12.109 Petrology

Fall 2005

The texture of intergrown feldspar and quartz granite known as "graphic granite" has often been compared to cuneiform writing. (Image courtesy of MIT OCW.)

Course Highlights

This course features lecture notes and laboratory exercises.

Course Description

This undergraduate petrology course surveys the distribution, chemical composition, and mineral associations in rocks of the earth's crust and upper mantle, and establishes its relation to tectonic environment. The emphasis of the course is on the use of chemistry and physics to interpret rock forming processes.

Technical Requirements

Special software is required to use some of the files in this course: .xls.

Syllabus

Description

12.109 is a broad survey of igneous and metamorphic petrology. The course follows the history and development of the field as well as the scientific methods and findings. Students learn the relationships between rock-forming processes, tectonic environments, and the chemical composition and texture of rocks.

Topics Include

Dynamics of Crust and Mantle Melting as Preserved in the Chemical Composition of Igneous Rocks and Minerals
The Long-term Record of Global Climate Change as Preserved in the Minerals of Sedimentary Rocks
Time-temperature-depth Record Preserved in Minerals of Metamorphosed Crustal Rocks

Prerequisites

Structure of Earth Materials (12.108), Thermodynamics of Materials (3.00) recommended

Labs

Labs are due one week after they are assigned. The microscope and hand sample lab room is reserved for six hours per week; however, anytime the room is open, feel free to go in and look at thin sections/rocks. See your TA with questions, and work together if needed. All students must turn in their own work.

Grading

Grading criteria.
ACTIVITIES	PERCENTAGES
Lab: Exercises, Midterm, and Final Exam	50%
Lecture: 3 Problem Sets, Midterm, and Final Exam	50%

All exams on lecture material will be closed book. The lab final is open book.

Calendar

Course calendar.
SES #	LECTURE TOPICS	LAB TOPICS	KEY DATES
Rock Forming Minerals (RFM)
1	RFM I: Olivine and Spinel	Microscope Introduction
2	RFM II: Feldspars	Minerals I
3	RFM III: Pyroxenes	Minerals I
4	RFM IV: Pyriboles	Minerals II
Thermodynamics
5	1-Energy Functions-E-S-V and G-T-P-X	Minerals II
6	P-T-X Phase Diagrams Gibbs Phase Rule	Minerals III
7	2-Exchange Reactions and Equilibrium Constants	Textures	Problem set 1: Exchange reactions
8	3-Earth's Outer Mantle - Phase Relations and Variation with Tectonic Setting	Mantle Rocks
Petrology
9	Mantle Rock Types and Processes Pyroxene Thermobarometry	Basalt
10	Serpentine Stability - Recycling of Mantle Origin of Mantle Rocks - Igneous vs. Metamorphic Processes	Lab Review
11	4-Melting and Crystallization Processes T-X-X Phase Diagrams (3 Components) Freezing/Melting in Crust and Mantle	Lab Midterm Exam	Problem set 2: Using phase diagrams
12	5-Basalts, Komatiites Rock Series Mantle Melting Processes
13	Midterm Exam
14	6-Phase Equilibria: Silicate + H₂O Magma Generation in Subduction Zones	Calc-alkaline Rocks
15	7-Granitic Rocks and Crustal Magmatic Processes	Granite
16	Continental Crustal Igneous Rocks
17	The Major Types of Sedimentary Rocks Distribution of Sediments on the Earth's Surface	Sedimentary Rocks
18	Metamorphic Petrology 1 - Metamorphic Processes, Contact, Regional, T and P Variations	Metamorphic Minerals
19	Metamorphic Petrology 2 - Metamorphic Facies Heat Flow and Heat Production in Crust
20	Metamorphic Petrology 3 - Metamorphism of Pelitic Rocks Minerals and Isograds	Metamorphic Facies
21	Metamorphic Petrology 4 - Pelites - The AKFM System Continuous and Discontinuous Reactions	Pelites	Problem set 3: Garnet-biotite thermobarometry
22	Metamorphic Petrology 5 - Metamorphism of Mafic Rocks, Metamorphism
23	Greenschists, Blueschists and Eclogites	Lab Review
24	Metamorphic Petrology 6 - Metamorphism of calc-silicates	Lab Final Exam

Readings

Primary Texts

Hess, P. C. Origin of Igneous Rocks. Cambridge, MA: Harvard University Press, 1989. ISBN: 0674644816.

Spear, F. S. Metamorphic Phase Equilibria and Pressure - Temperature - Time Paths. Chantilly, VA: Mineralogical Society of America, 1993. ISBN: 0939950340.

