Presentation on theme: "Introduction to Metamorphic Petrology Recommended Textbook: J.D. Winter (2001) An Introduction to Igneous and Metamorphic Petrology: Prentice Hall Pub."— Presentation transcript:
Introduction to Metamorphic Petrology Recommended Textbook: J.D. Winter (2001) An Introduction to Igneous and Metamorphic Petrology: Prentice Hall Pub.
Scope of Metamorphic petrology Metamorphic petrology is the study of the subsolidus changes that a rock undergoes when exposed to physicochemical conditions different from those prevailing near the surface of the Earth. Metamorphism produces changes in mineral assemblages and textures that reflect re-equilibration of the rock to the new physicochemical conditions, i.e., minimization of the energy of the system. Metamorphism is commonly isochemical (except for volatile components, e.g., H 2 O, CO 2 ). Where the system is open, the process is referred to as metasomatism.
Metamorphic Reactions Dehydration KAl 3 Si 3 O 10 (OH) 2 + SiO 2 = KAlSi 3 O 8 + AlSi 2 O 5 + H 2 O Decarbonation CaCO 3 + SiO 2 = CaSiO 3 + CO 2 Calcite Quartz Wollastonite Muscovite Quartz K-Feldspar Sillimanite Solid-Solid NaAlSi 3 O 8 = NaAlSi 2 O 6 + SiO 2 Albite Jadeite Quartz
Prograde and Retrograde Metamorphism Prograde Path Retrograde Path
Metamorphic Facies A metamorphic facies is a domain of Pressure-Temperature Space Metamorphic facies are defined by characteristic mineral assemblages specific to particular bulk-rock compositions
Conditions of Metamorphism and Metamorphic Facies