Soils Clays and Weathering (Geology 4001/6001)

     Georgia State University

      Department of Geology

      Fall Semester 2002

 

Instructor: Dr. W. Crawford Elliott, Associate Professor

Office: 331 Kell Hall    Office Phone: (404) 463-9548   E-mail: wcelliott@gsu.edu

Primary Texts: X-ray Diffraction and the Identification and Analysis of Clay Minerals, by D.M. Moore and Robert C. Reynolds, Jr. (2nd Edition), 1997, Oxford University Press; and Soils and Geomorphology, by P.W. Birkeland, Oxford University Press, 1999, 430 p.  Office Hours:  M, W, 9 – 10 am

Lectures: M, W, F 10:00 - 10:50 Lab: W, 1:15 – 4:05 pm.

 

Objectives: The primary objective of this course is to introduce clay minerals in terms of their atomic structures, chemical compositions, presence in soils and rocks, and their pragmatic uses. This course stresses understanding clay mineralogy, soils and weathering from a petrogenetic standpoint.  This course is also intended to present the base information needed by students who wish to pursue advanced courses in X-ray diffraction and crystallography, weathering, soils, and clay mineralogy.  In terms of laboratory exercises, the primary objective will be to provide experience in the separation of clay minerals from rocks/soils/saprolites and their identification using X-ray diffraction. 

 

Mechanism: This is a lecture and lab based course.  The lectures are intended to introduce various topics relevant to clays, soils and weathering.  The students will find it very helpful to attend lecture and comprehend the material presented in lecture.  Most of the lecture topics will be covered in Moore and Reynolds (M&R) and Birkeland (B). Five articles/papers (Reserve Readings) will be read in this course.  Reserve Readings and will be kept in two binders in 314 Kell.   For laboratory, concepts of X-ray diffraction, and the use of X-ray diffraction for mineral identification will be stressed. I will require attendance at laboratory sessions in which X-ray safety training uses of X-ray diffraction and clay laboratory procedures are taught, and when data are being discussed (See Schedule).  Two all-day field trips are planned (See Laboratory Schedule).   There are three prerequisites for this course: Geol 1211; Geol 3002; Chemistry 1212. If in my opinion, a student has missed too many laboratory or lectures, then the instructor reserves the right to withdraw the student from this course at any time.

 

Grading: The grade will be a weighted average of two one-hour exams, final exam, paper, and laboratory grades.  Each exam counts 20% of the final grade, the final exam is cumulative and counts 25% toward the final grade. The laboratory will count 20% of the final grade. There will be one paper written on a clay mineral/weathering/soil topic of choice, and the grade of the paper will comprise 15% of the final grade. GEOL 6001 students will present their papers in the last week of the course. Students will be working in teams on the separation and identification of the clay minerals.  Each team will submit a separate report of data gathered as a group.  Each student is responsible for the data and understanding the contents of his report.  The Laboratory Grade is calculated from the scores earned from: Lab Quiz (50%), Identification #1 (25%), and Identification (#2).

 

Repeated absences from lecture or failure to perform the laboratory analyses in a timely manner will result in a reduction of final grade or administrative withdrawal from the course.   Do not miss the exams or required laboratory sessions.  If you have a valid reason for missing an exam or required laboratory exercise, please see me as soon as possible to reschedule the exam and/or lab exercise.  If I do not hear from the student in a reasonable period of time (3 days) from the time of the exam or due date of the exercise, then a zero will be awarded for that exam or exercise.  Graduating students should be aware of the possibility of being required to take an early Final Exam.

 

Safety: All students will be performing analyses using the X-ray Diffractometer (XRD) housed in the Geology Department at GSU.  The procedures for operating this XRD will be adhered rigorously.  Serious deviations from these procedures or failure to attend the required safety training sessions will be grounds for immediate withdrawal from this course. Students must attend the GSU Radiation Safety Course and XRD Site Training before using the XRD. See Laboratory Schedule for the time and date of the training and radiation safety sessions. Safety glasses are required for all laboratory work including XRD analyses.  Prescription glasses satisfy this requirement.

 

 

Available Reference Books.

 

 

The Books listed below can be found in the Clay Laboratory (Kell 310).  They remain there for all to use.  These books were purchased as reference texts for the study of clay minerals, separations techniques and soils and they are not to be removed from Kell 310.

 

Cullity, B.D.,1978,  Elements of X-ray Diffraction. [Second Edition]. Addison and Wesley, 555p.

 

Minerals in the Soil Environment, Second Edition. [eds. J.B. Dixon, and S.B. Weed], 1989, Soil Science Society of America Series 1., 1244 p.

 

Jackson, M.L., 1979, Soil Chemical Analysis.  M.L. Jackson, Madison, WI., 897 p.

 

Moore, D.M., and Reynolds, R.C., 1997,  X-ray Diffraction and the Identification and Analysis of Clay Minerals. (2nd Edition), Oxford University Press, 378 p.

 

 

Structure Models.

 

Structure models (ball and stick) of clay minerals (kaolinite, chlorite, illite, biotite, and smectite) are also kept in Room 310 Kell for examination and reference. These models show tetrahedral and octahedral sheets, layers and assembly of sheets forming common clay minerals.  These models were purchased for reference and study for this course and other Geology Department courses discussing clay minerals.  They must remain in Kell 310 or Kell 314.

 

 Course Schedule

This is a general plan for this course.  Deviations may be necessary.

 

Date                Topics                                                                         Reading

 

8/19                  Course Introduction.

8/21                  Clay Minerals in the Rock Record.                                             M&R p.  14-26.

8/23                  Clay Minerals in the Rock Record.                                             M&R p.  14-26.

