Carbonate Associated Sulfate in a Stromatolite from the Eocene Green River Formation

Details Carbonate Associated Sulfate in a Stromatolite from the Eocene Green River Formation Carbonate Associated Sulfate in a Stromatolite from the Eocene Green River Formation

Dec 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agufm.p51a1401f&link_type=abstract

American Geophysical Union, Fall Meeting 2008, abstract #P51A-1401

Biology

0400 Biogeosciences, 0448 Geomicrobiology, 1055 Organic And Biogenic Geochemistry

Scientific paper

We measured the carbonate associated sulfate (CAS: sulfate trapped in the carbonate crystal lattice at the time of precipitation) in a ~51 myo stromatolite from the Tipton-Wilkins Peak contact in the Greater Green River Basin in southern Wyoming. The 8-cm-thick microdigitate stromatolite contained two alternating microstructures: a precipitated carbonate fan fabric and a micritic fabric (including trapped detrital grains). CAS values for the precipitated layers clustered narrowly between 392-431ppm; given the precipitated fabric, we suggest that CAS reflects lake chemistry at the time of formation. Adjacent micritic layers, on the other hand, had much greater variation (321-3479ppm) and substantially higher average values per layer (519- 1170ppm); we hypothesize that these values probably may not represent actual lake evaporative environments, the likely source of the micrite. We used average CAS values in the precipitated layers to estimate sulfate concentrations in the Greater Green River Basin at the time of carbonate formation using a CAS vs. sulfate concentration relationship established in a modern analog system at Walker Lake, Nevada. Our analysis suggests that lake sulfate was ~1.5mM, implying a moderate level of sulfate. Better constraints on the rate of carbonate formation and the depth-to-volume relationships of the lake basin are required before quantitative lake depth fluctuation calculations can be done. In lakes where this information is well-constrained, CAS could be used to determine lake volume fluctuations on relatively fine timescales. However, care is required to ensure that grains tested are representative of the in situ environment (e.g. not detrital or shell material).

Affiliated with

Also associated with

No associations

Rating

Carbonate Associated Sulfate in a Stromatolite from the Eocene Green River Formation 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 Carbonate Associated Sulfate in a Stromatolite from the Eocene Green River Formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carbonate Associated Sulfate in a Stromatolite from the Eocene Green River Formation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1239091