Abstract
The Blake River Group of the late Archean Abitibi Greenstone Belt is characterized by the abundance of differentiated lava series as well as by the presence of coeval tholeiitic and calc-alkaline eruptives. Differentiated tholeiites from this group are interpreted as the product of magma mixing between asthenospheric tholeiites and subduction-related calc-alkaline basaltic andesites. From the lower to the upper southern Abitibi Belt, chemical variations recorded in tholeiites are indicative of a major change in the geodynamic regime. Tholeiites from the lower volcanic sequence were produced by a high degree of partial melting of adiabatically rising diapirs below a rifted lithosphere. Uncontaminated tholeiites from the upper part of the belt reflect a lower degree of partial melting probably due to decreasing lithospheric stretching. This may be related to the closure of the rift-related volcanic basins at the begining of the Kenorean deformational events in the Southern Abitibi Belt.
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.
