Sedimentary Geology GEOL 330

Janis Treworgy,
Principia College

Summary

The course covers the many aspects of sedimentary rocks – petrography of sedimentary rocks, sedimentary processes, depositional environments, facies analysis, and principles of stratigraphy. Practical skills are taught from field and lab work through describing and correlating local sections and cores, interpreting and correlating downhole geophysical logs, and creating structure maps, isopachous maps, and cross sections.


Course Size:
less than 15

Course Format:
Integrated lecture and lab

Institution Type:
Private four-year institution, primarily undergraduate

Course Context:

This is an upper level undergraduate course for geology minors who have taken Physical and Historical Geology. Lecture and lab are integrated in 2 class periods per week, each nearly 3 hours in length.

Course Content:

The course follows a textbook with reading assignments and lectures to review key concepts. Each class includes labs or field work in the local area. Students learn to observe and describe hand samples, sand samples under the scope, thin sections, rock cores, and outcrops. They learn to classify the rocks and to interpret their depositional settings. They learn to draw stratigraphic columns of out core and outcrop sections and to correlate the columns. They also learn to read geophysical logs, contour structure maps, and draw structural and stratigraphic cross sections.

Course Goals:

Students will be able to:
  • Describe and classify sedimentary rocks from hand specimens and thin sections
  • Measure, describe, and correlate stratigraphic sections in outcrop and subsurface (cores and geophysical logs) and draw detailed stratigraphic logs
  • Determine environments of deposition for a sequence of rocks based on composition, texture, fossils, and sedimentary structures
  • Create structure maps, isopachous maps, and cross sections
  • Think more like a geologist by being able to make interpretations from the above tools and visualizing 3-D relations of rocks

Course Features:

We are fortunate to have 2 cores of the Silurian through Mississippian section taken from our campus and one long outcrop section 7 minutes from campus that exposes rocks of the same section from the Silurian through the Mississippian. I have students first describe the cores and become familiar with those techniques as well as the rock units. Then we spend 4 class periods in the field describing the outcrop section. We also look at thin sections of the core, which allows them to compare the level of detail possible in thin section, but the importance of the bigger context as well. Our local section is primarily carbonates and shale. We take a one-day field trip to southern Illinois to see sandstone outcrops. We also spend a great deal of lab time looking at thin sections of siliciclastics and carbonates. We have a lab on sedimentary structures too.

Course Philosophy:

I prefer to teach by having the students look at examples of what we are learning about. Most of my students learn best by hands-on experiences. I do include lecture as I have found that they do not grasp the readings enough on their own, and that seems to be the best way for me to transfer some information in a more organized way for them.

Assessment:

They have labs that we do parts of together, but that they have to finish on their own. Then we review them in class. These cover describing sands, sedimentary structures, thin sections of siliciclastics, thin sections of carbonates, interpreting geophysical logs, and creating various structure maps and structural and stratigraphic cross sections. I give them 4 take-home exams on each of these aspects of the course. The exams include descriptions and interpretations (e.g. depositional setting) of the material.

Syllabus:

course schedule (Microsoft Word 2007 (.docx) 30kB May27 14)

Teaching Materials:


References and Notes:

Sedimentary Geology, 2nd edition, 2013, by Donald R. Prothero and Fred Schwab
It was between this text and Principles of Sedimentology and Stratigraphy by Sam Boggs. I felt that Prothero did a better job covering the material without going into too much detail on some of it - there is still a lot of info!

When learning to describe thin sections, we use the AAPG Memoir 28, Color Illustrated Guide to Constituents, Textures, Cements, and Porosities of Sandstones and Associated Rocks by Scholle and AAPG Memoir 77 Color Guide to Petrography of Carbonates by Scholle and Scholle that are the best teaching tools ever!
I have them read published field guide articles about the field areas we visit. I occasionally have them read an article from SEPM's Sedimentary Record.
The AAPG Memoirs mentioned above have been key in helping me teach petrography.