Abstract

The mechanism for generating plagioclase-supersaturated basic magma is crucial to the origin and evolution of massif anorthosites. A model is proposed to explain their temporal and tectonic association, invoking iterative plagioclase accumulation, magma mixing, and phenocryst resorption to produce plagioclase-supersaturated parent liquids. By analogy to mid-ocean ridge systems, the model invokes periodic replenishment of magma reservoirs in an environment of incipient or very slow dilation. These conditions are believed to characterize anorogenic anorthosite complexes.

First Page Preview

First page PDF preview
You do not currently have access to this article.