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Stratigraphy and Evolution: Using Fossils to Tell "Deep Time"

Stratigraphy and Evolution: Using Fossils to Tell "Deep Time"

Developed by Hilary Clement Olson, The University of Texas at Austin Institute for Geophysics

How to cite this work: Olson, H.C. 2011. Stratigraphy and Evolution: Using Fossils to Tell “Deep Time,” TXESS Revolution, WEB REFERENCE, Date Accessed.


Geologists estimate the Earth is 4.6 billion years old. This span of time has been subdivided and the units arranged into a geologic time scale. The study of historical geology, the rocks and fossils associated with the Earth’s history, present the student with the nature of time within a geologic context.

Through this activity students will learn about the earliest concepts of telling time in rocks using fossils: relative age dating using the various flora and fauna present. This allows for the construction of a relative geologic time scale, namely, one that is not tied to absolute ages. One of the important objectives of this activity is for participants to discover the concept of ‘range’ of a fossil when fossil distribution is looked at in stratigraphic order. The activity has mutiple solutions which reflects the reality of using fossils alone to construct a geologic timeline. 

An exploration of William Smith's concept of faunal succession, Charles Lyell’s early application of relative age dating and the subsequent influence on Charles Darwin’s theory of evolution as developed on The Beagle is included. The concept of “deep time” will be explored through the fossil record of foraminifera.

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Development, Research and Testing of the Activity

The activity has been shared with more than 200 teachers in Texas at a variety of workshops. It was implemented in the following teacher professional development workshops: (1) Revolution Teacher Workshops (2006), supported by the Texas Education Agency; and the TXESS Revolution Project (2007 - 2012), supported by the National Science Foundation Opportunities for Enhancing Diversity in the Geosciences under NSF Grant No. 0703687. Teachers who attended the TXESS Revolution rated the activity as shown below. 

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation or the Texas Water Development Board.

Activity Rating

Rating: 1=Poor; 5 = Excellent 

Interesting - 4.44; applicable to the implementation of guided inquiry in the classroom - 4.38; applicable to my use of in-class technology - 4.28    (n = 24)                                


Thanks to the many teachers and students who have evaluated and given very constructive feedback for this activity on Faunal Succession. Images for fossil foraminifera cards are after Jones, D.J., 1956, Introduction to Microfossils, Harper, 406p.