GSC 325/GSC 325L (Course #12291/12292):

Optical Mineralogy / Optical Mineralogy Laboratory

Course Outline—Winter, 2006

 

Dr. Jonathan A. Nourse                        Office Hours: Monday and Wednesday: nooon-1:30PM

Office:  Building 8, Room 242C                                    Tuesday and Thursday: noon-1PM

Telephone:  (909) 869-3460                                         (or make special appointment)

Email: janourse@csupomona.edu

 

Objectives

To provide a thorough basis in the theory and practical petrographic analysis of light interaction with non-opaque minerals.  The first half of this course focuses on the description, chemical composition, and crystallography of the common rock-forming minerals according to their optical properties as determined with the petrographic microscope. The second half of the course provides students practical experience with determining mineral composition, texture, and origin of various igneous, sedimentary, and metamorphic rocks as viewed in thin section.  The field trip will offer students an opportunity to collect rock samples from which they will cut personal thin sections.

 

Lecture and Laboratory        Meet back-to-back Tuesdays and Thursdays from 1:00-4:50PM in Room 8-239 or 8-237.  Typically we will begin with ~ 1-2 hours of instruction, then take a break. Students shall utilize remaining time to complete laboratory exercises.  Laboratory work will usually be due one week after date of assignment.  A substantial penalty will be assessed for late submissions.  Please use laboratory report format specified on separate handout.

 

Required Text            Nesse, William D., 2004, Introduction to Optical Mineralogy (3rd edition), Oxford University Press, Inc., 335p.  (The 1990 2nd Edition is acceptable if you can obtain one)

           

Supplemental Readings

A variety of useful textbooks and practical reference manuals are provided in the laboratory.

 

Prerequisites

GSC 215/215L

 

Evaluation

Because the lecture and laboratory components are intimately interrelated, scores on exams, and laboratory/ field exercises will be combined to determine a total course grade worth 4 units.  Note that this course is heavily weighted toward laboratory work.

Grades will be calculated as follows:

                        Lecture Midterm                                   15%

                        Laboratory Midterm                             15%

                        Lecture Final                                        15%

                        Laboratory Final                                   15%

                        Laboratory Exercises                            40%

 

Tentative Schedule of Lectures and Laboratory

(Sequential Reading Assignments To Be Integrated With Topics)

Week 1 (January 3 and 5)

Course Logistics; Preview of the information available from petrographic analysis of thin sections; Optical mineral groups; Properties of light; Snell’s law of refraction; Index of refraction; The petrographic microscope and its working parts; Relief and index of refraction; Extinction and orientation; Retardation and birefringence

 

Week 2 (January 10 and 12)

Double refraction and polarization (the calcite experiment); Immersion media methods applied to identification of isotropic, uniaxial, and biaxial minerals; The Becke line method; Sign of elongation (length-slow vs. length fast); Pleochroism; The isometric index indicatrix

                                               

Week 3 (January 17 and 19)

Optical properties of isotropic and uniaxial minerals; The uniaxial index indicatrix;

Uniaxial interference figures; Uniaxial positive vs. uniaxial negative

                       

Week 4 (January 24 and 26)

Optical properties of biaxial minerals; Biaxial index inicatrices: acute bisectrix indicatrix vs. obtuse bisectrix indicatrix;  Biaxial interference figures; Determination of optic sign and 2V

 

Week 5 (January 31 and February 2)

Optical properties of the common rock-forming minerals: Quartz, alkali feldspars, plagioclase feldspars, pyroxenes, amphiboles, micas; Determination of An content in plagioclase. 

Field Trip—Tuesday, January 31, Noon-5:00 PM

 

Week 6 (February 7 and 9)

**LABORATORY MIDTERM (Allow 6 hours)--Tuesday PM, February 7 and

Thursday PM, February 9 (if necessary)

** LECTURE MIDTERM (Allow 2 hours)--Thursday, February 9, 1 PM

 

Week 7 (February 14 and 16)

Petrography and classification of volcanic rocks as viewed in thin section; Methods of thin-section preparation

 

Week 8 (February 21 and 23)

Petrography and classification of plutonic rocks as viewed in thin section

 

Week 9 (February 28 and March 2)

Petrography and classification of sedimentary rocks as viewed in thin section

 

Week 10 (March 7 and 9)

Petrography and classification of metamorphic rocks as viewed in thin section

 

Week 11 (March 13-16)—Finals Week

**LABORATORY FINAL: Allow six hours—time to be arranged

**LECTURE FINAL: Allow two hours---time to be arranged