Ab-An Binary vs. Water Pressure Johannes, 1978; Morse, 1980

Hypersolvus vs. Subsolvus Granites Yoder et al., 1957; Morse, 1970

An-Ab-Kfsp Ternary - Flattened An-Kfsp Binary An-Ab Binary Ab-Kfsp Binary Nekvasil & Lindsley, 1990; Brown, 1993

Intersection of Liquidus Surfaces Temperature falls from E toward M in Thermal Valley

An-Ab-Kfsp Perspective Solvus or Miscibility Gap

Feldspar Tielines Smith & Carmichael, 1969; Fuhrman & Lindsley, 1988; Best et al., 1995 Rhyolite Pumice Trachybasalt

An-Ab-Kfsp Ternary Liquid Line of Descent

Water Saturated Granite System

Effect of Pressure and Granite Modes

Origin of Granitoids Phase equilibria support either that granitoids are either the end product of fractional crystallization of a mafic parent or the partial melt generated from the melting of sialic crust - large corresponding extrusive equivalents suggests large magma chambers of equivalent composition. Field relations suggest that large plutons have diffuse boundaries and many seem to show variable and locally pervasive overprint of subsolidus recrystallization indicative of metamorphic origin.

Granitic System Liquid Line of Descent Initial Bulk Composition

Pyroxene Quadrilateral

Mica and Amphibole - Melt Equilibria Wones & Eugster, 1965

Thermal Stability of Volatile Minerals thermal energy + volatile-rich mineral = volatile-free or volatile-poor mineral(s) + volatile fluid

Assessing States of Equilibrium Isolated anhedral grains that resulted from partial resorption or dissolution into the melt Reaction rims of one or more phases surrounding another anhedral crystalline phase. Compositionally zoned grains originate through incomplete reaction relations within a single solid solutions, e.g. plagioclase. Presence of minerals or a mineral assemblage that is known to be unstable or unlikely in an evolutionary sense, e.g. Mg-olivine and qtz together. Disequilibrium states are suggested by the following: