GSC 444 /444L Geotectonics / Geotectonics Laboratory
EXPANDED COURSE OUTLINE
I. Catalog Description
GSC 444: Study of the major tectonic elements of the Earth, their geometry, kinematics and dynamics with special emphasis on the Cordillera of western North America. All of the tectonic features will be analyzed in the context of plate tectonics. 3 units lecture..
GSC 444L: Group study of selected topics related to tectonics. Instruction is carried out in the field and laboratory. 1 unit.
II. Prerequisites
GSC 219/219L, GSC 333/333L
III. Objectives
To provide an overview of Earth's tectonic activity as manifested by modern-day plate interactions and ancient deformational features preserved in the rock record. The first three weeks will examine essential features of modern tectonic environments. The remaining two thirds of the lecture sequence will outline the Precambrian to Recent tectonic evolution of North America, emphasizing events preserved in the southern Cordillera. Laboratory and field work will explore accessible examples of specific tectonic features described in lecture. Two half-day field exercises and two weekend field trips will be taken to study field evidence for multiple deformation and intrusion. One or two laboratory exercises will focus on petrographic description of strained rocks.
IV. Method of instruction
Standard lecture format, utilizing drawings and overhead transparancies to convey three dimensional concepts. Students will be expected to take notes and fill in details on copies of transparencies made available in a supplementary note package. Field work will require standard geological mapping gear. Students will participate in laboratory instruction as follows: Each student will serve as a resident expert for one site visited during a field trip. An oral presentation to the class and written report are required as part of this educational exercise.
V. Evaluation
Grades will be calculated as follows:
Midterm Exam 25%
Final Exam 30%
Laboratory and Field Exercises 20%
Field Trip Report:
Oral Presentation 10%
Written presentation 15%
*Note: GSC 444 and GSC 444L must be taken concurrently. Scores on exams, laboratory and field exercises, and field trip reports will be combined to calculate a total course grade worth 4 units.
*Passing letter grades will correspond approximately with these ranges:
100-90 (A); 89-80 (B); 79-70 (C); 69-60 (D)
A curve may be used to adjust these grades downward slightly, but no overall
course grade below 50% will be considered passing.
VI. Summary of Lectures and Laboratory Sequence
Recent Course Syllabus
GSC 444/444L: GEOTECTONICS
(WINTER, 2001)
REQUIRED TEXT: Keary, Philip and Vine, Frederick J., 1996, Global Tectonics (2nd Edition), Blackwell Science, Ltd., 333 p.
REQUIRED NOTES: (package of xeroxed articles, notes, and illustrations will be made available at cost (probably about $10-$15). Please begin reading the articles early in the quarter.
LECTURE: MWF, noon to 1PM, Room 4-A-608
LABORATORY: Scheduled for Friday 1-4 PM in 8-239. With the exception of 2-3 homework problems, laboratory will consist of field trips and related reports. Focus will be on rock identification, recognition of fabrics or structures, and determination of field sequence in rocks subjected to multiple deformation and igneous intrusion.
FIELD REQUIREMENT: Field trips will visit classic localities that display many of the tectonic features described in Part II of the lecture sequence. Student experts will be called upon to summarize controversial tectonic issues in front of outcrops or vistas selected by the instructor. Student participation is expected in two weekend field trips (February 23-25 and March 9-11), one Saturday trip (January 27), and one Friday afternoon trip and March 2).
RESEARCH REQUIREMENT: Choose a research topic from the list provided. Each student is required to: A. deliver a brief oral presentation on chosen topic at an appropriate time during one of the field trips, and B. write a short paper on some controversial aspect of the same topic. Specific details about format and expectations of these oral and written reports are provided separately.
