Sidescan sonar imagery of widespread fossil and active cold seeps along the central Chilean continental margin
Klaucke, Ingo, Weinrebe, Reimer Wilhelm, Linke, Peter, Klaeschen, Dirk and Bialas, Jörg (2012) Sidescan sonar imagery of widespread fossil and active cold seeps along the central Chilean continental margin Geo-Marine Letters, 32 . pp. 489-499. DOI 10.1007/s00367-012-0283-1.
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The central Chilean subduction zone between 35°S and 37°S was investigated in order to identify, document and possibly understand fluid flow and fluid venting within the forearc region. Several areas were mapped using multibeam bathymetry and backscatter, high-resolution sidescan sonar, chirp subbottom profiling and reflection seismic data. On a subsequent cruise ground-truthing observations were made using a video sled. In general, this dataset shows surprisingly little evidence of fluid venting along the mid-slope region, in contrast to other subduction zones such as Central America and New Zealand. There were abundant indications of active and predominantly fossil fluid venting along the upper slope between 36.5°S and 36.8°S at the seaward margin of an intraslope basin. Here, backscatter anomalies suggest widespread authigenic carbonate deposits, likely the result of methane-rich fluid expulsion. There is unpublished evidence that these fluids are of biogenic origin and generated within the slope sediments, similar to other accretionary margins but in contrast to the erosional margin off Central America, where fluids have geochemical signals indicating an origin from the subducting plate.
|Keywords:||Marine geology; geophysics; bathymetry; sidescan sonar; cold seeps; Chile; HYDRATE RIDGE; CASCADIA MARGIN; FLUID-FLOW; HIKURANGI MARGIN; NEW-ZEALAND; CARBONATE PRECIPITATION; AUTHIGENIC CARBONATES; ACCRETIONARY PRISMS; CONVERGENT MARGIN; METHANE SEEPAGE|
|Research affiliation:||OceanRep > SFB 574 > A1
OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-MG Marine Geosystems
OceanRep > SFB 574
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Geodynamics
OceanRep > SFB 574 > B3
|Date Deposited:||01 Aug 2011 09:20|
|Last Modified:||07 Jan 2013 11:22|
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