Mineral Chemistry of Mildly Alkalic Basalts from the 25 Ma Mont Crozier Section, Kerguelen Archipelago: Constraints on Phenocryst Crystallization Environments

Abstract

interface, which became deeper as a result of progressive crustal Phenocryst compositions and mineral-melt equilibria in the mildly thickening as the archipelago moved from a ridge-centered setting at alkalic basalts from the 25 Ma Mont Crozier section on the >40 Ma to an intraplate position by 25 Ma. Kerguelen Archipelago are used to estimate the depths at which magmas stalled and crystallized and to constrain the role of crustal structure in the evolution of magmas produced by the Kerguelen mantle plume. The Crozier section, of nearly 1000 m height,