Abstract
Sm-Nd, Rb-Sr and K-Ar isotope analyses were made on argillaceous sediments from the Gunflint Iron Formation in the Lake Superior region, in order to provide new information on their sedimentation age and evolutionary history. The investigations indicate that it might be possible to date the time of sedimentation by the Sm-Nd method by studying specific material, such as argillaceous whole-rocks enriched in organic matter and clay fractions. The spread in the Sm-Nd ratios seems here to have been favoured by the incorporation of organic material in the argillites. The Sm-Nd isotope data yield an isochron age of 2.08 ± 0.25 Ga, which seems to be a fair estimation of deposition age. Model calculations indicate that the main source supplying the Animikie seawater with REE was located at the northern border of the basin. The argillites and their clay minerals did not behave as closed systems with regard to the Rb-Sr and K-Ar systems during further diagenetic evolution.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
