Abstract
The crystallization ages and the Sr and Nd isotopic compositions of groundmass perovskite from a well-established, SE trending, Triassic-Jurassic corridor of kimberlite magmatism in central and eastern North America were determined to investigate the origin of this magmatism. The results obtained from kimberlite fields located along this corridor are interpreted to indicate that at least two distinct mantle sources contributed to this magmatism. The most primitive Rankin Inlet and Timiskaming kimberlites have a relatively unradiogenic strontium isotopic signature (0.7032–0.7036), interpreted to be derived from recycled and metasomatized oceanic lithosphere in the deep mantle. In contrast, the Attawapiskat and Kirkland Lake kimberlites have CHUR-like (Chondritic Uniform Reservoir) signatures (0.7040–0.7042) interpreted to have an origin in the asthenosphere. The progressive decrease in the age of magmatism from the Triassic Rankin Inlet kimberlites to the Miocene Great Meteor seamount, combined with the similarity in the isotopic composition of these diverse magmas along the proposed >3000 km long hot spot track, provides strong evidence in support of a common mantle plume origin for both the continental and oceanic components.
Published Version
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 call