In one scenario for mineral fractionation between volcanic and plutonic rocks, eruptible felsic melt ... the presence of extreme outliers (for example, several orders of magnitude farther from ...

Keller and colleagues 1 report one of the most compelling examples ... of plutonic rocks (which formed from magmas that slowly cooled within the Earth) with those of volcanic rocks (formed when ...

either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.