Geologic History Lab Pair
Summary
This is a pair of labs that incrementally prepare students to interpret the geologic history of a rock sequence. The first lab introduces students to depositional environments and fossils. The second lab presents a sequence of rocks from Bryce, Zion and the Grand Canyons. During the two labs, students learn first to interpret depositional environments from sedimentary rocks and then apply this to interpreting the changing environments through time in order to create a geologic history for this area of the American southwest.
Context
Audience
These two labs are part of an introductory geology course for both majors and non-majors. The class includes students ranging from first-years to seniors.
Skills and concepts that students must have mastered
FOR DEPOSITIONAL ENVIRON. LAB:
- Ability to describe and identify rocks
- Ability to describe and identify rocks
- Ability to describe and identify small group of fossils using id. charts
- Familiarity with depositional environments and their characteristics
- Familiarity with depositional environmental indicators
How the activity is situated in the course
These two labs immediately follow our rock identification labs as one way to show students how to apply their rock identification skills and how rocks are used as tools to interpret the earth's history.
Goals
Content/concepts goals for this activity
FOR DEPOSITIONAL ENVIRON. LAB:
- Learn to recognize environmental indicators in sedimentary rocks
- Learn to describe and identify a small number of fossils
- Learn several different depositional environments and their characteristics
- Recognize the spatial relationships between different depositional environments
- Learn to sequence rocks in order of relative age (principle of superposition, cross-cutting relationships)
- Learn concept of transgressions and regressions
- Learn that unconformities represent erosional surfaces
- Learn to recount a geologic history from a sequence of rock
Higher order thinking skills goals for this activity
FOR DEPOSITIONAL ENVIRON. LAB:
- Learn to relate the textural/color/etc. features in a sedimentary rock to the characteristics of depositional environments to understand what determines which sediments are deposited in which environment
- Learn to use the presence or absence of particular fossils to aid in the determination of the depositional environment
- Learn to attribute change to something (cause and effect)
Other skills goals for this activity
FOR DEPOSITIONAL ENVIRON. LAB:
- Develop observation and description skills
- Begin the process of coalescing various forms of data to make interpretations
- Make interpretations with larger amounts of data
- Practice clear, complete essay writing
Description of the activity/assignment
The goal of this pair of labs is for the students to learn to apply rock and fossil identification skills to determining rock formations, sedimentary depositional environments, age ranges, and, ultimately, to writing a geologic history of a sequence of rocks from Bryce, Zion, and Grand Canyons. During the first of the two labs, the students learn to make fossil and sedimentary structures identifications. They add these skills to their rock and mineral identification skills to make interpretations of the sedimentary environments along a generalized profile from terrestrial to offshore locations. During the second lab, they apply these skills to a sequence of rocks from the southwestern U.S. to interpret the environmental changes that have occurred over time. They also begin to learn how to use fossils to determine age ranges for these changing events. Once they put together all of their data, they construct a stratigraphic column and piece together a written narrative of the geologic history of the area. The students work in groups to collect their data and determine their stratigraphy. They write their geologic histories individually. The students learn how to apply their skills and knowledge to make interpretations and also learn how to support their determinations with data.
Determining whether students have met the goals
For the Depositional Environment lab, students complete a diagram that includes recording their rock, fossil, and sedimentary structure identifications. Students also answer some questions to summarize what they have learned.
For the Geologic History lab, we ask students to write an essay presenting the geologic history of Bryce, Zion and Grand Canyons.
More information about assessment tools and techniques.For the Geologic History lab, we ask students to write an essay presenting the geologic history of Bryce, Zion and Grand Canyons.
Teaching materials and tips
- Activity Description/Assignment (Microsoft Word 2007 (.docx) 39kB Feb16 12)
Other Materials
- Depositional Environment descriptions chart (Excel 2007 (.xlsx) 17kB Feb16 12)
- Fossil, Rock, Time Range charts (Excel 2007 (.xlsx) 17kB Feb16 12)
- Background information-geologic time (Microsoft Word 2007 (.docx) 23kB Feb16 12)