Tracking Sea Level and Paleoenvironments with Fossils

Pete Berquist
Thomas Nelson Community College
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Students use the Paleobiology Database Navigator to examine changes in sea level in southeastern North America throughout the Cretaceous, Paleogene, and Neogene Periods. They will plot the change in distribution of marine snails and corals to compile rudimentary paleogeographic interpretations and to describe the magnitude of sea level change during the Late Mesozoic and into the Cenozoic.

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To be used in an introductory or intermediate undergraduate course, including (but not limited to) physical geology, historical geology, and paleontology.

Skills and concepts that students must have mastered

Student should be able to:
  • Interpret a diagram of the geologic time scale and distinguish eons, eras, and periods.
  • Generally associate sedimentary rocks with depositional environments. For instance, shale is deposited in low energy environments like the deep ocean and extremely poorly sorted and angular clasts are associated with glacial environments. For more detail, see:
  • Recognize that some organisms require specific habitats, so by seeing the spatial distribution of these organisms at a specific time, we can interpret the environmental conditions at that time. Changes in the spatial distribution of these organisms show changes in environmental conditions.
  • Calculate rate of change (specifically sea level rise) and convert common units of length. For additional help with these types of calculations, see:

How the activity is situated in the course

This exercise is a stand-alone activity and can be incorporated during a variety of topics, including discussion of paleoenvironmental reconstruction, sea level, and paleobiology.


Content/concepts goals for this activity

  • Identify coastal/near-shore depositional environments.
  • Create paleogeographic reconstructions for the Cretaceous, Paleogene, and Neogene Periods of southeastern North America.
  • Describe the extent and rate of sea level change within an area over a specific time frame, based on observation of changes in the fossil record.
  • Predict causal mechanisms for sea level change within a specified time and area.
  • Predict additional organisms that could be used to identify sea level change in other areas and use the PBDB Navigator to test these predictions.
  • Determine suitable and desirable characteristics of organisms that lead to understanding the water-depth of their habitat.
  • Interpret environmental changes for an area based on the spatial and temporal change of its fossils.

Higher order thinking skills goals for this activity

  • Create maps showing the spatial and temporal distribution of specific fossils.
  • Develop a testable prediction of which fossils may be useful for determining changes in sea level.
  • Test predictions/hypotheses by collecting data from the Paleobiology Database.

Other skills goals for this activity

Description of the activity/assignment

Students will need computer access to the Paleobiology Database Navigator to show how the distribution of three groups of organisms change throughout eastern North America during the Cretaceous, Paleogene, and Neogene Periods. Based on the observed trends, students will describe how sea level changed in this area during these time frames.

In addition to computer access, students will need handouts of blank maps for each group of organisms (three total, provided in the activity) and colored pencils.

Determining whether students have met the goals

Formative assessment: If conducted in class, the instructor should walk around and mix troubleshooting advice with informal observations of whether the relevant time periods and taxa are being investigated.

Summative assessment: the numbered questions, sketches, and three maps are key summative assessment points. In particular, question 3 can be used on an test/quiz/exam for students to demonstrate their spatial understanding of depositional environments. Additionally, question 10 could be modified with different values on a problem set, homework, or test/quiz to assess students' quantitative reasoning ability.

More information about assessment tools and techniques.

Teaching materials and tips

Other Materials

Supporting references/URLs

Relevant web sites that students will need:

Potentially useful links for depositional environments:

Help with math/quantitative reasoning skills: