border facies

border facies

[′bȯrd·ər ‚fā·shēz]
(geology)
The outer portion of an igneous intrusion which differs in composition and texture from the main body.
References in periodicals archive ?
The Sant' Andrea facies is exposed most abundantly along the northwestern margin of the pluton, but also occurs as scattered patches elsewhere, which led early workers to refer to it as the border facies (Marinelli 1959).
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