Isotopic evidence for microbial sulphate reduction in the early Archaean era

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

53

Scientific paper

Sulphate-reducing microbes affect the modern sulphur cycle, and may be quite ancient, though when they evolved is uncertain. These organisms produce sulphide while oxidizing organic matter or hydrogen with sulphate. At sulphate concentrations greater than 1mM, the sulphides are isotopically fractionated (depleted in 34S) by 10-40‰ compared to the sulphate, with fractionations decreasing to near 0‰ at lower concentrations. The isotope record of sedimentary sulphides shows large fractionations relative to seawater sulphate by 2.7Gyr ago, indicating microbial sulphate reduction. In older rocks, however, much smaller fractionations are of equivocal origin, possibly biogenic but also possibly volcanogenic. Here we report microscopic sulphides in ~3.47-Gyr-old barites from North Pole, Australia, with maximum fractionations of 21.1‰, about a mean of 11.6‰, clearly indicating microbial sulphate reduction. Our results extend the geological record of microbial sulphate reduction back more than 750 million years, and represent direct evidence of an early specific metabolic pathway-allowing time calibration of a deep node on the tree of life.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Isotopic evidence for microbial sulphate reduction in the early Archaean era 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 Isotopic evidence for microbial sulphate reduction in the early Archaean era, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Isotopic evidence for microbial sulphate reduction in the early Archaean era will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1093238

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.