The influence of methane fluxes on the sulfate/methane interface in sediments from the Rio Grande Cone Gas Hydrate Province, southern Brazil

• DOI: 10.1590/2317-4889201720170027
• Publication Date: 2017-10-30T19:39:16Z
• Authors: Luiz Frederico Ro...; João Marcelo Ketzer; Rogerio Véscia Lo...; Adolpho Herbert A...; Gesiane Sbrissa; Dennis Miller; Roberto Heemann; Adriano Viana; Antonio Fernando ...; Sadoon Morad
• Keywords: Authigenic; Clathrate hydrate

ABSTRACT: Much research has been published regarding the relation between major gas hydrate accumulations and global carbon cycle. In this context, determination of sulfate/methane interface (SMI) depth is primary importance in order to understand dynamics methane flux shallow section. This paper identifies SMI sediments based on sulfate concentration profiles cores recovered Rio Grande Cone Gas Hydrate Province, Pelotas Basin, southern Brazil. The shape can be linked local rate as follows: (i) near linear, high upward-diffusing coupled with diffusion from seawater; (ii) irregular, variable rates; (iii) kink-type profile, which indicative rather than strictly upward flux. areas a was identified are spatially associated chimneys within pockmarks, whereas low present adjacent areas. These appear acoustic blankings seismic records therefore mapped subsurface. wavy-like reflection following coincides occurrence authigenic carbonate nodules concretions. addition, fluxes concretions carbonates were correlated by stratigraphic position bearing intervals profiles.