Some observations on the origins of large volumes of carbon dioxide accumulations in sedimentary basins

Wycherley, H. L.; Fleet, Andrew; Shaw, H. F.

doi:10.1016/s0264-8172(99)00047-1

Cited by 132 publications

(63 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For example, calcium carbonate will decompose with high temperature from regional and contact metamorphism into calcium oxide and carbon dioxide when heated: CaCO 3 →CaO + CO 2 . The following papers have more details on the origin of carbon dioxide from the thermal breakdown of carbonates in sedimentary basins: Giggenbach [23], Imbus et al [22], and Wycherley et al [24].…”

Section: Thermal Cracking Of Inorganic Materialsmentioning

confidence: 99%

Evaluation of Near-Surface Gases in Marine Sediments to Assess Subsurface Petroleum Gas Generation and Entrapment

Abrams

2017

Geosciences

View full text Add to dashboard Cite

Gases contained within near-surface marine sediments can be derived from multiple sources: shallow microbial activity, thermal cracking of organic matter and inorganic materials, or magmatic-mantle degassing. Each origin will display a distinctive hydrocarbon and non-hydrocarbon composition as well as compound-specific isotope signature and thus the interpretation of origin should be relatively straightforward. Unfortunately, this is not always the case due to in situ microbial alteration, non-equilibrium phase partitioning, mixing, and fractionation related to the gas extraction method. Sediment gases can reside in the interstitial spaces, bound to mineral or organic surfaces and/or entrapped in carbonate inclusions. The interstitial sediment gases are contained within the sediment pore space, either dissolved in the pore waters (solute) or as free (vapour) gas. The bound gases are believed to be attached to organic and/or mineral surfaces, entrapped in structured water or entrapped in authigenic carbonate inclusions. The purpose of this paper is to provide a review of the gas types found within shallow marine sediments and examine issues related to gas sampling and extraction. In addition, the paper will discuss how to recognise mixing, alteration and fractionation issues to best interpret the seabed geochemical results and determine gas origin to assess subsurface petroleum gas generation and entrapment.

show abstract

Section: Thermal Cracking Of Inorganic Materialsmentioning

confidence: 99%

Evaluation of Near-Surface Gases in Marine Sediments to Assess Subsurface Petroleum Gas Generation and Entrapment

Abrams

2017

Geosciences

View full text Add to dashboard Cite

show abstract

“…δ 13 C-CO 2 values likewise suggest that carbon dioxide in the vent gas primarily originates from the degradation of kerogen and soluble organic matter (Dai et al, 1996;Irwin et al, 1977;Wycherley et al, 1999). A potential source rock for primary gas formation is the Late Oligocene-Lower Miocene Maikop series, which comprises significant amounts of type II kerogen (Efendiyeva, 2004), and is located at 1-4 km depth in the Eastern Black Sea (Banks et al, 1997;Meredith and Egan, 2002).…”

Section: Station Nomentioning

confidence: 99%

Molecular and isotopic partitioning of low-molecular-weight hydrocarbons during migration and gas hydrate precipitation in deposits of a high-flux seepage site

et al. 2010

View full text Add to dashboard Cite

Detailed knowledge of the extent of post-genetic modifications affecting shallow submarine hydrocarbons fueled from the deep subsurface is fundamental for evaluating source and reservoir properties. We investigated gases from a submarine high-flux seepage site in the anoxic Eastern Black Sea in order to elucidate molecular and isotopic alterations of low-molecular-weight hydrocarbons (LMWHC) associated with upward migration through the sediment and precipitation of shallow gas hydrates. For this, nearsurface sediment pressure cores and free gas venting from the seafloor were collected using autoclave technology at the Batumi seep area at 845 m water depth within the gas hydrate stability zone. Vent gas, gas from pressure core degassing, and from hydrate dissociation were strongly dominated by methane (> 99.85 mol.% of ∑[C 1 -C 4 , CO 2 ]). Molecular ratios of LMWHC (C 1 /[C 2 + C 3 ] > 1000) and stable isotopic compositions of methane (δ 13 C = − 53.5‰ V-PDB; D/H around − 175‰ SMOW) indicated predominant microbial methane formation. C 1 /C 2+ ratios and stable isotopic compositions of LMWHC distinguished three gas types prevailing in the seepage area. Vent gas discharged into bottom waters was depleted in methane by > 0.03 mol.% (∑[C 1 -C 4 , CO 2 ]) relative to the other gas types and the virtual lack of 14 C-CH 4 indicated a negligible input of methane from degradation of fresh organic matter. Of all gas types analyzed, vent gas was least affected by molecular fractionation, thus, its origin from the deep subsurface rather than from decomposing hydrates in near-surface sediments is likely. As a result of the anaerobic oxidation of methane, LMWHC in pressure cores in top sediments included smaller methane fractions [0.03 mol.% ∑(C 1 -C 4 , CO 2 )] than gas released from pressure cores of more deeply buried sediments, where the fraction of methane was maximal due to its preferential incorporation in hydrate lattices. No indications for stable carbon isotopic fractionations of methane during hydrate crystallization from vent gas were found. Enrichments of 14 C-CH 4 (1.4 pMC) in short cores relative to lower abundances (max. 0.6 pMC) in gas from long cores and gas hydrates substantiates recent methanogenesis utilizing modern organic matter deposited in top sediments of this high-flux hydrocarbon seep area.

show abstract

“…Ballentine, 1997;Jenden et al, 1993;Sherwood Lollar et al, 1994, 1997Wycherley et al, 1999). Isotopic compositions of mantle-derived carbon are indeed contained between −3 and −8‰ Pee Dee Belemnite (PDB) and isotopic compositions of bulk crustal carbon correspond to a range of −5 to −7‰ PDB.…”

Section: Principlesmentioning

confidence: 99%

The Relevance of Geochemical Tools to Monitor Deep Geological CO2 Storage Sites

Jeandel¹

2012

Geochemistry - Earth's System Processes

View full text Add to dashboard Cite

Some observations on the origins of large volumes of carbon dioxide accumulations in sedimentary basins

Cited by 132 publications

References 11 publications

Evaluation of Near-Surface Gases in Marine Sediments to Assess Subsurface Petroleum Gas Generation and Entrapment

Evaluation of Near-Surface Gases in Marine Sediments to Assess Subsurface Petroleum Gas Generation and Entrapment

Molecular and isotopic partitioning of low-molecular-weight hydrocarbons during migration and gas hydrate precipitation in deposits of a high-flux seepage site

The Relevance of Geochemical Tools to Monitor Deep Geological CO2 Storage Sites

Contact Info

Product

Resources

About