New geochemical and Sr-Nd-Hf isotopic constraints on the genesis of kimberlites and ultramafic lamprophyres from the Adelaide Fold Belt and Gawler Craton, South Australia.

ABSTRACT: This study investigates the geochemical and isotopic characteristics of Jurassic kimberlites and ultramafic lamprophyres (UMLs) from four clusters within the Adelaide Fold Belt (AFB) and two within the Gawler Craton in South Australia. Petrographic analysis, including the occurrence of magmatic clinopyroxene in the groundmass, supported by a review of available mica and spinel compositional data, indicates that many previously classified kimberlites (Eurelia, Angaston and Terowie) are, in fact, ultramafic lamprophyres. New whole-rock major-, trace element and Sr-Nd-Hf isotopic results, augmented by in-situ perovskite and carbonate Sr isotopes, reveal that this sample suite exhibits extensive geochemical variability. These new data highlight the significant role of crustal contamination in

SUBMITTER: Dalton H 

PROVIDER: S-EPMC12672780 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature