Earth Sciences 3314b, Sedimentary Petrology, Winter 2022
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Earth Sciences 3314b, Sedimentary Petrology, Winter 2022 Instructor: Dr. Guy Plint, Rm. BGS 1072, 519-661-3179; gplint@uwo.ca TA. There will be no TA for this course Lectures-Online: Because of the abrupt shift to on-line instruction in response to the Covid- Omicron wave, lectures for at least January 2022 will be in the form of video recordings, available on my dedicated You-Tube channel. Links to individual lectures will be posted via OWL in the appropriate sequence. You may watch the lectures at a time that suits you, but you are advised to keep to a regular weekly ‘class’ schedule. During Winter 2021, when we had to adopt the same system, a few students let their ‘class attendance’ slide, and had a hard time catching up at the end! Lectures-In Person: UWO is proposing a return to in-person classes starting in February 2022. If that situation becomes a reality, then normal classes are scheduled on Monday and Wednesday, 11:30-12:30, in University College room UC-2105 Labs-Online: This course is concerned primarily with the small-scale details of sedimentary rocks, which involves observation and description of thin sections. All the thin sections have been digitally imaged and these images will be posted to OWL at the appropriate time. Labs-In Person: If we are permitted to resume normal lab sessions, these will be held on Wednesday, 2:30 – 5:30 pm. We might use BGS Rm. 1065, or may be obliged to move to the larger BGS 1015. Only if the Wednesday lab is full, will a second lab, Monday, 6-9 pm be opened. --------------------------------------------------------------------------------------------------------------------- Brief Description: Identification and description of various types of siliciclastic, carbonate and chemical sedimentary rocks; sedimentary textures; sedimentary structures; depositional environments; diagenetic processes that alter the original properties of primary sediments. Prerequisites: Earth Sciences 2200a/b, Earth Sciences 2206a/b Statement on Requisites: Unless you have either the requisites for this course or written special permission from your Academic Counselor to enroll in it, you may be removed from this course and it will be deleted from your record. This decision may not be appealed. You will receive no adjustment to your fees in the event that you are dropped from a course for failing to have the necessary prerequisites. Importance of Sedimentary Petrology. About 90% of the Earth's surface is covered by unconsolidated sediments or sedimentary rocks. They record the entire history of the hydrosphere, atmosphere and biosphere of Planet Earth. Ancient sedimentary rocks were deposited in a wide range of sedimentary environments that exist today, and therefore the study of modern environments enables us to interpret ancient sediments in terms of physical, biological and chemical depositional conditions. Ancient sedimentary rocks also include, however, some
rock types for which no modern analogues exist. Naturally, interpretation of these rocks is more
difficult.
Once deposited, sediments undergo processes of diagenesis, including physical,
biological and chemical processes that bring about compaction, cementation, and
recrystallization that turn loose sediment into a rock. The study of sedimentary rocks allows one
to deduce processes and environments of deposition, paleogeography and paleoclimatology.
Sediments contain the record of life on Earth, and the integration of sediments and fossils is
essential in detailed paleoenvironmental and paleoecological analysis. Sedimentary rocks also
contain a wealth of economic minerals, and an understanding of depositional and diagenetic
conditions is essential to efficient exploitation of these resources. In view of this applied aspect,
I have designed lab exercises that will, to a fair degree, replicate datasets used in industry.
In order to understand the origin and genesis of sedimentary rocks, it is essential to first
objectively Describe the characteristics of the rocks. That is what Petrography is all about.
Good scientific interpretation can only flow from good observations and descriptions.
To those ends, the Lectures will start by refreshing your memory of some aspects of sedimentary
geology that were covered in ES2260a. We will then move on to a more in-depth review of the
characteristics and origin of the main types of clastic and carbonate sedimentary rocks.
The emphasis of the laboratory component of this course will be on developing your powers of
observation at the hand specimen and thin section scale. To this end, I remain firmly convinced
of the importance of the old-fashioned skill of drawing, in that drawing is a form of forced
observation. Your two lab exercises will therefore involve producing representative drawings of
some, if not all (lab time permitting) the thin sections that you have studied.
The thin section samples that you describe will then be interpreted in terms of Depositional
Environments, and in the context of the regional stratigraphy and basin setting provided by a
seismic cross-section. A report on each of the two lab exercises, ‘A’ and ‘B’ will be completed
during the term, each taking four to five weeks. Each report will integrate the sedimentary
petrology observed in thin sections, with the vertical successions of facies observed in synthetic
cores in order to reconstruct depositional environments. The succession of depositional
environments, and history of basin sedimentation, will be interpreted from the seismic data
provided. There will be no weekly hand-in labs.