 

8/26                  Structure and Properties of Clay Minerals.                                  M&R p. 104-129.

8/28                  Structure and Properties of Clay Minerals.                                  M&R p. 104-129.

8/30                 Structure and Properties of Clay Minerals.                                  M&R p. 104-129.

 

9/2                    Labor Day Holiday.

9/4                    Clay Mineral Chemistry, and Classification.                                 M&R p. 138-168.

9/6                    Clay Mineral Chemistry, and Classification.                                 M&R p. 138-168.

 

 

 

Course Schedule (Continued)

Date                Topics                                                                                     Reading

 

9/9                    Clay Mineral Chemistry, and Classification.                                 M&R p. 138-168.

9/11                  Clay Mineral Chemistry, and Classification.                                 M&R p. 138-168.

9/13                  Interstratification, Illite/smectite.                                     M&R p. 169-182.

 

9/16                  Interstratification, Illite/smectite, Gulf Coast                                M&R p. 169-182

9/18                  Geothermometry                                                                       RR #1.

9/20                  Origin of Clays.                                                                         M&R  p. 186-190.

 

9/23                  Structural Formulae, Layer Charge                                             M&R p. 190-192.

9/25                  Formulae and Layer Charge.

9/27                  Clay-Organic Interactions (Governing Principles).                       M&R p. 128-129.         

 

9/30                 Review (lecture) Test #1 (lab period)

10/2                  Soils Characteristics, profiles.                                                     B  p. 1-24.

10/4                  Soils Characteristics, profiles.                                                     B  p. 1-24.

 

10/7                  Paleosols.                                                                                 B  p. 24-28.

10/9                  Soil Classification                                                                      B  p. 29-52 (Scan).

10/11                Soil Classification                                                                      B  p. 29-52 (Scan).

 

10/14                Physical Weathering.                                                                 B p. 53-59.

10/16                Physical Weathering                                                                  B p. 53-59.

10/18                Chemical Weathering                                                                B p. 59-84.                                           

10/21                Chemical Weathering                                                                B p. 59-84        

10/23                Chemical Weathering                                                                B p. 59-84.

10/25                Products of Weathering                                                             B p. 85-104.

 

10/28                Products of Weathering                                                             B p. 85-104.

10/30                Soil Formation Processes                                                           RR #2

11/1                  Soil Formation Processes                                                           RR #2             

 

11/4                  Soil Formation Processes                                                           RR #2.

11/6                  Factors of Soil Formation                                                           B   p. 141-147.

11/8                  Jenny’s Equation                                                                       B   p. 141-147.

 

11/11               Review (Lecture) Test #2 (l;ab)

11/13                Effect of Parent Material on Soils                                               B  p.  148-170.

11/15                Effect of Parent Material on Soils                                               B  p.  148-170.

 

11/18                Weathering and Soil Development through time                           B  p.   171-178

11/20                Weathering and Soil Development through time                           B  p.   215-226.

11/22                Bentonites (Glass to Clay Reactions)                                          RR # 3

 

11/25                Bentonites and K-bentonites                                                       Notes

12/2                  Kaolin Deposits                                                                         RR # 4

12/4                  Toxic metals in Soils                                                                  RR # 5

12/6                  Last Class (Review)

12/9                  Final Exam. (10:15 am – 12:15pm, Room 314 Kell)

Laboratory Schedule

 

Date                                        Topic                                                   Readings

 

8/21      Orientation, Why X-ray Generation and Diffraction?        M&R p. 1-13 (scan), p. 28 - 40.

 

8/28      Attend X-ray Safety Course (Kell 314).                          M. Belanger (GSU R.S.O.)

            Diffraction, Scattering, Bragg’s Law.                             M&R  p. 61 - 71.

 

9/4        Diffraction, Scattering, Bragg’s Law, Diffraction Demo.              M&R p. 61 - 71.

            Site training on Department X-ray Diffractometer (XRD).           M&R p. 42 - 59.          

            Assign unknown to each group, random mount prep.                    M&R p. 220 - 222.                                                                   

9/11      Practice running samples on XRD, Analysis of Unknown.            M&R p. 42 - 59.

            Identify Unknown (Handout).

 

9/18      Field Trip, Piedmont Soil, Coweta County. Report of unkown due

 

9/25      Test #1 (Lecture), Present Unknowns to Class after exam.                    

 

10/2      Sand/silt separations.                                                                 Jackson (p. 123-124).

 

10/5      Field Trip #1 (Saprolites or K-bentonites).          

 

10/9      Clay separation and preparation of slides for XRD                       Jackson (p. 127-139)

(Via centrifugation or timed settling.)                              M&R p. 204-208.

 

10/16    X-ray Diffraction analysis of clay fraction (air dry,                      M&R p. 227 - 243.

Glycol, and heated samples.)

 

10/23    X-ray Diffraction analysis of clay fraction (air dry,                      M&R p. 227 - 243.

Glycol and heated samples.)      

 

10/30    Saprolite petrography, SEM demonstration, Dr. Robert Simmons, Department of Biology.

 

11/6      Test #2 (Lecture), Present results of clay fraction to class.  Report of clay fractions due.

 

11/9      Field Trip (Kaolin Deposits).

 

11/13    Review Laboratory, Catch up.

 

11/20    Lab Quiz

 

Important Dates

 

September 25                        Test #1  (Lab Period)

October 5                               Field Trip #1

October 11                             Withdrawal date and possibly receive a “W”.

November 6                           Test # 2   (Lab Period)

November 11                         Field Trip #2

December 1                           Paper  Due.

November 20                         Laboratory Exam

December 6                           Last Class

December 9                           Final Exam. (10:15 am, Room 314 Kell)