Supplemental Reading Material

Bloss, F. D. An Introduction to the Methods of Optical Crystallography. New York, NY: Holt, Rinehart and Winston, 1961.

Boggs, S., Jr. Petrology of Sedimentary Rocks. New York, NY: MacMillan, 1992.

Boyd, F. R., et al. "Evidence for a 150-200-km thick Archaean lithosphere from diamond inclusion thermobarometry." Geochim Cosmochim Acta 37 (1973): 2533-2546.

Compton, R. R. Manual of Field Geology. New York, NY: John Wiley and Sons, 1962.

Roeder, P. L., and R. F. Emslie. "Olivine-liquid equilibrium." Contrib Mineral Petrol 29 (1970): 275-289.

Wood, B. J., and D. G. Fraser. Elementary Thermodynamics for Geologists. New York, NY: Oxford University Press, 1977.

Recommended Resources for Laboratory Exercises

The Microsoft® Powerpoint® lecture on optical mineralogy is an excellent primer on the physics of using a microscope in mineralogy.

See especially Microsoft® Powerpoint® presentation 3 for helpful information on twinning, cleavage, and more in thin sections.

Deer, W. A., R. A. Howie, and J. Zussman. An Introduction to the Rock-Forming Minerals. 2nd ed. New York, NY: Longman Scientific and Technical, 1992.

McKenzie, W. S., C. H. Donaldson, and C. Guilford. Atlas of Igneous Rocks and their Textures. New York, NY: Wiley, 1982.

McKenzie, W. S., and C. Guilford. Atlas of Rock-Forming Minerals in Thin Section. New York, NY: Wiley, 1979.

Nesse, W. D. Introduction to Optical Mineralogy. New York, NY: Oxford University Press, 1991.

Troger, W. E. Optical Determination of Rock Forming Minerals. Part 1, E. Stuttgart, Deutschland: Schweizerbartische Verlagsbuchhandlung, 1979.

Williams, H., F. J. Turner, and C. M. Gilbert. Petrography, An Introduction to the Study of Rocks. 2nd ed. New York, NY: W.H. Freeman and Co., 1982.

Readings by Session

Course readings.
SES #	TOPICS	READINGS
Rock Forming Minerals (RFM)
1	(RFM) I Olivine and Spinel
2	RFM II: Feldspars
3	RFM III Pyroxenes
4	RFM IV Pyriboles
Thermodynamics
5	1-Energy Functions-E-S-V and G-T-P-X	Spear. pp. 133-146, 175-183.
6	P-T-X Phase Diagrams Gibbs Phase Rule	Spear. pp. 247-288.
7	2-Exchange Reactions and Equilibrium Constants	Roeder and Emslie.
8	3-Earth's Outer Mantle - Phase Relations and Variation with Tectonic Setting	Hess. Chapter 6.
Petrology
9	Mantle Rock Types and Processes Pyroxene Thermobarometry	Boyd. Wood and Fraser. pp. 134-139.
10	Serpentine Stability - Recycling of Mantle Origin of Mantle Rocks - Igneous vs. Metamorphic Processes
11	4-Melting and Crystallization Processes T-X-X Phase Diagrams (3 Components) Freezing/Melting in Crust and Mantle	Hess. Chapter 2.
12	5-Basalts, Komatiites Rock Series Mantle Melting Processes	Hess. Chapters 8, 9, and 18.
13	Mid-term
14	6-Phase Equilibria: Silicate + H₂O Magma Generation in Subduction Zones	Hess. Chapter 10.
15	7-Granitic Rocks and Crustal Magmatic Processes	Hess. Chapter 15.
16	Continental Crustal Igneous Rocks
17	The Major Types of Sedimentary Rocks Distribution of Sediments on the Earth's Surface	Boggs. Chapter 1.
18	Metamorphic Petrology 1 - Metamorphic Processes, Contact, Regional, T and P Variations	Spear. Chapter 1.
19	Metamorphic Petrology 2 - Metamorphic Facies Heat Flow and Heat Production in Crust	Spear. Chapter 2. ———. Chapter 3.
20	Metamorphic Petrology 3 - Metamorphism of Pelitic Rocks Minerals and Isograds	Spear. Chapter 10.
21	Metamorphic Petrology 4 - Pelites - The AKFM System Continuous and Discontinuous Reactions	Spear. Chapter 10.
22	Metamorphic Petrology 5 - Metamorphism of Mafic Rocks, Metamorphism	Spear. Chapter 11.
23	Greenschists, Blueschists and Eclogites
24	Metamorphic Petrology 6 - Metamorphism of Calc-silicates	Spear. Chapter 12.