9. Regional and Subduction Facies Flashcards
What are the metamorphic facies series for contact, mountain belt and subduction zone metamorphism?
Contact: zeolite → hornfels
Mountain Belt: zeolite → prehnite-pumpellyite → greenschist → amphibolite → granulite
Subduction Zone: zeolite → blueschist → eclogite
What is a metamorphic Facies Series?
a sequence of metamorphic facies encountered in a traverse across a metamorphic terrain
Why could a P-T array lie between mountain belt and contact metamorphism?
Higher temps than mountain belt, could be due to imput of extra heat from magmatic intrusions e.g. in a continental arc
What is a pressure-temperature-time path? (P-T-t)
The complete set of P-T conditions that a rock may experience during a metamorphic cycle from burial to metamorphism to uplift and erosion
Diagnostic Mineral Parageneses in Zeolite
Ca-zeolites + Na-zeolites
Diagnostic Mineral Parageneses in Prehnite pumpellyite
prehnite + pumpellyite
Diagnostic Mineral Parageneses in Greenschist
actinolite + albite + epidote + chlorite
Diagnostic Mineral Parageneses in Albite-epidote amphibolite
hornblende + albite +epidote
Diagnostic Mineral Parageneses in Amphibolite
hornblende + plagioclase
Diagnostic Mineral Parageneses in Granulite
augite + opx + plagioclase + garnet
Diagnostic Mineral Parageneses in Blueschist
glaucophane + lawsonite/epidote
Diagnostic Mineral Parageneses in Eclogite
garnet + omphacite + quartz
Diagnostic Mineral Parageneses in Pyroxene Hornfels
augite + opx + plagioclase
Diagnostic Mineral Parageneses in Sanidinite
augite + pigeonite + plagioclase
What is the Mountain Belt Facies series?
zeolite → prehnite-pumpellyite → greenschist → amphibolite → granulite
What is the Subduction Zone Facies series?
zeolite → blueschist → eclogite
