|
|
|
|
| |
|
|
| De Prunele, Alexis; Ruffine, Livio; Riboulot, Vincent; Peters, Carl A.; Croguennec, Claire; Guyader, Vivien; Pape, Thomas; Bollinger, Claire; Bayon, Germain; Caprais, Jean-claude; Germain, Yoan; Donval, Jean-pierre; Marsset, Tania; Bohrmann, Gerhard; Geli, Louis; Rabiu, Abdulkarim; Lescanne, Marc; Cauquil, Eric; Sultan, Nabil. |
| The Niger Delta is one of the largest hydrocarbon basin offshore Africa and it is well known for the presence of active pockmarks on the seabed. During the Guineco-MeBo cruise in 2011, long cores were taken from a pockmark cluster in order to investigate the state of its current activity. Gas hydrates, oil and pore-water were sampled for geochemical studies. The resulting dataset combined with seismic data reveal that shallow hydrocarbon migration in the upper sedimentary section was focused exclusively within the pockmarks. There is a clear tendency for gas migration within the hydrate-bearing pockmarks, and oil migration within the carbonate-rich one. This trend is interpreted as a consequence of hydrate dissolution followed by carbonate precipitation... |
| Tipo: Text |
Palavras-chave: Anaerobic oxidation of methane; Cluster of pockmarks; Fluid flow; Gas hydrates; Pore-water profiles; Transient state. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00365/47647/47676.pdf |
| |
|
|
| Ruffine, Livio; Caprais, Jean-claude; Bayon, Germain; Riboulot, Vincent; Donval, Jean-pierre; Etoubleau, Joel; Birot, Dominique; Pignet, Patricia; Rongemaille, Emmanuelle; Chazallon, Bertrand; Grimaud, Sylvie; Adamy, Jerome; Charlou, Jean-luc; Voisset, Michel. |
| A joint industrial project with IFREMER and Total provides insights into the tectonic setting and the geochemistry of a large active pockmark offshore W-Africa in the Niger Delta. The study combines both geophysical (seismic) and geochemical data to infer the dynamics of a 300 m wide pockmark located at 667 m water depth. Two Calypso cores, one at the centre and one outside the pockmark, along with three box-cores, two inside the pockmark and one outside, were collected to study the geochemistry of gas hydrates, carbonates and pore waters. Two seismic lines, a 3D high resolution random line and a 2D high resolution seismic line, provide a good description of the plumbing of the system. The integrated results depict a very active pockmark characterized by... |
| Tipo: Text |
Palavras-chave: Active pockmark; Anaerobic oxidation of methane; Gas hydrates; Carbonates; Seismic surveys; Fault system; U/Th dating. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00139/24981/23102.pdf |
| |
|
|
| Akhoudas, C.; Chevalier, N.; Blanc-valleron, M. -m.; Klein, V.; Mendez-millan, M.; Demange, J.; Dalliah, S.; Rommevaux, V.; Boudouma, O.; Pierre, C.; Ruffine, Livio. |
| Cold seeps along the North Anatolian fault in the Sea of Marmara (Turkey) were explored during submersible dives of the Marsite cruise in November 2014 when sediments, pore waters and carbonate crusts were sampled at active fluid seeping sites. In this study, we investigate the mineralogy, carbon and oxygen isotopic compositions and the lipid biomarkers of a carbonate crust from the western Tekirdağ basin of the Sea of Marmara. This crust exhibits a laminated domal structure that resembles stromatolite. The mineralogy of authigenic seep-carbonate is mostly represented by aragonite associated with minor amounts of high-magnesian calcite. The abundance of pyrite associated with the authigenic seep-carbonate points to very intense bacterial sulfate reduction.... |
| Tipo: Text |
Palavras-chave: Marmara Sea; Tekirdag Basin; Methane; Authigenic seep-carbonate; Sulfate reduction; Anaerobic oxidation of methane; Stromatolitic structure; Stable isotopes; Lipid biomarkers. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00417/52857/53764.pdf |
| |
|
|
| Ruffine, Livio; Germain, Yoan; Polonia, Alina; De Prunele, Alexis; Croguennec, Claire; Donval, Jean-pierre; Pitel-roudaut, Mathilde; Ponzevera, Emmanuel; Caprais, Jean-claude; Brandily, Christophe; Grall, Celine; Bollinger, Claire; Geli, Louis; Gasperini, Luca. |
