Virtual Field Trip to Grand Ledge, Michigan: Interpreting Sedimentary Environments
Summary
This remote field experience undertakes all stages of a sedimentation and stratigraphy field project. Students use 3-D models of outcrops and hand samples, and thin sections to analyze rock formations. They develop and test hypotheses about sedimentary environments by constructing field notes, describing siliciclastic sedimentary units, and drafting stratigraphic sections.
Context
Audience
Undergraduate required course in Sedimentation & Stratigraphy
Skills and concepts that students must have mastered
Familiarity with describing sediments and identifying sedimentary rocks and structures (including in both hand sample and thin section); using a QFR ternary plot; Walther's Law; the basics of how to draft a stratigraphic section; and a general understanding of how to interpret a depositional environment based on sedimentological and stratigraphic data.
How the activity is situated in the course
This VFT was used partway through our courses as an extended lab and class activity that was a culmination of the sedimentology portion of class, and served as an introduction to the stratigraphy portion of class. This activity was implemented during 10-12 hours of class and lab time (in-person or online) over the course of 4-5 days.
Goals
Content/concepts goals for this activity
Upon successfully completing this project, students will be able to:
- Apply their course knowledge to analyze the stratigraphic characteristics of a real-world field site through a virtual field experience
- Identify and describe lithologies from a combination of outcrop photos, 3D models, and thin sections.
- Recognize and describe bedding styles and geometry from outcrop photos and 3D models.
- Create a detailed, (litho)stratigraphic column using data from objectives 2-3 and additional strat column resources.
- Develop an interpretation of the depositional environment(s) for the stratigraphic column.
- Present final products and discuss observations and the strengths and weaknesses of different interpretations.
Summary of goals and skills: Taking field notes, making outcrop sketches, describing sedimentary rocks, utilizing QFR diagrams, drafting and correlating stratigraphic sections, making environmental interpretations
Higher order thinking skills goals for this activity
Formulation of hypotheses, synthesis of data, critical evaluation of multiple hypotheses
Other skills goals for this activity
Teamwork, time management, writing
Description and Teaching Materials
This activity can be completed in-person on paper, or online and completely virtual. The complete instructions and structure of the VFT are in the Assignment file, and a Rubric file is provided to structure assessment. The assignment is in 7 parts, to be completed in a combination of small groups, full class group, and individually. The assignment is structured to build upon students' skills and observations through multiple parts: (1) developing hypotheses based on background geology readings, (2) virtual field observations and sketches, (3) determining the lithologies present, (4) describing bedding styles and sedimentary structures, (5) drafting stratigraphic sections and interpreting depositional environments, (6) collaborating with classmates to compare sections and revise interpretations, and (7) collaborating as a class to correlate all sections, discuss interpretations, and then write individual final reflections.
Technology Needs
This activity requires students to have computer access for most components, and real-time internet access to fully interact with the virtual 3D models of samples and outcrops and to access images. No specific software is required by students, as most activities can be completed in Microsoft Office products, any pdf viewer with annotation capabilities, in Google Docs or Slides, in Google Jamboard, or by hand if necessary.
Teaching Notes and Tips
Instructors should make sure students are using consistent scaling on their stratigraphic logs, and it's also important to guide students as they start refining their observations of outcrops, so that they are focusing on primary sedimentary structures instead of jointing and weathering.
Since this is a multi-step experience that integrates knowledge on multiple subjects, students do need to be reminded of the prior knowledge they do have, and encouraged to use it.
Assessment
This VFT included both formative and summative assessments, as students worked through the entire VFT project, developing and refining their skills, and submitting deliverables at several points. The assessment rubric for all components of the project is included as a resource here.
References and Resources
1. Sketchfab collection of Grand Ledge 3D models of outcrops and hand samples used in this VFT: https://skfb.ly/6ZTzo (created by albionsedpaleo)
2. Full documentation of the Grand Ledge VFT, with all necessary materials and images, background context, assignment instructions, and assessment rubrics. This website was created to facilitate the implementation of this VFT for best accessibility for both remote and in-person students: https://grandledge.weebly.com
3. Assignment instructions (Word Doc): Grand Ledge VFT Assignment.docx (Microsoft Word 2007 (.docx) 28kB Apr25 21)
4. Assessment rubric (Word Doc): Assessment Rubric_Grand Ledge VFT.docx (Microsoft Word 2007 (.docx) 22kB Apr25 21)
5. How to take field notes guide for students: How to take field notes.pdf (Acrobat (PDF) 1.1MB Apr26 21)
6. How to construct a stratigraphic column for students: How to construct a stratigraphic column.pdf (Acrobat (PDF) 3.4MB Apr26 21)
7. Peer evaluation form for students: PeerEval for VFT.docx (Microsoft Word 2007 (.docx) 18kB Apr26 21)