Tracing the origin of carbonaceous matter and apatite in Neoarchean banded iron formations from Abitibi

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

5225 Early Environment Of Earth, 5410 Composition (1060, 3672), 5455 Origin And Evolution

Scientific paper

The low metamorphic grade of Neoarchean banded iron formations (BIFs) from Abitibi, Québec, allows for the study of BIFs with minimal post-depositional alteration. Biological oxidation of ferrous iron has been suggested as a possible process by which BIFs form and if correct, organic remains of these microbial communities may be preserved within such sedimentary rocks. An investigation of the organic carbon in the BIFs from this region was performed to determine the mode of its occurrence and its association with apatite, which can form from the diagenetic maturation of organic remains. In a thin section of jasper-magnetite-chert BIF, two grains of apatite were found to exist in association with organic carbon, whereas the other grains are associated with carbonate, magnetite and hematite. These observations were confirmed via Raman spectroscopy and SEM. Carbonaceous material associated with apatite is characterized by D- and G-band peak intensities consistent with the metamorphic history of these rocks. Carbon isotopic compositions and concentrations were determined on several micro-drilled areas on various BIF thick sections, representing the mineral diversity of the samples. The δ13C values range between -15 to -45 ‰ (δ13Caverage = -29.2 ‰; n = 67), and the average organic content was 0.25% (range between 0.04 and 1.00 %;). Significant carbon isotope fractionations with large negative δ13C values could be biological in origin, but abiological processes could also be responsible for these ranges. Our observations in the studied BIFs collectively suggest that this organic matter was part of the original depositional environment and that apatite and carbonate likely formed during diagenesis.

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

Tracing the origin of carbonaceous matter and apatite in Neoarchean banded iron formations from Abitibi 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 Tracing the origin of carbonaceous matter and apatite in Neoarchean banded iron formations from Abitibi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tracing the origin of carbonaceous matter and apatite in Neoarchean banded iron formations from Abitibi will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1238876

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