EMENDED Nov. 12, 2012 Soils Clays and Weathering (Geosciences 8001) Georgia State University Department of Geosciences Fall Semester 2012 Instructor: Dr. W. Crawford Elliott, Associate Professor, Department Chair Office: 331 Kell Hall Office Phone: (404) 413-5756 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. Office Hours: 4-5 pm M, anytime the door is open, or by appointment. Lectures: M, W, 5:30pm 7:10 pm, Kell 314. Laboratory: By arrangement, see below. Objectives: The primary objective of this course is to be able to describe and to understand the formation of clay minerals in rocks and soils through studies of their atomic structures, chemical compositions, and identifications using X-ray diffraction. Consequently, this course stresses understanding clay mineralogy, soils and weathering from a petrogenetic standpoint. A secondary objective is to appreciate and know the pragmatic uses of clay minerals in our lives. This course is also intended to present the base information needed by students who wish to pursue advanced graduate 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 identification of clay minerals from rocks/soils/saprolites using X-ray diffraction. Other exercises are planned and we will attempt to cover these topics (petrography of soils and clays). 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). Background and course material for soils and weathering will be via class notes and selected readings to be distributed. In addition, up to four articles/papers (Reserve Readings, RR) will be read in this course and structured discussions of these papers will take place during lecture (See Schedule). Reserve Readings and will be kept in one binder 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 lectures presenting the X-ray safety training and uses of X-ray diffraction (See Schedule). One all-day field trip is planned (See Schedule). There are three prerequisites for this course: Geol 1211; Geol 3002; Chemistry 1212. If in my opinion, a student has missed too many (too many corresponds to N>3) lectures, is late too many times or leaves early too many times (again too many corresponds to N>3), then the instructor reserves the right to reduce the final grade and/or withdraw a student from the course. Course evaluations are solely solicited on-line (www.gosolar.gsu.edu) at a specified period of time at the end of the course. All students are responsible for reading e-mail at your GSU address. Regulations specified in the current GSU Graduate Catalog apply to this course. These regulations include those pertaining to academic honesty and student conduct. Graduate students at GSU auditing this course will be required to attend lectures, be an active participant in the course, and present one lecture or lead one discussion on a reserve reading to be determined by the instructor to be awarded an audit grade. Grading: The grade will be a composite score based on the score of the Test #1, Final exam, paper, and laboratory grade as follows. The Test 1 and Final Exam together count 50% of the final grade. The laboratory will count 25% 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 25% of the final grade.
The paper is graded equally on the following components (content, organization, correct reference techniques and oral presentation). Depending on the number of students enrolled in this section, the students will present their papers in the last week of the course. The Laboratory Grade is calculated from the scores earned from: Lab Quiz and attendance of the X-radiation safety course. Repeated absences (n>5) from lecture or failure to perform the laboratory analyses in a timely manner will result in a reduction of final grade and/or administrative withdrawal from the course. Plagiarism will result in a lowered grade on the assignment and the student will be reported to the University Administration if circumstances warrant it. 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 or due date for 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. Safety: All students will be performing analyses using one of the two X-ray Diffractometers (XRD) housed in the Geosciences Department at GSU. The procedures for operating this XRD will be adhered rigorously. Serious deviations from these procedures at any time in the semester or failure to attend the required safety training sessions are grounds for immediate withdrawal from this course. Students must register and complete the GSU Radiation Safety Course and XRD Site Training before using the XRD. The GSU training request form can be read at: http://www.gsu.edu/images/vp_research/environmentalprogramstrainingform.pdf. Safety glasses are required for all laboratory work. Prescription glasses satisfy this requirement. Available Reference Books. The Books listed below can be found in the Clay Laboratory (Kell 310), my office (331 KH) or in the X- ray diffraction lab (KH 380). They remain in one of those three places 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 Hall. 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 or Kell 331 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 331. October 3 Test 1 Important Dates
