Methane cold seep systems typically exhibit extensive buildups of authigenic carbonate minerals, resulting from local increases in alkalinity driven by methane oxidation. Here, we demonstrate that modern seep authigenic carbonates exhibit anomalously low clumped isotope values (Δ47), as much as ∼0.2‰ lower than expected values. In modern seeps, this range of disequilibrium translates into appar...

The importance of tectonics and fluid flow in controlling cold seep habitats has long been appreciated at convergent margins but remains poorly understood in strike-slip systems. Here we present geophysical, geochemical, and biological data from an activemethane seep offshore fromDelMar, California, in the inner California borderlands (ICB). The location of this seep appears controlled by local...

Prolific natural hydrocarbon seepage occurs offshore of Coal Oil Point in the Santa Barbara Channel, California. Within the water column above submarine vents, plumes of hydrocarbon gas bubbles act as acoustic scattering targets. Using 3.5 kHz sonar data, seep distribution offshore of Coal Oil Point was mapped for August 1996, July 1995, and July 1973. Comparison of the seep distributions over ...

UNLABELLED Marine methane seeps are globally distributed geologic features in which reduced fluids, including methane, are advected upward from the subsurface. As a result of alkalinity generation during sulfate-coupled methane oxidation, authigenic carbonates form slabs, nodules, and extensive pavements. These carbonates shape the landscape within methane seeps, persist long after methane flux...

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...

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...