A Geologic Safari of the East African Rift and the Newark Basin: Why these areas are more alike than you know


Margaret H. Benoit, The College of New Jersey
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Summary

Students visualize earthquake, volcano, topographic data, geologic maps, and photographs of geologic structures to identify similarities and differences between the Newark Rift Basin and East African Rift using interactive powerpoint presentations and GeoMapApp.

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Learning Goals

  • learn about continental rifts and their evolution through time
  • synthesize information about earthquakes, volcanoes, topographic data, bedrock geology, and photographs of geologic structures for two continental rifts at different stages of evolution
  • identify volcano type from topographic profile plots
  • demonstrate facility with GeoMapApp
  • visualize topographic data in map and profile views

Context for Use

  • This activity, though specifically targeted for students from New Jersey, could be easily adapted to be instructive for students living anywhere along the East Coast of the US or in any region containing an aulacogen.
  • Students should be familiar with plate tectonics, volcanism, faults, igneous and sedimentary rocks, and groundwater.
  • It can be used as a classroom activity led by an instructor, used by students at a computer terminal for an in-class exercise, or used by students at home.
  • Students should have some familiarity with GeoMapApp, but it is not essential for students to have to engage in this activity

Description and Teaching Materials

First, students spend time thinking about what geologic and landscape features they would expect to see at a continental rift. A powerpoint and handout will help them target their thinking in terms of what kinds of faults, volcanic features, rock types, and landscape features (lakes, escarpments, etc) they would expect to be present. This PowerPoint presentation also explores the East African rift in the context of this background. The middle component of the exercise involves student exploration of the East Africa Rift using the GeoMapApp visualization tool, with an associated handout to guide their activity. Finally, a powerpoint and related handout introduces the Newark Rift Basin and highlights several geologic aspects of the regions. As students view the presentations and work with GeoMapApp, they will answer questions about each topic on the handouts. Students are asked to think about what this divergent plate boundary would look like several hundred million years in the future, and are asked to compare and contrast the two regions.The materials for this lesson include 2 PowerPoint presentations (and corresponding student guide handouts) containing pictures, maps, and figures with information on the East African Rift and Newark Basin, as well as a handout describing an activity with GeoMapApp to explore the East African Rift. structures in the Newark Basin.
East Africa Rift background powerpoint (PowerPoint 5MB May28 09)
East Africa Background handout (Microsoft Word 27kB May28 09)
GeoMapApp handout (Microsoft Word 38kB May28 09)
New Jersey PowerPoint (PowerPoint 7.8MB May28 09)
New Jersey Handout (Microsoft Word 12kB May28 09)

Teaching Notes and Tips

The entire activity is planned as a 3 part exercise:
  1. The first part uses the East African Rift powerpoint and handout to explore the background of rifts and East Africa more specifically.
  2. The second part uses the handout that describes the hands-on exploration of East African Rift features using GeoMapApp.
  3. The third part is a powerpoint and handout that relates the rift features to older structures in the Newark Basin.

I have greatly simplified some of the geology of Eastern Africa for this lesson. For example, I do not discuss the fact that there are stratovolcanoes in Eastern Africa or any felsic igneous features. Students might identify these volcanoes in section #2, so this could be a jumping off point for a more in-depth discussion.

Assessment

Formal assessment of this activity is mainly accomplished through examination of the handouts and profile plots from GeoMapApp. By looking at the cross sectional plots of the rift basins, the instructor can identify whether the student correctly identified the locations of the rift basins. Students will demonstrate that the have synthesized the data provided in this mini lesson by drawing the correct conclusions in the handout #3. An instructor can also assess if the student appropriately identified the correct volcano type by examining the profile plots of the volcano and by examining the table that the student needs to fill out in handout #2.

Informally, the profile plots submitted with the lesson will enable the instructor to assess if the student has demonstrated that they are comfortable using GeoMapApp. If this is done in a lab setting, eavesdropping on students can help the instructor identify is students are having trouble with the application.

References and Resources