October 9 Withdrawal date and possibly receive a W November 5 Field Trip (Kaolin District) November 14 Test 2 November 12-16 Laboratory Procedures Exam Period November 28 Paper Due. December 3 Last Class December 10 Final Exam, 4:15 pm (Same room as lecture). Course Schedule This is a general plan for this course. Deviations may be necessary. Week Date Monday Readings Wednesday Readings 1 8/20-8/22 Course Introduction. M&R: 1-14. Clays in the Rock Record. M&R: 14-26. Why Clays? Why X-rays? 2 8/27-8/29 Generation of X-rays M&R: 28-44. GSU X-ray M&R: 44-60. Diffractometer 3 9/5 9/14 Elementary Diffraction M&R: 61-72. Bragg s Law M&R: 61-72. 4 9/17 9/19 Structures of Clay Minerals. M&R: 104-129. Structures of Clay Minerals. M&R: 104 129. 5 9/24 9/26 Clay Mineral Chemistry and Classification. M&R p. 138-168. Clay Mineral Chemistry, and Classification. M&R p. 138-168. 6 10/1-10/3 Structural Formulae, Layer M&R p. 169- Test 1 (8/20-9/26) Charge. 182. 7 10/7-10/9 Interstratification, M&R p. 182- Application to Oil and RR #1. Illite/smectite. 192. Gas Exploration. 8 10/14 Clay-Organic Interactions M&R p. 128- Soil Dynamics and RR#2 10/16 (Governing Principles). 129. Introductory Remarks 9 10/21-10/23 Physical Weathering RR#3 Soil Genesis RR#3 10 10/28-10/30 Soil Structure RR#4 Surfaces and Acidity RR#5 11 11/5 11/7 Soil acidity/chemistry RR#5 Soil Chemistry (notes) 12 11/12 11/14 Kaolin Deposits RR # 6 Kaolin Deposits. X-ray identification 13 11/26 Soil Classification/Orders Notes Soil Contamination RR#7 11/28 14 12/3 Catch up, questions, answers. 15 12/10 Final Exam (16:15-18:45) RR#1: Pevear, D., 1999, Illite and Hydrocarbon Exploration, PNAS, v. 96, p. 3440-3446. RR#2: Brady and Weil, Nature and Properties of Soils (Chapter 1, p. 1-28) RR#3: Brady and Weil, Nature and Properties of Soils (Chapter 1, p. 29-70) RR#4: Ashman and Puri, Essential Soil Science, Chapter 2 (p. 27-45) RR#5: Ashman and Puri, Essential Soil Science, Chapter 3 (p. 46-66) RR#6: Hurst and Pickering: Clays and Clay Minerals v. 45, p. 274-285. RR#7: Miller and Gardiner: Soils in Our Environment (Chapter 17, p. 499-529).
Laboratory Assignments The laboratory assignments are described in detail in a separate handout. They are listed below for convenience. Assignments 2-5 are done in teams composed of no more than 2 students. 1) Register and completer GSU Radiation Safety Training on line, waived if already an active user. 2) X-ray Diffraction analysis of an unknown clay fraction (preparation of clay fraction, oriented slide airdry, Glycol, and heated samples for XRD analyses). M&R p. 227 243, due October 30 (10 hours). 3) Take laboratory quiz on GSU XRD, Radiation Safety, Diffraction, GSU Diffractometer, and Generation of X-rays. (5 hours including 4 hours review) between November 15 and November 20. Laboratory Assignments. #1. GSU Radiation Safety Training. All students and faculty using the X-radiation machines such as the GSU X-ray diffractometer must complete the Radiation Safety Course given by the GSU Radiation Safety Officer. The session can be completed on-line and lasts approximately 1.5 hours long and one lecture session will be devoted to Radiation Safety. Users of certain machines employing X-rays are exempt from this training requirement (i.e. Sedigraph). If a dose record form is required then the students must complete this form. This decision should be made in the next week or so from the start of the term. #2. Identification of a clay mineral. An argillaceous rock will be given to each student (or student will submit a sample for analysis). The < 2 micron size will be obtained and the student will prepare three slides of an oriented mount of the clay fraction for analysis following methods in Jackson (1979). The choice of the sample will be done in collaboration with the instructor. Each team must analyze a slide treated by solvation with ethylene glycol vapor, heat-treatment (550 o C) for one hour, and in as received state. The range of scan is 2-32 o 2 (1 minute/ o 2, Cu radiation). The 00l reflections will be visible (no hkl will be present). You will assign Miller Index to each diffraction peak, calculate d-spacing, and change of d-spacing resulting from treatments. Moore and Reynolds and class notes may be consulted to identify the minerals based on the d-spacing measured and their changes due to treatments. As above, you may do this as a team and submit a team report. All team members must be responsible for all statements in the report. Your report must include the following items: diffraction scans, determination of all d-spacings, identification of clay minerals and rationale for identification, and a brief statement about the clay mineral base on a summary of information from Moore and Reynolds or other readily available material (Crystal class, phyllosilicate structure, presence in rock record (how formed), economic uses, and chemical composition. #3 Lab Quiz. Following completion of the six exercises above, a one-hour lab quiz will be given at a time convenient for both student and instructor to gauge the students understanding of the following concepts: diffraction, GSU diffractometer geometry and method of analysis, se of Bragg s law, X-ray generation, and Radiation Safety. If you have done your work conscientiously, then this exam should not be difficult. This exam must be completed between November 15 and November 20. A 15% penalty for late submission applies. Students are on-their-honor and they must not discuss the exam with anyone except the instructor. This laboratory will not serve as a proxy to help satisfy requirements for GEOL 6420 (Analytical Methods) during this current semester or any future semester. Final Draft: September 3, 2012. Emended: November 12, 2012.