Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments
Targeted sampling on the Dolgovskoy Mound (northern Shatsky Ridge) revealed the presence of spectacular laterally extensive and differently shaped authigenic carbonates. The sampling stations were selected based on sidescan sonar and profiler images that show patchy backscatter and irregular and dis...
Published in: | Marine and Petroleum Geology |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Elsevier
2008
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Online Access: | https://oceanrep.geomar.de/id/eprint/5200/ https://oceanrep.geomar.de/id/eprint/5200/1/173_Mazzini_2008_ComplexPlumbingSystemsInThe_Artzeit_pubid9798.pdf https://doi.org/10.1016/j.marpetgeo.2007.10.002 |
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ftoceanrep:oai:oceanrep.geomar.de:5200 2023-05-15T18:19:21+02:00 Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments Mazzini, A. Ivanov, M. Nermoen, A. Bahr, André Bohrmann, Gerhard Svensen, H. Planke, S. 2008 text https://oceanrep.geomar.de/id/eprint/5200/ https://oceanrep.geomar.de/id/eprint/5200/1/173_Mazzini_2008_ComplexPlumbingSystemsInThe_Artzeit_pubid9798.pdf https://doi.org/10.1016/j.marpetgeo.2007.10.002 en eng Elsevier https://oceanrep.geomar.de/id/eprint/5200/1/173_Mazzini_2008_ComplexPlumbingSystemsInThe_Artzeit_pubid9798.pdf Mazzini, A., Ivanov, M., Nermoen, A., Bahr, A., Bohrmann, G., Svensen, H. and Planke, S. (2008) Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments. Marine and Petroleum Geology, 25 . pp. 457-472. DOI 10.1016/j.marpetgeo.2007.10.002 <https://doi.org/10.1016/j.marpetgeo.2007.10.002>. doi:10.1016/j.marpetgeo.2007.10.002 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2008 ftoceanrep https://doi.org/10.1016/j.marpetgeo.2007.10.002 2023-04-07T14:50:45Z Targeted sampling on the Dolgovskoy Mound (northern Shatsky Ridge) revealed the presence of spectacular laterally extensive and differently shaped authigenic carbonates. The sampling stations were selected based on sidescan sonar and profiler images that show patchy backscatter and irregular and discontinuous reflections in the near subsurface. The interpretation of acoustic data from the top part of the mound supports the seafloor observations and the sampling that revealed the presence of a complex subsurface plumbing system characterized by carbonates and gas. The crusts sampled consist of carbonate cemented layered hemipelagic sedimentary Unit 1 associated with several centimetres thick microbial mats. Three different carbonate morphologies were observed: (a) tabular slabs, (b) subsurface cavernous carbonates consisting of void chambers up to 20 cm3 in size and (c) chimney and tubular conduits vertically oriented or forming a subhorizontal network in the subsurface. The methanogenic origin of the carbonates is established based on visual observations of fluids seepage structures, 13C depletion of the carbonates (δ13C varying between −36.7‰ and −27.4‰), and by thin carbonate layers present within the thick microbial mats. Laboratory experiments with a Hele–Shaw cell were conducted in order to simulate the gas seepage through contrasting grain size media present on the seafloor. Combined petrography, visual observations and sandbox simulations allowed a characterization of the dynamics and the structures of the plumbing system in the near subsurface. Based on sample observations and the experiments, three observed morphologies of authigenic carbonates are interpreted, respectively, as (a) Darcian porous flow through the finely laminated clayey/coccolith-rich layers, (b) gas accumulation chambers at sites where significant fluid escape was impeded by thicker clayey layers forming the laminated Unit1 and (c) focussed vertical fluid venting and subhorizontal migration of overpressured fluids released from (b). ... Article in Journal/Newspaper Shatsky ridge OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Marine and Petroleum Geology 25 6 457 472 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
