Computer Science
Scientific paper
Jan 2000
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000gecoa..64..233a&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 64, Issue 2, pp.233-246
Computer Science
17
Scientific paper
Sulfate reduction and anaerobic methane oxidation are the dominant microbial processes occurring in hydrate-bearing sediments at bathyal depths in the Gulf of Mexico where crude oil and methane are advecting through fault conduits to the seafloor. The oil and gas seeps are typically overlain by chemosynthetic communities consisting of thiotrophic bacterial mats (Beggiatoa spp .) and methanotrophic mussels (Bathymodiolus spp .), respectively. Cores were recovered with a manned submersible from fine-grained sediments containing dispersed gas hydrates at the threshold of stability. Estimated sulfate reduction rates are variable but generally are substantially higher in crude oil seeps (up to 50 times) and methane seeps (up to 600 times) relative to a non-seep reference sediment (0.0043 mol SO 4 2- cm -3 day -1 ). Sulfur and oxygen isotope fractionation factors are highest in the reference sediment ( S = 1.027; O = 1.015) but substantially lower in the seep sediments ( S = 1.018 to 1.009; O = 1.006 to 1.002) and are controlled primarily by kinetic factors related to sulfate reduction rates. Kinetic effects also control the 34 S/ 18 O ratios such that slow microbial rates yield low ratios whereas faster rates yield progressively higher ratios. The seep data contradict previous claims that 34 S/ 18 O ratios are diagnostic of either microbial sulfate reduction at a fixed 34 S/ 18 O ratio of 4/1 or lower ratios caused by SO 4 -H 2 O equilibration at ambient temperatures. The new results offer a better understanding of methane removal via anaerobic oxidation in the sulfate reduction zone of hydrate-bearing sediments and have significant implications regarding the origin and geochemical history of sedimentary sulfate reconstructed on the basis of 34 S and 18 O compositions.
Aharon Paul
Fu Baoshun
No associations
LandOfFree
Microbial sulfate reduction rates and sulfur and oxygen isotope fractionations at oil and gas seeps in deepwater Gulf of Mexico does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Microbial sulfate reduction rates and sulfur and oxygen isotope fractionations at oil and gas seeps in deepwater Gulf of Mexico, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microbial sulfate reduction rates and sulfur and oxygen isotope fractionations at oil and gas seeps in deepwater Gulf of Mexico will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-806061