Petrology Midterm I Powerpoints 1-8 Quizzes 1-3 Homework 1-2 Winter Chapters 1-10

1) Introduction to Igneous Petrology and Earth’s Physical and Chemical Structure Milestones to an understanding of igneous processes Chemical and Physical Structure of the Earth Heat Sources, heat transfer mechanisms and geothermal gradients Relationships of mantle dynamics and plate tectonics

2) Classification of Igneous Rocks Goals of a classification scheme Essential minerals to ultramafic, mafic and felsic modal classification schemes Normalization of modes for a ternary diagram Other modifiers for a complete description of an igneous rock Significance of bulk rock textures in gabbros – ophitic vs. intergranular The good and the bad of modal classification schemes Utility of cumulate classification schemes Chemical classification of volcanic Classifications of volcaniclastic rocks

3) Physical Igneous Petrology Physical and chemical properties of 4 main classes of lavas Contrast in eruptive character of basalts vs. intermed/felsic lavas Distinguishing subaerial from submarine basalt eruptions 3 types of pyroclastic deposits Intrusion shape types Styles and mechanisms of magma emplacement at different crustal depths

4) Introduction to Thermodynamics What is Thermodynamics? 3 states of energy – unstable, metastable, stable What is Gibbs Free Energy and why is pertinent to igneous systems? What are the main variables controlling G? What are intrinsic vs. extrinsic variables Reference state conditions for measuring G Understand why melting curves in P-T space have a positive slope (related to P-V and T-S relationships)

5) One- and Two-Component Phase Diagrams Empirical and experimental evidence on how magmas crystallize Basic parameters of Phase Diagrams (P, T, X) Gibbs Phase Rule and determining the degrees of freedom on phase diagrams One-component systems – Qtz, H 2 O Two-component systems with Solid Solution – An-Ab, Fo-Fa Two-component systems with a Eutectic – Di-An Two-component systems with a Peritectic – Fo(-En)-Qtz (extra credit) The lever rule in determining the % of liquid and solid during equilibrium crystallization Understand how processes of melting and crystallization can be portrayed on binary phase diagrams.

6) Multi-component Phase Diagrams An-Fo-Di ternary system Understand how equilibrium melting and crystallization are portrayed Understand how the lever rule is used to determine the proportion and compositions of solid phases and the liquid Understand the rocks formed due to equilibrium crystallization vs. fractional crystallization

7) Major, Minor and Trace Element Chemistry General major, minor, and trace element constituents of a basalt General compositional differences between mafic and felsic magmas What CIPW norms are used for X-Y Harker diagrams – indicators of magmatic differentiation in magmatic series AFM diagrams – discriminate what? Difference between HFSE and LIL trace elements Concept of trace element compatibility and definition of mineral- liquid partition coefficients Behavior of REE during partial melting and fractional crystallization

8) Mantle Melting and the Generation of Basaltic Magma Lherzolitic composition of the mantle Variation in the aluminous phase with depth – Pl – Sp – Gt Geothermal gradients compared to mantle melting curves 3 ways to get the mantle to melt – increase T, adiabatic decompression, increased volatiles. 5 ways to create compositional diversity among mafic magmas