Mechanisms and processes leading to reverse zoning in the Andong granitoid pluton, Andong batholith, Korea

The Andong batholith is a Jurassic plutonic complex intruding metamorphic rocks of the RRyeongnam massif that extends from NE to SW in the southern Korean Peninsula. Detailed mapping and petrographic studies show that the batholith exhibits five sparate plutons: Andong, Dosan, Pungsan, Imha, and Nokjeon. The oldest Andong pluton among them exhibits reverse zoning. This feature contrasts with typical modal and chemical zoning trends in calc-alkaline plutons in which higher color index and more mafic rocks in the outer rim surround lower color index felsic rocks in the interior. (omitted)