EVALUATION: Student scores will be combined in the following proportions to determine one grade worth 4 units:
Midterm Exam 25%
Final Exam 30%
Homework and Laboratory Exercises 20%
Research Project: Oral Presentation 10%
Written Presentation 15%
**No makeup exams unless a documented emergency or prior consultation**
** Timely submittal of written assignments is expected of all students**
TENTATIVE CLASS SCHEDULE
Date Lecture Topic and Reading Assignments
Part I: Modern Global Tectonics (how we think it works today)
---Environments, Mechanics, Processes---
**This is the appropriate time to read most of your textbook**
January 3, 5 Course Logistics / Motivation / Introduction: Read Chapter 1, Chapter 11, p. 248-250, Chapter 2, p. 8-9, p. 15-34, p. 40-44, Chapter 4, Chapter 5
Famous hypotheses related to Earth dynamics; General geophysical constraints on Earth’s layers; Stress regimes in the lithosphere, resulting fault geometries; Physiography of plate boundaries, Inferred early record of heat loss and continental growth. When did “Plate Tectonics” begin?
January 5 (Friday) Laboratory #1 --Pangea Reconstructions
January 8, 10, 17, 19 Modern Day Plate Boundaries (geometric, structural, and geophysical characteristics; distinguishing lithologic assemblages)
Modern extensional tectonic environments—Read Chapters 6 and 10
Modern compressional tectonic environments—Read Chapters 8 and 9
Modern strike slip tectonic environments—Read Chapter 7
Driving mechanisms for plate tectonics—Read Chapter 11
**January 12 (Friday)--Lecture will not meet.
Start working on Lab #2: Divergent and Convergent Tectonic Environments
**January 15 (Monday) is an academic holiday**
Part II: The Historical Record---Tectonic Evolution
of North America with an Emphasis on the Southwestern Cordillera
January 22- Precambrian-Paleozoic Formation and Growth of the North
February 9 American Craton and Mobile belts:
(approximately) -Tectonic provinces of North America; Archean-Middle Proterozoic evolution and growth of the North American craton
-Mid Proterozoic-Early Paleozoic: Tectonic accretion in the
southwest and northeast succeeded by rifting of North America
-Development of dual miogeoclinal / shelf sequences along the eastern and western margins of North America
-Mid-Late Paleozoic: Development of Appalachian/ Ouachita mobile belts; the ancestral Rocky Mountains;
Early Cordilleran tectonics: Mid Paleozoic Antler orogeny; Late Paleozoic-Early Triassic Sonoma orogeny; Establishment of NNE tectonic trends
-The Permian truncation event and the Triassic arc
January 27 Saturday field trip to the San Gabriel Mountains
**February 5 (Monday)— Midterm Exam--Please Plan for Three Hours**
February 12- Mesozoic-Cenozoic Tectonic Evolution of the Southern
March 9 Cordillera:
(approximately) -Opening of the Atlantic; Middle Triassic-Jurassic continental margin magmatic arc; intra arc tectonic and metamorphic events
-The Mojave-Sonora Megashear(s): Late Jurassic truncation of the southwest continental margin and associated opening of the Gulf of Mexico; stratigraphic and structural evidence for and against the megashear hypothesis
-The eastward migrating Cretaceous Sierra Nevada-Peninsular Ranges batholith; Mid Cretaceous intra-arc disturbances
-Mid Cretaceous-Early Tertiary tectonics in southern California: the Vincent-Orocopia-Chocolate Mountains-Rand thrusts;
the eastern Peninsular Ranges mylonite zone
-Late Cretaceous-Early Tertiary Laramide orogeny in Colorado, Arizona, Sonora, and southeastern California
-Early-Middle Tertiary tectonic events along the Cordillera:
transition from compressional to extensional tectonics
-Crustal extension in the Colorado River region and in southeastern Arizona; models for continental extension
-Middle Tertiary extension in Sonora, Mexico
-Eocene-mid Miocene tectonics of southern California: pre-San Andreas continental margin basin development and magmatism
-Mid Miocene-Recent evolution of the San Andreas fault system
-Pliocene-Recent tectonics in the LA basin and central Transverse Ranges: Glendora volcanics, Puente Formation, and the Pasadenian orogeny
**February 16 (Friday) is another academic holiday**
February 23-25 Friday PM-Sunday PM field trip to Borrego Springs/Salton Trough or the Mojave Desert
March 2 Friday PM field trip to Cal Poly’s San Jose Hills and Puddingstone Reservoir—Intro to LA Basin tectonics
March 9-11 Friday PM-Sunday PM field trip to Borrego Springs/Salton Trough or the Mojave Desert
**March 17 (Wednesday): Final Exam--Please Allow Three Hours**