Marine Microfossils and Biostratigraphy

Mark Leckie, University of Massachusetts, Amherst; Kristen St. John, James Madison University (; Megan Jones, North Hennepin Community College; Kate Pound, St. Cloud State University; Larry Krissek, Ohio State University

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This exercise set explores marine microfossil distributions in deep-sea cores. Students are guided to apply a biostratigraphic zonation and interpret relative age, correlate from one region of the world ocean to another, and calculate rates of sediment accumulation.



Undergraduate courses in paleontology, oceanography, marine geology, sedimentology, introduction to climate change, historical geology. It can be adapted up or down - it has been successfully used with high school teachers and graduate students.

Skills and concepts that students must have mastered

Pre-req: basic (high school level) biology and Earth science.

How the activity is situated in the course

It is a 5-part sequenced exercise (see Instructor Notes). It is based on real scientific data sets and figures from the scientific literature. All parts have been used in upper level geology major classes. Parts 2-4 have been used in large general education classes to help students understand how geologic ages and sedimentary rates can be determined for a sedimentary sequence. Some exercise parts can be assigned as homework as pre-class assignments. A brief-synthesis lecture on the main marine microfossil groups could follow Part 1 or replace Part 1.


Content/concepts goals for this activity

Goal: to explore the scientific processes and rational for using fossils to determine age, with a focus on marine microfossils.

Objectives: After completing this exercise your students should be able to:
1. Infer paleoecological and paleobiological information using microfossil distribution data.
2. Make observations about microfossil abundance data and make hypotheses to
explain their observations.
3. Apply a biostratigraphic zonation to microfossil abundance data and use it to interpret relative ages.
4. Use microfossil data to calculate rates of sediment accumulation.
5. Use microfossil data to test the reliability of microfossil datum levels in
multiple locations, and correlate sedimentary sequences at different locations.

The following topics are addressed in this exercise set: phyto- & zooplankton distributions, abundances & diversity; geologic timescales; sea level change; trophic levels & productivity; age determination using fossils, index fossils, biozones, datums, first/last occurrences; extinction; sediment accumulation rates, age-depth plots; calibration & correlation of different types of data; unconformities, hiatus; reliability and uncertainty.

Higher order thinking skills goals for this activity

Making observations; plotting data; forming questions; making hypotheses and predictions; interpreting data from photos, diagrams, tables, and graphs; calculating rates; pattern recognition; integrating and drawing broad conclusion.

Other skills goals for this activity

Working with real data, working in groups; working from multiple perspectives; written communication; making persuasive and well supported arguments.

Description and Teaching Materials

Microfossils are important, and in places the dominant constituents of deep sea sediments. The shells/hard parts of calcareous microfossils can be geochemically analyzed (e.g., by stable isotopes of oxygen and carbon), which are powerful proxies (indirect evidence) in paleoceanography and climate change studies. Microfossil evolution has provided a rich archive for establishing relative time in marine sedimentary sequences. In this exercise set students gain experience using microfossil distributions in deep-sea cores to apply a biostratigraphic zonation and interpret relative age, correlate from one region of the world ocean to another, and calculate rates of sediment accumulation. In Part 3.1, students learn about the major types of marine microfossils and their habitats; students consider the role of primary productivity in the world oceans, the geologic record and diversity through time of major microfossil groups, as well as the relationship between microfossil diversity and sea level changes through time. In Part 3.2, students explore microfossil distribution in a deep-sea core and consider microfossils as age indicators. In Part 3.3, students apply microfossil first and last occurrences (datum levels) in a deep-sea core to establish biostratigraphic zones. In Part 3.4, students use these same microfossil datum levels to determine sediment accumulation rates. In Part 3.5, students explore the reliability of microfossil datum levels in multiple locations.

Activity Description/Assignment:
The student activity can be downloaded from: select Chapter 3, Marine Microfossils and Biostratigraphy.

Teaching Notes and Tips

Instructors may find it useful to print out large-scale (11x17) handouts of the biostratigraphic table 3.2. To do so, download and print: Biostratigraphic Table 3.2 (TIFF 19.3MB Jul23 15)

Instructors Notes: See the pdf file Instructor Notes (Acrobat (PDF) 325kB Jul23 15).

In addition go to: for suggested supplemental materials (Chapter 3).

Solution Set: A pdf file that contains a detailed answer key and additional suggestions for instructors can be obtained by emailing Kristen St. John (


There are several ways an instructor can assess student learning after completion of this exercise. For example: students should be able to answer the multiple choice and short answer questions included in the instructor guide after completing this exercise set. To obtain a copy of the instructor guide email Kristen St. John ( In addition, the instructor could select additional scientific ocean drilling biostratigraphic tables that exist for nearly all DSDP-ODP-IODP sites (see,, and and develop an assessment instrument that models the activity tasks used in this exercise.

References and Resources

This exercise is an open access chapter from:

St. John, K., Leckie, R.M., Pound, K., Jones, M., and Krissek, L., 2012. Reconstructing Earth's Climate History: Inquiry-based Exercises for Lab and Class. Wiley-Blackwell, 485p;

For other open access chapters from this book go to:

References used in constructing this exercise include:

Brown, P.R., 2005, Cenozoic calcareous nannofossil biostratigraphy, ODP Leg 198 Site 1208 (Shatsky Rise, Northwest Pacific Ocean). Proceedings of the Ocean Drilling Program, Scientific Results, Bralower, T.J., et al. (eds), vol. 198, College Station, TX, Ocean Drilling Program, pp. 1–44.

Gradstein, F., 1987, Report of the Second Conference on Scientific Ocean Drilling (Cosod II), European Science Foundation, Strasbourg, France, p. 109.

Kameo, K. and Bralower, T.J., 2000, Neogene calcareous nannofossil biostratigraphy of Sites 998, 999, and 1000, Caribbean Sea. In Proceedings of the Ocean Drilling Program, Scientific Results, vol. 165, Leckie, R.M., et al. (eds), College Station, TX, Ocean Drilling Program, pp. 3–17.

Katz, M.E., et al., 2005, Biological overprint of the geological carbon cycle. Marine Geology, 217, 323–38.

Shipboard Scientific Party, 1992, Site 846. In Initial Reports of the Ocean Drilling Program, vol. 138, Mayer, L., et al., College Station, TX, Ocean Drilling Program, pp. 256–333; doi:10.2973/

Shipboard Scientific Party, 2002, Explanatory notes. In Proceedings ODP, Initial Reports of the Ocean Drilling Program, vol. 198, Bralower, T.J., et al., College Station, TX, Ocean Drilling Program, pp. 1–63. doi:10.2973/

Young, J.R., 1998, Neogene. In Calcareous Nannofossil Biostratigraphy, Bown, P.R. (ed.), Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 225–65.

Additional Resources:

An excellent resource for identification of marine microfossils is a new digital atlas of marine microfossils which can be accessed at Select: IODP Technical Note 2. (PDF; 105.9 MB) IODP Smear Slide Digital Reference for Sediment Analysis of Marine Mud. Part 2: Methodology and Atlas of Biogenic Components (2015)​10.2204/​ .

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