| Within the Sea of Marmara, the highly active North Anatolian Fault (NAF) is responsible for major earthquakes (Mw>=7), and acts as a pathway for fluid migration from deep sources to the seafloor. This work reports on pore water geochemistry from three sediment cores collected in the Gulfs of Izmit and Gemlik, along the Northern and the Middle strands of the NAF, respectively. The resulting data set shows that anaerobic oxidation of methane (AOM) is the major process responsible for sulfate depletion in the shallow sediment. In the Gulf of Gemlik, depth concentration profiles of both sulfate and alkalinity exhibit a kink-type profile. The Sulfate Methane Transition Zone (SMTZ) is located at moderate depth in the area. In the Gulf of Izmit, the low... |
| Tipo: Text |
Palavras-chave: Anaerobic oxidation of methane; North Anatolian Fault; Pore water geochemistry; Sea of Marmara; Seismic activity. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00272/38339/36570.pdf |
| |
|
|
| Chuang, Pei-chuan; Dale, Andrew W.; Wallmann, Klaus; Haeckel, Matthias; Yang, Tsanyao Frank; Chen, Nai-chen; Chen, Hsiao-chi; Chen, Hsuan-wen; Lin, Saulwood; Sun, Chih-hsien; You, Chen-feng; Horng, Chorng-shern; Wang, Yunshuen; Chung, San-hsiung. |
| Geochemical data (CH4, SO42-, I-, Cl-, particulate organic carbon (POC), C-13-CH4, and C-13-CO2) are presented from the upper 30 m of marine sediment on a tectonic submarine accretionary wedge offshore southwest Taiwan. The sampling stations covered three ridges (Tai-Nan, Yung-An, and Good Weather), each characterized by bottom simulating reflectors, acoustic turbidity, and different types of faulting and anticlines. Sulfate and iodide concentrations varied little from seawater-like values in the upper 1-3 m of sediment at all stations; a feature that is consistent with irrigation of seawater by gas bubbles rising through the soft surface sediments. Below this depth, sulfate was rapidly consumed within 5-10 m by anaerobic oxidation of methane (AOM) at the... |
| Tipo: Text |
Palavras-chave: Gas hydrate; Methane flux; Bubble irrigation; Anaerobic oxidation of methane; POC degradation; Accretionary wedge; Taiwan. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37514/35843.pdf |
| |
|
|
| Teichert, B. M. A.; Chevalier, N.; Gussone, N.; Bayon, Germain; Ponzevera, Emmanuel; Ruffine, Livio; Strauss, H.. |
| During the MARSITECruise expedition in November 2014 on board the RV Pourquoi Pas?, multidisciplinary sampling was carried out with the ROV Victor 6000 in order to investigate biogeochemical processes taking place at cold seep environments in the Sea of Marmara. Pore water, bottom water, sediment and authigenic carbonate samples were collected from two short push cores (MRS-DV5-PC04 − 8 cm, MRS-DV5-PC01 − 12.5 cm) at an active methane bubbling site in the southeastern part of the Çinarcik Basin. Sulfate sulfur and oxygen isotope data as well as sulfide isotope data indicate that sulfate-dependent anaerobic oxidation of methane is the dominant process in the sediments. This is confirmed by archaeal lipids diagnostic for anaerobic methane oxidizers detected... |
| Tipo: Text |
Palavras-chave: Sea of Marmara; Cinarcik Basin; Methane; Sulfate reduction; Anaerobic oxidation of methane; Authigenic carbonate; Lipid biomarker. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00413/52480/53267.pdf |
| |
|
|
| Wang, Xudong; Li, Niu; Feng, Dong; Hu, Yu; Bayon, Germain; Liang, Qianyong; Tong, Hongpeng; Gong, Shanggui; Tao, Jun; Chen, Duofu. |
| Cold seeps frequently occur at the seafloor along continental margins. The dominant biogeochemical processes at cold seeps are the combined anaerobic oxidation of methane and sulfate reduction, which can significantly impact the global carbon and sulfur cycles. The circulation of methane-rich fluids at margins is highly variable in time and space, and assessing past seepage activity requires the use of specific geochemical markers. In this study, we report multiple sedimentary proxy records for three piston gravity cores (QDN-14A, QDN-14B, and QDN-31) from the Haima seep of the South China Sea (SCS). By combining total organic carbon (TOC), total inorganic carbon (TIC), total nitrogen (TN), total sulfur (TS), acid insoluble carbon and sulfur isotope... |
| Tipo: Text |
Palavras-chave: Cold seep; Anaerobic oxidation of methane; Carbon and sulfur isotopes; South China Sea. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00465/57662/59858.pdf |
| |
|
|
|
