David J. Davies
Department of Geology and Geography
Centenary College of Louisiana
Shreveport, LA 71104

Level: Elementary to Middle School


Anticipated Learning Outcomes





  1. The students will engage in the "Fossil Detective Game" by trying to determine the age of the "formation" in the pit, using its enclosed fossils.
  2. A short introductory lesson will explain three ideas:
    a) The portion of the rock cycle where sedimentary rocks are formed from the weathering of igneous rocks.
    b) The geologic time scale seen in the layers of rock whose history can be "read" as the pages of a book. The oldest rocks, as the oldest periods on the time scale, are on the bottom.
    c) This history can be read, and thus the age of the rocks determined, because of the changes in life (evolution) through time.
  3. The students will be allowed to be "Fossil Detectives" and search for clues as to the age of the "formation." They will dig for fossils that have been previously buried. There are two goals:
    a) Find a large index fossil, then identify it by taking it to the geologic time scale and matching it with the attached fossils. The age of the deposit is then determined. [Whereas any index fossil can be used, it is recommended that Mesozoic fossils be employed; thus, the deposit will be of "The Age of Dinosaurs"]. Assistance from the instructor should be available for younger students.
    b) Find smaller fossils (preferably shark's teeth); at the end of the exercise, the student can be allowed to keep his or her favorite fossil found, thus, retaining a tangible memento to reinforce the lessons learned.

Results, Discussion, and Conclusions

  1. Students will discover for themselves that this "formation" was deposited during the Age of the Dinosaurs, and that many other animals (e.g., sharks and Exogyra) lived at that time.
  2. A group discussion should follow as to why no dinosaur remains were discovered, if this is a Mesozoic deposit.
  3. Further discussion should emphasize why this deposit could not have been Cenozoic or Paleozoic in age, even though sharks are still alive today. Quesions regarding fossils likely to be found in underlying older formations, as well as in now eroded overlying younger units, will lead to an understanding of stratigraphic principles. Additonal discussions could emphasize the relevance of the dinosaurs' extinction to our current environmental problems, as well as the role of evolution during the immensity of geologic time in forming the fossil record.

Related Activities

(This activity is modified from our 1989 Red River Revel "Revel in Geology!" mock-dig, where over 3300 children and their parents participated during its one week duration).

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