Umitaka Spur, situated on an unusual collisional plate boundary along the eastern margin of the Japan Sea, hosts gas seeps, pock-marks, collapse structures, and gas hydrates. Piston cores were recovered from this ridge to understand carbon cycling, pore fluid gradients and authigenic mineralization above a methane-charged system. We present the chemistry of fluids and solids from three cores ad...

*Correspondence: Jeffrey J. Marlow and Victoria J. Orphan, Division of Geological and Planetary Sciences, California Institute of Technology, MC 100-23, Pasadena, CA 91101, USA e-mail: [email protected]; [email protected] Methane seeps are among the most productive habitats along continental margins, as anaerobic methane-oxidizing euryarchaeaota and sulfur-metabolizing deltaproteobacte...

surface oil seeps from alasht, lapur and jenesem share many compositional affinities including distributions and concentrations ofnormal alkanes, terpanes and steranes. these oils also show many similarities with that of jurassic sediments (shemshak group, klarizformation) systematically sampled from the galandrud coal mine. recent geochemical studies in this area indicated that theshemshak gro...

Present-day activity of cold seeps in the ocean is evident from direct observations methane emanating seafloor, presence chemosynthetic organisms, or quantification high gas concentrations sediment pore waters and water column. Verifying past seep biogeochemical characteristics more challenging but may be reconstructed proxy records authigenic carbonates. Here, we investigated lipid-biomarker i...

The origin of modern seafloor methane emissions in the Barents Sea is tightly connected to glacio-tectonic and oceanographic transformations following last ice age. Those regional events induced geological structure re-activation destabilization gas hydrate reservoirs over large areas European continental margins, sustaining widespread fluid plumbing systems. Despite increasing number new activ...

Carbonate communities: The activity of anaerobic methane oxidizing microbes facilitates precipitation of vast quantities of authigenic carbonate at methane seeps. Here we demonstrate the significant role of carbonate rocks in promoting diversity by providing unique habitat and food resources for macrofaunal assemblages at seeps on the Costa Rica margin (400-1850 m). The attendant fauna is surpr...