COURSE SYLLABUS
Approximate Class Schedule
Date Lectures Labs
Jan 10 Introduction; Fluid flow &
bedforms
Jan 12 Fluid flow & bedforms Jan 12. Sedimentary exercise A, part I
Jan 17 Fluid Flow & bedforms
Jan 19 Fluid Flow & bedforms Jan 19. Sedimentary exercise A, part IIJan 24. Clastics – Composition &
Terminology
Jan 26. Clastics – Sorting, Texture & Jan 26. Sedimentary exercise A, part III
Fabric
Jan 31 Clastics – Mudstones;
Depositional Environments
Feb 2 Clastics – Depositional Feb 2. Sedimentary exercise A, part IV
Environments
Feb 7 Clastics - Diagenesis
Feb 9 Carbonates – Non-Skeletal Grains Feb 9. Sedimentary exercise A, part V
Feb 14 Carbonates – Skeletal Grains
Feb 16. Carbonates – Skeletal Grains, Feb. 16. Mid Term test in-person in lab time or 15 mins.
Classification Schemes Oral in lab time, depending on circumstances.
Friday February 18th, Exercise A due 5 pm
Feb. 19- Spring Break- No classes No labs
27
Feb 28 Carbonates – Sedimentary
Structures
Mar 2 Carbonates – Depositional Mar 2. Sedimentary exercise B, part I
Environments
Mar 7 Carbonates – Depositional
Environments
Mar 9 Carbonates- Depositional Mar. 9. Sedimentary Exercise B, part II
Environments
Mar 14 Carbonates-Diagenesis
Mar 16 Carbonates – Diagenesis, Mar 16. Sedimentary Exercise B, part III
dolomites
Mar 21 Carbonates – Dolomite
Mar 23 Carbonates - Evaporites Mar 23. Sedimentary exercise B, part IV
Mar 28 Siliceous sediments
Mar 30 Iron Rich Sediments Mar 30. Sedimentary exercise B, part V
April 4 Phosphorites
April 6 Organic-Rich Sediments Wednesday April 6. Exercise B due, 5 pm.
April…. ORAL Final Exam, 20 minutes Date to be Determined
COURSE MATERIALS
Any sedimentology textbook can be used as a resource, but none are required.
I would recommend:
Sedimentology & Stratigraphy, by Gary Nichols, 2nd Edition
Principles of Sedimentology and Stratigraphy by Sam Boggs. Both 4th and 5th Editions are fine
EVALUATION
Mid-Term Test, in-person in lab time, Wednesday February 16th: 20%
Lab Exercise A due Friday 18th February at 5 pm; 25%
Lab Exercise B due Wednesday April 6th at 5 pm; 25%
Final Exam will be oral, 20 mins, via Zoom, or in-person, depending on
circumstances. Date TBA: 30%Learning Outcomes: Upon successful completion of this course, students should be able to: 1. Identify the most common types of physical sedimentary structure, and describe their origin in terms of fluid flow. 2. Identify the principal detrital, biogenic and chemical components of sedimentary rocks in thin section. 3. Recognize and understand the principal features that develop during diagenesis of sedimentary rocks. 4. Be aware of the principal depositional environments of siliciclastic and carbonate sediments, and be able to identify those environments on the basis of rock characteristics. 5. Apply the geological timescale as a basis from which to analyse the history of a sedimentary basin. 6. Apply the knowledge and concepts above to analyse a variety of real-world stratigraphic data- sets, including seismic reflection profiles and synthetic cores in order to deduce ancient depositional environments, processes, and basin-forming mechanisms. 7. Analyse incomplete geological data in order to make reasoned predictions about the distribution of economically-valuable rocks, and to assess the level of uncertainty in those predictions. Scholastic offences are taken seriously and students are directed to read the appropriate policy, specifically, the definition of what constitutes a Scholastic Offence, at the following Web site: http://www.uwo.ca/univsec/handbook/appeals/scholoff.pdf Plagiarism is a serious academic offence. The UWO Senate Academic Handbook defines plagiarism as "The act of appropriating the literary composition of another, or parts or passages of his writings, or the ideas or language of the same, and passing them off as the product of one's own mind.” Students must write their assignments in their own words. Whenever students take an idea, or a passage from another author, they must acknowledge their debt both by using proper referencing such as citations. For more information see Scholastic Offence Policy in the Western Academic Calendar. If you are unable to meet a course requirement due to illness or other serious circumstances, you must provide valid medical or other supporting documentation to the Academic Counseling office as soon as possible and contact your instructor immediately. It is the student's responsibility to make alternative arrangements with their instructor once the accommodation has been approved and the instructor has been informed. In the event of a missed final exam, a "Recommendation of Special Examination" form must be obtained from the Academic Counseling Office immediately. For further information please see:
http://www.uwo.ca/univsec/handbook/appeals/medical.pdf A student requiring academic accommodation due to illness, should use the Student Medical Certificate when visiting an off-campus medical facility or request a Records Release Form (located in the Academic Counselling office) for visits to Student Health Services. The form can be found here: https://studentservices.uwo.ca/secure/medical_document.pdf Accessibility Statement Please contact the course instructor if you require material in an alternate format or if you require any other arrangements to make this course more accessible to you. You may also wish to contact Services for Students with Disabilities (SSD) at 661-2111 x.82147 for any specific question regarding an accommodation. Support Services Students who are in emotional or mental distress should refer to mental Health@Western http://www.uwo.ca/uwocom/mentalhealth/ for a complete list of options about how to obtain help. Registrarial Services are available at: http://www.registrar.uwo.ca/, and Student Support Services are listed at http://westernusc.ca/services/
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