This unit tells the story of the development of the theory of plate tectonics. The students take the same journey of discovery as scientists did. This helps them understand that science is a human endeavor. We start this unit by looking at a map of the world and reviewing the names of continents and oceans. Could these continents have once been joined together? If so, how is that even possible? Why aren’t they together now? I tell the story of Abraham Ortelius, the Dutch map maker, who in his work Thesaurus Geographicus (1596), suggested that the Americas were “torn away from Europe and Africa . . . by earthquakes and floods” and went on to say: “The vestiges of the rupture reveal themselves, if someone brings forward a map of the world and considers carefully the coasts of the three [continents].” Then we learn about Alfred Wegener’s continental drift theory by analyzing and interpreting the same data he collected. Students are surprised to find out that his theory was rejected, even ridiculed by some. One of the main reasons his theory was rejected was because he could not explain the mechanism that could cause the continents to drift. This leads us to researching the layers of the earth because if we learn how earth is structured, then this might help us figure out how it functions. Through the development and use of models, the students learn that there are convection currents in the asthenosphere. Could this help explain how the continents moved? They learn that Arther Holmes proposed this idea in 1929 but it was largely ignored until the 1960s. We move on to learn more about what’s happening at the ocean crust. Due to better technology, scientists were able to explore the ocean floor leading to such discoveries as mid-ocean ridges and geomagnetic patterns. How does this data help answer our questions? These discoveries led to the idea of the sea-floor spreading process proposed by Harry Hess and Robert Dietz. As seismic wave detection improved and became available world wide, the patterns of earthquakes and volcanic activity reinforced the idea the the crust is broken into pieces called plates. Students will also look for patterns in earthquake and volcanic activity to hypothesize where the plate boundaries are located. How can this data help us understand why the Earth is so dynamic? What causes the ground to shake violently, volcanoes to erupt, mountain ranges to rise, islands to form, and the recycling of crust (rock cycle)? Then we end with using geoscience data to start putting together the pieces of the puzzle that is the history of earth.
Unit’s Lesson Progression
Click on a lesson title to link to the lessons’ overview and resources. Eventually there will be complete 5E model lesson plans to download (see About Me update). I will be including Face to Face tools in the lesson plans.”This family of tools was developed to help students to construct and revise evidence-based explanations and models for complex phenomena. Face-to-face tools are used with students (that’s where the name comes from) to represent and work on their current ideas.” I will also be adding these strategies: Tools | Scaffolding for writing & talking science
- Top Plate Tectonic Misconceptions
- Continental Drift Theory–Accept or Reject?
- Earth’s Inner Structure
- Evidence Gathered from the Sea Floor
- The Theory of Plate Tectonics–Accept or Reject?
- Rock Cycle
- Piecing Together Earth’s History
- Background Info: USGS: Developing the Theory
- Ortelius World Map
- Timeline of the development of the theory of plate tectonics