolyol biomarkers (BHPs), a group of membrane lipids that can be used to trace major microbial groups, DNA sequencing and major elements (using ICP-OES and IC).  </p><p>Soil samples from moraines showed highest OC concentrations (up to 5.5% in Iceland), while fluvial sediment samples from all study areas had low to no OC. BHPs were rare in fluvial sediments, observed in riverbank soils and most common in moraines. Both total BHP concentration and R’soil index (up to 50.5 µg/g ΣBHPs in a Little Ice Age and 0.41 R’soil in a 2500-year-old Icelandic moraines) show development of soils over time along the downstream transect from the glacier front. DNA concentrations in soil extracts are much higher than fluvial sediment samples. Particulate OC concentration in glacial meltwater streams and proglacial lakes was low (up to 0.03 mg/L), perhaps due to the high total suspended sediment concentrations (up to 0.96 mg/L) in most of the streams. Water chemistry analyses showed significant Ca, S, Na, Fe, Mg and Al concentrations, that potentially would fertilise the Arctic Ocean.</p><p>Based on these preliminary data, it can be concluded that direct glacial output of organic carbon is low, but soil and ecosystem development in front of retreating glaciers leads to the build-up of new terrestrial OC stores. Erosion of OC from these pro-glacial landscapes by glacial meltwater might highly affect estimates of GOC. Future glacier retreat in deglaciating systems in the Arctic (Greenland and Sweden) and sub-arctic (Iceland) regions might increase terrestrial OC productivity and carbon export, as well as seeding biological production downstream.</p>

Element partitioning in ferruginous and pyritic phosphorite from the continental margin off Morocco

1978 ◽  
Vol 42 (322) ◽  
pp. 221-228 ◽  
Author(s):  
J. M. McArthur
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Continental Shelf ◽  
Continental Margin ◽  
Major Elements ◽  
Element Partitioning ◽  
Carbonate Fluorapatite

SummaryPhosphorites from the continental shelf off Morocco have been analysed for major elements and Fe, Mn, V, Cu, Ni, Zn, As, Na, Sr, S, and for carbonate. In pyritic phosphorites Cu, Ni, Zn, and As are present mainly in minor pyrite and organic carbon. In ferruginous phosphorites As, Mn, and V are associated with goethite. In the ferruginous phosphorites Cu, Ni, and Zn may have been introduced in association with organic matter and pyrite during phosphorite formation and been retained during subsequent destruction of these phases by weathering. In all phosphorites Na and Sr are present mainly in carbonate-fluorapatite. Sulphur in the ferru-ginous phosphorites occurs only in carbonate-fluorapatite. In the pyritic samples it is partitioned between pyrite and francolite (carbonate-fluorapatite).

scholarly journals A two-dimensional model of the passive coastal margin deep sedimentary carbon and methane cycles

2012 ◽  
Vol 9 (8) ◽  
pp. 2859-2878 ◽  
Author(s):  
D. E. Archer ◽  
B. A. Buffett ◽  
P. C. McGuire
Keyword(s):  
Organic Carbon ◽  
Pore Water ◽  
Continental Margin ◽  
Methane Production ◽  
Production Efficiency ◽  
Dissolved Inorganic Carbon ◽  
Carbon Isotopic Composition ◽  
Scale Model ◽  
Dimensional Model ◽  
Sediment Column

Abstract. We present a new geologic-time and basin-spatial scale model of the continental margin methane cycle. The model, SpongeBOB, is used to simulate evolution of the carbon cycle in a passive sedimentary continental margin in response to changing oceanographic and geologic forcing over a time scale of 200 million years. The geochemistry of the sediment column is altered by the addition of vertical high-permeability channels intended to mimic the effects of heterogeneity in the real sediment column due to faults, and produces results consistent with measured pore-water tracers SO42− and 129I. Pore water dissolved inorganic carbon (DIC) concentrations are consistent with chemical weathering (CaCO3 formation from igneous rocks) at depth within the sediment column. The carbon isotopic composition of the DIC is consistent with a methane production efficiency from particulate organic carbon (POC) of 50%, which is somewhat lower than redox balance with the H / C of organic matter in the model. The hydrate inventory in the model is somewhat less sensitive to temperature than our previous results with a one-dimensional model, quite sensitive to reasonable changes in POC, and extremely sensitive to the ability of methane bubbles to rise within the sediment column, and how far gas-phase methane can get through the sediment column before it redissolves when it reaches undersaturated conditions. Hydrate formation is also sensitive to deep respiration of migrating petroleum. Other phenomena which we simulated had only a small impact on the hydrate inventory, including thermogenic methane production and production/decomposition of dissolved organic carbon.

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