PROBLEM: How can the principles of stratigraphy be used to do
relative age dating?
Exercise I. This drawing shows a cross-section, or a side view,
of the rock layers below the Earth’s surface. The trees and water show
where the surface is. Each rock layer is identified by a letter. Some of
the rock layers contain fossils. Using the principles of stratigraphy,
answer the following questions about the cross section.
1. Which rock layer is the oldest? Which rock is the youngest? Which
principles helped you determine your answer?
2. Between what two layers has erosion occurred? How can you tell?
3. Which rock units have been affected by mountain building? How can
4. Which type of fossil is the oldest? Which stratigraphic principles
helped you answer this question?
Correlate the appropriate rock units by drawing a line between the
cores. You are given one clue in defining bed "A." Color the
appropriate units and name them logically. Make a legend so your teacher
can easily see the results.
1. Describe what units are missing in section 3.
Exercise III. Correlate the appropriate units. Label the cores.
Draw a line between units that match and color them appropriately.
Create a legend using one of the cores. Can you interpret under what
environmental conditions these units were deposited (i.e., deep or