DSpace JSPUI

Late Neogene Deep-Sea Benthic Foraminifera From Blake Ridge Gas Hydrate (Odp Holes 994c And 997a), Nw Atlantic Ocean.: Methane is a powerful greenhouse gas and an important climate driver that may have played a significant role in climate change in the geological past. Destabilization of gas hydrates as well as frozen methane stored on the ocean floor and in permafrost may have provided important source of methane to the atmosphere. Presence of methane within the marine sediments plays an important role in shaping benthic foraminiferal population and isotopic fractionation of marine carbonates. Certain species of benthic foraminifera feeding on bacterial rich food source and high negative δ13C of marine carbonates are the two important proxies for the presence of methane rich environment. Ocean Drilling Program Holes 994C (water depth 2799 m) and 997A (water depth 2770 m) are located on the crest of the Blake Outer Ridge (BOR) – a well proven gas hydrate field, ~200 Km off the east coast of the United States of America in the northwestern Atlantic Ocean. At present, this area lies underlies the periphery of the subtropical central gyre and is under the profound influence of the northerly flowing, warm, saline, Gulf Stream surface current as well as the southerly flowing high velocity Western Boundary Under Current (WBUC). BOR is a large sediment drift deposit having high sedimentation rate, is tectonically inactive since the late Cenozoic and is a proven potentially large gas hydrate reservoir. The disseminated gas hydrate rich sediments lie between ~ 185 to ~450 meter below sea floor having methane rich sediments below and methane free sediments above. This area thus offers good opportunities to analyze benthic foraminifer faunal-methane relationship as well as paleoceanographic and paleoclimatic changes during the late Neogene, along with methane flux history and genesis of gas hydrate.