Geology 321
Igneous and Metamorphic Petrology
Spring, 2004
Description of the Course
Instructor: Sheila Seaman, Morrill 242, phone 545-2822, e-mail: sjs@geo.umass.edu; office hours: Weds 2-4, Fri 8-10 and by appointment
Textbook:
Winter, John D., An Introduction to Igneous and Metamorphic Petrology
About the course:
This is a course in petrology, which means "the study of rocks". In this course, we study the origin of igneous and metamorphic rocks. This includes the origin of most of the Earth. Every igneous and metamorphic rock is a product of the plate tectonic lifestyle that this planet has apparently led since its differentiation. Every igneous and metamorphic rock holds information about some segment of the Earth's history. Our purpose in this class is to learn to "read" igneous and metamorphic rocks to find out what suites of rocks from different parts of the world tell us about the Earth's long and complex history, about what is going on now in the depths of the Earth, and about how the solid Earth system interacts with the atmosphere, hydrosphere, and biosphere.
Administrative details:
Attendance: Developing an understanding of petrology critically depends on logically building a chain of concepts. Missing a class can ruin your understanding of a big chunk of the course. Perfect attendance in this course is mandatory. Only excused absences (those cleared with me ahead of time for extreme circumstances) will be tolerated. One or more unexcused absences will inevitably result in a drop in your final grade. Arriving late or leaving early are likewise unacceptable.
Exams: There will be two midterm exams and one final exam in the course.
Quizzes: There will be a short quiz in class on some Mondays. It will cover material presented in class the previous week. There will be no make ups except in the case of excused absences.
Homework Problems: Homework problems will occasionally be assigned. They will be due one week after they are assigned. Work handed in late will lose one point per day late, on the basis of ten total points. You must complete all assignments in order to pass this course.
Labs: Lab write-ups will be due one week after the lab meeting. Lab write-ups, like homework problems, will lose one point per day that they are handed in after they are due.
Class Notes: The key to success in this course, and in all courses, is taking good notes. Keep your class notes in a ring binder, interleaved with the handouts that refer to the notes of that particular day. Your class notes will be collected twice in the course of the semester and will be graded. They will be collected on March 3 and on May 3.
Independent Research Project: Each person in the course will choose a rock to study during the course of the semester. A portion of several lab periods will be devoted to instruction on techniques that you will use to study your rock. A detailed description of the scope of the research project will be provided early in the course.
Basis for Grading: A Summary*
Three exams: 36%
Labs: 15%
Quality of Notes 14%
Quizzes and Homework: 15%
Research Project: 20%
* Unexcused absence will result in lowering of final letter grade
Field Trips: There will be two field trips in the course. One of these will take place during an extended lab period, and the other will be a weekend trip. The first will focus on metamorphic rocks of Massachusetts. The second will be a weekend camping trip. We will go to coastal Maine, leaving in the mid-afternoon on Friday, May 7, and returning in the evening on Sunday, May 9. One of the two full days will be devoted to examining volcanic strata on Great Cranberry Island, and the other day to examining intrusive rocks on Mount Desert Island. Both fields trips, like all class meetings and labs, are non-optional, and missing the weekend field trip to Maine will without doubt affect your grade.
MOST IMPORTANTLY!! Please ask questions in class whenever something
doesn't make sense. Without doubt, if you don't understand something, you will
not be alone! Somebody has to ask for clarification...please feel at ease
being the person who does so! Also, please set up a time to go over material
with me that has you confused. Keep looking at your notes...I realize that you
have a heavy class load, but try not to let a week of not quite understanding
the material pass. Deal with confusion early!
Syllabus
All readings are from An Introduction to Igneous and Metamorphic Petrology, by John D. Winter.
Reading Topic
I. Igneous Petrology
Jan. 28 Introductory slide show: igneous and metamorphic processes: how the Earth works
Chapter 1 30 The Earth’s interior, conditions inside the Earth
Feb. 2 Temperature and pressure gradients
Chapter 10 4 Why does the Earth melt?
6 How does the Earth melt?
Chapter 6 9 How the Earth melts–continued
11 How does magma move?
13 The freezing of magma to make solid rock
18 Phase diagrams: charting the crystallization of magma
Chapter 7 20 The phase rule and interpreting phase diagrams
23 Ternary phase diagrams: the crystallization of ocean floor basalt
25 Ternary phase diagrams continued
27 Effects of H20 and CO2 on melting of rocks, on crystallization, and on explosivity of magma
March 1 FIRST MIDTERM EXAM
Chapter 8 3 Petrogenetic modeling: using major elements to understand how magmas crystallize
5
Chapter 9 8 Petrogenetic modeling: using trace elements to understand how magmas crystallize
10
12 Petrogenetic modeling: isotopes as tools for understanding interactions between lithosphere, hydrosphere, biosphere, and atmosphere
Chapter 10 15 Petrology and plate tectonics: How does Earth produce ocean crust?
17
Chapter 13 19 Volcanism in island arcs: explosive volcanism and the growth of continents
Chapter 16 29
31 Why does Earth have continents?
Chapter 18 April 2 SECOND MIDTERM EXAM
Metamorphic Petrology
Chapter 21 5 Metamorphic petrology: what is metamorphism and how does it happen?
7 Conditions during mountain-building: temperature, pressure, fluids
Chapter 24 9 Equilibrium in metamorphic rocks
12 Metamorphic phase diagrams: depictions of conditions during mountain-building
Chapter 25 14 The concept of metamorphic facies and global tectonics
Chapter 26 16 Metamorphic reactions: how mineral assemblages change without the occurrence of melting
Chapter 28 21 Metamorphism of clay-rich sediments at plate margins
22 Metamorphism of clay-rich sediments at plate margins
23 Metamorphism of clay-rich sediments at plate margins
Chapter 25 26 Metamorphism of ocean floor at plate margins
28 Metamorphism of ocean floor at plate margins
Chapter 29 30 Metamorphism of carbonate banks at plate margins
May 3 Metamorphism of carbonate banks at plate margins
Chapter 27 5 Pressure-temperature-time paths: understanding the life cycles of mountain belts
7 Geothermometry and Geobarometry
May 7-9: Field trip: Coastal Maine
10 The role of water in producing igneous and metamorphic rocks
12 The petrologic development of mountain belts
Lab Schedule
Week of
Feb 2 Mineralogy and textures of igneous rocks in hand specimen
Feb 9 Igneous minerals and textures in thin section
Feb 16 Layered mafic intrusions as illustrations of crystallization and differentiation
Feb 23 Use of rock saws; thin section making
Mar 1 Basalts: at spreading centers, at hot spots, and within continents
Mar 8 Andesites, rhyolites, and granites: the construction of continents
Mar 15 Geochemical calculations
Mar 29 Geochemical modeling
Apr 5 Metamorphic minerals and textures in thin section and hand specimen
Apr 12 Metamorphism of shoreline clay-rich sediments: Pelitic metamorphic rocks
Apr 19 Field trip: Western Massachusetts metamorphic rocks
Apr 26 Metamorphism of ocean floor: Metabasalts
May 3 Metamorphism of carbonate banks: Calcareous and calc-silicate rocks
May 10 Presentation of research projects