Targeted sampling on the Dolgovskoy Mound (northern Shatsky Ridge) revealed the presence of spectacular laterally extensive and differently shaped authigenic carbonates. The sampling stations were selected based on sidescan sonar and profiler images that show patchy backscatter and irregular and discontinuous reflections in the near subsurface. The interpretation of acoustic data from the top part of the mound supports the seafloor observations and the sampling that revealed the presence of a complex subsurface plumbing system characterized by carbonates and gas. The crusts sampled consist of carbonate cemented layered hemipelagic sedimentary Unit 1 associated with several centimetres thick microbial mats. Three different carbonate morphologies were observed: (a) tabular slabs, (b) subsurface cavernous carbonates consisting of void chambers up to 20 cm3 in size and (c) chimney and tubular conduits vertically oriented or forming a subhorizontal network in the subsurface. The methanogenic origin of the carbonates is established based on visual observations of fluids seepage structures, 13C depletion of the carbonates (δ13C varying between −36.7‰ and −27.4‰), and by thin carbonate layers present within the thick microbial mats. Laboratory experiments with a Hele–Shaw cell were conducted in order to simulate the gas seepage through contrasting grain size media present on the seafloor. Combined petrography, visual observations and sandbox simulations allowed a characterization of the dynamics and the structures of the plumbing system in the near subsurface. Based on sample observations and the experiments, three observed morphologies of authigenic carbonates are interpreted, respectively, as (a) Darcian porous flow through the finely laminated clayey/coccolith-rich layers, (b) gas accumulation chambers at sites where significant fluid escape was impeded by thicker clayey layers forming the laminated Unit1 and (c) focussed vertical fluid venting and subhorizontal migration of overpressured fluids released from (b). ... |
format |
Article in Journal/Newspaper |
author |
Mazzini, A. Ivanov, M. Nermoen, A. Bahr, André Bohrmann, Gerhard Svensen, H. Planke, S. |
spellingShingle |
Mazzini, A. Ivanov, M. Nermoen, A. Bahr, André Bohrmann, Gerhard Svensen, H. Planke, S. Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments |
author_facet |
Mazzini, A. Ivanov, M. Nermoen, A. Bahr, André Bohrmann, Gerhard Svensen, H. Planke, S. |
author_sort |
Mazzini, A. |
title |
Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments |
title_short |
Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments |
title_full |
Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments |
title_fullStr |
Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments |
title_full_unstemmed |
Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments |
title_sort |
complex plumbing systems in the near subsurface: geometries of authigenic carbonates from dolgovskoy mound (black sea) constrained by analogue experiments |
publisher |
Elsevier |
publishDate |
2008 |
url |
https://oceanrep.geomar.de/id/eprint/5200/ https://oceanrep.geomar.de/id/eprint/5200/1/173_Mazzini_2008_ComplexPlumbingSystemsInThe_Artzeit_pubid9798.pdf https://doi.org/10.1016/j.marpetgeo.2007.10.002 |
genre |
Shatsky ridge |
genre_facet |
Shatsky ridge |
op_relation |
https://oceanrep.geomar.de/id/eprint/5200/1/173_Mazzini_2008_ComplexPlumbingSystemsInThe_Artzeit_pubid9798.pdf Mazzini, A., Ivanov, M., Nermoen, A., Bahr, A., Bohrmann, G., Svensen, H. and Planke, S. (2008) Complex plumbing systems in the near subsurface: geometries of authigenic carbonates from Dolgovskoy Mound (Black Sea) constrained by analogue experiments. Marine and Petroleum Geology, 25 . pp. 457-472. DOI 10.1016/j.marpetgeo.2007.10.002 <https://doi.org/10.1016/j.marpetgeo.2007.10.002>. doi:10.1016/j.marpetgeo.2007.10.002 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.marpetgeo.2007.10.002 |
container_title |
Marine and Petroleum Geology |
container_volume |
25 |
container_issue |
6 |
container_start_page |
457 |
op_container_end_page |
472 |
_version_ |
1766196416624984064 |