Geology 204

Dr. Alice L. Hoersch

Spring, 2001

Peale House



Hours by Appointment and Drop-in (if available)

Course Objectives

This course is designed to prepare students for the study of rocks in thin section (i.e. petrography). Topics to be covered include the elementary principles of crystal optics, familiarization with the microscope, the immersion method, isotropic, uniaxial, and biaxial optics, and the study of minerals in thin section. By the end of the course students should be able to readily identify the major rock-forming minerals in thin section. In addition students will learn how to find the necessary information to identify an unknown and perhaps never studied mineral. In order to accomplish the first two objectives, students will learn about the underlying concepts related to mineral behavior in transmitted/polarized light and the use of the petrographic microscope. This course is a standard requirement for geology, environmental science, and earth science/education majors. It is a helpful prerequisite for the study of petrology and crystal chemistry.

Outline of Topics to be Covered

Essentially the course will follow the table of contents given in Introduction to Optical Mineralogy by William D. Nesse. Readings will be assigned as the course progresses. Readings from time to time will be supplemented by handouts, journal articles, and other books, particularly near the end of the course when mineral groups and associations, as well as environmental mineralogy, will be discussed.

Besides Nesse, the other book highly recommended for the course is A Color Atlas of Rocks and Minerals in Thin Section by MacKenzie and Adams. This book will be useful for succeeding courses. I highly recommend that neither book be sold at the end of the semester.

Academic Prerequisites

(except with special permission)


Procedure of course

Seminar/Lectures: Tuesdays and Thursdays 9:30-10:45 A.M.

Lab: 2:00 5:00 P.M., Tuesdays

Labs and other assignments will be marked down five points for each late day. No labs will be accepted more than a week late. Students will be expected to devote outside time to labwork.

Attendance Policy

The policy of the University will be followed in this course. See the current University Bulletin for details. One caution: Over the years I have observed that, in general, grades can be correlated with absences. Greater numbers of absences mean lower grades.

Grading Procedure

Labwork, problem sets, written assignments 40%

portfolio 10%

quizzes 30%

lab final 5%

final 15%

Quizzes will consist of both short ones (10 minutes) based on assigned readings and fifty minute quizzes on larger topics.

The lab final will consist of identifying minerals and properties of minerals in thin section. The final will be comprehensive, but concentrate mainly on biaxial minerals, mineral groups, and mineral associations.

The +/- system will be used in this course. Under this system, the following grades can be assigned: A, A-,B+,B,B-,C+,C,C-,D+,D, and F.

Required Textbook

Nesse, William D. (1991) Introduction to Optical Mineralogy, 2nd Edition: New York,

Oxford University Press, 335 p.

Recommended Reference Book

MacKenzie, W.S. and Adams., A.E. (1994) A Color Atlas of Rocks and Minerals in Thin

Section: New York, John Wiley & Sons, Inc., 192 p.

Other Useful References


Bloss, F.D. (1961) An Introduction to the Methods of Optical Crystallography: New

York, Holt, Rinehart and Winston, 294 p.

Ehlers, E.G. (1987) Optical Mineralogy: Theory and Techniques: Palo Atlo, CA,

Blackwell Scientific Publications, 158 p. Kerr, P.F. (1977) Optical Mineralogy: New York, McGraw-Hill Book Co., 492 p.

Phillips, W.R. (1971) Mineral Optics: San Francisco, W.H. Freeman and Co, 249 p.

Stoiber, R.E. and Morse, S.A. (1994) Crystal Identification with the Polarizing

Microscope: New York, Chapman and Hall, 358 p.

Walhstrom, E.E. (1979) Optical Crystallography: New York, John Wiley and Sons,

488 p.


Deer, W.A., Howie, R.A. and Zussman, J. (1970) An Introduction to the Rock-Forming

Minerals: London, Longman Group Ltd., 528 p.

Ehlers, E.G. (1987) Optical Mineralogy: Vol 2, Mineral Descriptions: Palo Atlo, CA,

Blackwell Scientific Publications, 286 p.

Heinrich, W.E. (1965) Microscopic Identification of Minerals: New York, McGraw-Hill Book Co, 414 p.

Jones, N.W. and Bloss, F.D. (1980) Laboratory Manual for Optical Mineralogy:

Minneapolis, Burgess Publishing Co.

MacKenzie, W.S. (1980) Atlas of Rock-Forming Minerals in Thin Sections: New York,

John Wiley and Sons, 98 p.

Phillips, W.R. and Griffen, D.T. (1981) Optical Mineralogy: The Nonopaque Minerals:

San Francisco, W. H. Freeman and Co., 677 p.

Philpotts, A.R. (1989) Petrography of Igneous and Metamorphic Rocks: Englewood

Cliffs, NJ, Prentice Hall, 178 p.

Safferson, E.P. (1975) Identification Tables for Minerals in Thin Sections: London,

Longman Group Ltd., 378 p.

Spry, A. (1969) Metamorphic Textures: Oxford, Pegamon Press, 50 p.

Williams, H., Turner, F.J. and Gilbert, C.M. (1982) Petrography: An Introduction to the

Study of Rocks in Thin Sections, 2nd Edition: San Francisco, W.H. Freeman and

Co., 626 p.

Yardley, B.W.D., MacKenzie,W.S. and Guilford, C. (1990) Atlas of Metamorphic Rocks

and Their Textures: New York, Longman Scientific and Technical, 120 p.