We report new examples of Cenozoic cold-seep communities from Colombia, Cuba, the Dominican Republic, Trinidad, and Venezuela, and attempt to improve the stratigraphic dating of Cenozoic Caribbean seep communities using strontium isotope stratigraphy. Two seep faunas are distinguished in Barbados: the late Eocene mudstone-hosted 'Joes River fauna' consists mainly of large lucinid bivalves and t...

We determined the geochemical characteristics of sediments and measured rates of the anaerobic oxidation of methane (AOM) and sulfate reduction (SR) in samples collected near thermogenic (structure II) gas hydrate mounds and in areas lacking hydrates along the continental slope in the Gulf of Mexico. We used radiotracer (C-14 and S-35) techniques to determine rates of AOM and SR over depth in s...

The ability to compare the composition and metabolic potential of microbial communities inhabiting the subsurface sediment in geographically distinct locations is one of the keys to understanding the evolution and function of the subsurface biosphere. Prospective areas for study of the subsurface biosphere are the sites of hydrocarbon discharges on the bottom of the Lake Baikal rift, where asce...

To determine the seepage parameters of surrounding rock during excavation of tunnels, a program of groundwater seepage (SEEP) was developed. Then finite element models are established in SEEP with the consideration of seepage equations for continuous medium, and the correctness was verified by the comparison of FLAC. Moreover, seepage back analysis program (SBAP) was developed in C++ language b...

Modern and Cenozoic deep-sea hydrothermal-vent and methane-seep communities are dominated by large tubeworms, bivalves and gastropods. In contrast, many Early Cretaceous seep communities were dominated by the largest Mesozoic rhynchonellid brachiopod, the dimerelloid Peregrinella, the paleoecologic and evolutionary traits of which are still poorly understood. We investigated the nature of Pereg...

Vesicomyidae clams harbor sulfide-oxidizing endosymbionts and are typical members of cold seep communities where active venting of fluids and gases takes place. We investigated the central biogeochemical processes that supported a vesicomyid clam colony as part of a locally restricted seep community in the Japan Trench at 5346 m water depth, one of the deepest seep settings studied to date. An ...

We sampled the Darwin mud volcano (MV) for meiofaunal community and 14 trophic structure in relation to pore-water geochemistry along a 10-m transect from a seep 15 site on the rim of the crater towards the MV slope. Pore-water profiles indicated 16 considerable variation in upward methane (CH4) flow among sediment cores taken along the 17 transect, with highest flux in the seep sediment core, ...

Riparian zones with extensive groundwater seeps may allow short-circuiting of groundwater to stream channels and modify groundwater contact with shallow organic soil layers in riparian areas. The controls on dissolved organic carbon (DOC) export to an Appalachian headwater stream were examined at Baldwin Creek (southwestern Pennsylvania), where baseflow is derived from multiple surface seeps. D...

Upon their initial discovery, hydrothermal vents and methane seeps were considered to be related but distinct ecosystems, with different distributions, geomorphology, temperatures, geochemical properties and mostly different species. However, subsequently discovered vents and seep systems have blurred this distinction. Here, we report on a composite, hydrothermal seep ecosystem at a subducting ...

In marine sediments the anaerobic oxidation of methane with sulfate as electron acceptor (AOM) is responsible for the removal of a major part of the greenhouse gas methane. AOM is performed by consortia of anaerobic methane-oxidizing archaea (ANME) and their specific partner bacteria. The physiology of these organisms is poorly understood, which is due to their slow growth with doubling times i...