NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Isotopic, petrologic and biogeochemical investigations of banded iron-formationsIt is recognized that the first occurrence of banded iron-formations (BIFs) clearly predates biological oxygenation of the atmosphere-hydrosphere system and that their last occurrences extend beyond plausible dates of pervasive biological oxygenation. For this reason, and because enormous quantities of oxidizing power have been sequestered in them, it is widely thought that these massive, but enigmatic, sediments must encode information about the mechanism and timing of the rise of atmospheric O2. By coupling isotopic analyses of iron-formation carbonates with biogeochemical and petrologic investigations, we are studying (1) the mechanism of initial sedimentation of iron; (2) the role of iron in microbially mediated diagenetic processes in fresh iron-formation sediments; and (3) the logical integration of mechanisms of deposition with observed levels of banding. Thus far, it has been shown that (1) carbonates in BIFs of the Hamersley Group of Western Australia are isotopically inhomogenous; (2) the nature and pattern of isotopic ordering is not consistent with a metamorphic origin for the overall depletion of C-13 observed in the carbonates; (3) if biological, the origin of the C-13 depleted carbonate could be either respiratory or fermentative; (4) iron may have been precipitate d as Fe(3+), then reduced to Fe(2+) within the sediment; and (5) sedimentary biogeochemical systems may have been at least partially closed to mass transport of carbonate species.
Document ID
19860017413
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Hayes, J. M.
(Indiana Univ. Bloomington, IN, United States)
Kaufman, A. J.
(Indiana Univ. Bloomington, IN, United States)
Klein, C.
(New Mexico Univ. Albuquerque, United States)
Studley, S. A.
(Indiana Univ. Bloomington, IN, United States)
Baur, M. E.
(California Univ. Los Angeles, United States)
Walter, M. R.
(Bureau of Mineral Resources Geology and Geophysics, Canberra, Australia)
Date Acquired
August 12, 2013
Publication Date
May 1, 1986
Publication Information
Publication: NASA, Washington Second Symposium on Chemical Evolution and the Origin and Evolution of Life
Subject Category
Space Biology
Accession Number
86N26885
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available