Introducing Geologic Map Interpretation and Cross Section Construction Using Google Earth

Barb Tewksbury
Hamilton College
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A highly effective, non-traditional approach for using Google Earth to teach strike, dip, and geologic map interpretation.

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This approach and set of activities was developed for a structural geology course as an introduction to geologic map interpretation. It could easily be adapted for an introductory geology course.

Skills and concepts that students must have mastered

None (which is why it could be easily used in an intro geo course)

How the activity is situated in the course

This set of activities starts during the first week of the semester.


Content/concepts goals for this activity

The whole litany of topics associated with geologic mapping, map interpretation, and simple cross section construction

Higher order thinking skills goals for this activity

Students will be able to visualize units, contacts, and structures in 3D, be able to make their own geologic maps using Google Earth images, and draw cross sections of inclined, folded, and faulted units.

Other skills goals for this activity


Description of the activity/assignment

The approach to teaching geologic map interpretation described in the materials departs significantly from the typical approach, which commonly involves defining strike and dip and types of contacts, drawing cross sections in areas with no topography and working with paper block models and PlayDoh for visualiztion, teaching outcrop patterns and rule of Vs in areas with topography, and then having students practice map interpretation and cross section construction.

The approach describe in materials listed here uses the powerful 3D viewing capability and the remarkable satellite images of Google Earth to help students really visualize structures. The approach does the following:

* Emphasizes mapping before map interpretation in order to help students visualize, rather than memorize.
* Starts by having students do geologic mapping in Google Earth before they know anything about strike, dip, or types of contacts.
* Has students work first with inclined units and contacts in areas with topographic relief, using Google Earth 3D view to develop an understanding of dip.
* Has students sketch simple cross sections of their own geologic maps and use Google Earth 3D view to help them visualize the relationships.
* Derives strike after students understand dip.
* Has students work with vertical contacts next, then horizontal contacts, and, finally, folded and faulted contacts.
* Gives students lots of practice in mapping in Google Earth and creating their own cross sections in areas of increasing complexity.
* Follows with interpretation of existing geologic maps coupled with use of maps in the field.

Determining whether students have met the goals

Homework assignments, projects, and take-home exams are graded, in-class work is not.

More information about assessment tools and techniques.

Teaching materials and tips

Other Materials

Supporting references/URLs

All of the information for this approach (including downloads for several assignments and projects) can be found beginning on the following web page: