Where are the Earth’s tectonic plates and their boundaries? What happens at plate boundaries? How do Earth scientists classify plate boundaries?

Part 1.  Identify the patterns of your area of expertise – volcanology, seismology, geography, geochronology - AT PLATE BOUNDARIES  Describe what you observe – do not interpret what you see, just describe the patterns  Use descriptive terms: Wide or narrow, straight or curved, symmetric or not symmetric, deep or shallow, ridge or valley, active or inactive  Identify 3-5 boundary types; color each on your transparency; define in words

Part 2.  Bring together areas of expertise – volcanology, seismology, geography, geochronology  Correlate your data sets; what collective patterns emerge?  Identify 3-5 boundary types; color each on a master transparency; define in words

Part 3.  Describe the different types of boundaries  What patterns were related in the different data sets?

Plate Boundaries Where Stuff Happens

Plate Tectonics Theory The upper mechanical layer of Earth (lithosphere) is divided into rigid plates that move away, toward, and along each other Most (!) geologic action occurs at plate boundaries in DISTINCT patterns

Compositional Crust - 2 Mantle Core Physical / Mechanical Lithosphere Asthenosphere Mesosphere

3 Basic Boundary Interactions 5 Basic Boundary Types

1. Divergent Boundaries Mid-AtlanticRidge North American Plate EurasianPlate Volcanic activity in fissures, some volcanos Shallow earthquakes, on plate boundary Young crust, symmetrical around boundary Ridge Rocks?

South American Plate Nazca Plate Antarctic Plate

Andes Mountains

2. Convergent Boundaries (a) Ocean-continent convergence Nazca Plate AndesMountains South American Plate Peru-Chile Trench Volcanos tight, parallel boundary, landward Shallow to deep earthquakes Age varies on one side of the boundary; not symmetrical Trench, mountain chain Rocks?

2. Convergent Boundaries (b) Ocean-ocean convergence Volcanos tightly spaced, parallel boundary, arc Shallow to deep earthquakes Age varies on one side of the boundary; not symmetrical Trench, volcanic island chain Rocks?

Eurasian Plate Indian Plate

Himalaya Mountains

Tibetan Plateau Himalayan Mtns. Mt. Everest

2. Convergent Boundaries (c) Continent-continent convergence TibetanPlateau Indian-Australian Plate EurasianPlate HimalayanMountains Volcanos rare, dispersed Shallow (to medium) dispersed earthquakes No age data High mountain chain Rocks?

3. Transform-Fault Boundaries Volcanos dispersed, most on one side Earthquakes complex, shallow (to medium) on both sides Age data not symmetrical, one side of boundary Complex topography, wide mountains and basins Rocks?

Plate Tectonics The upper mechanical layer of Earth (lithosphere) is divided into rigid plates that move away, toward, and along each other Most (!) geologic action occurs at plate boundaries in DISTINCT patterns

What’s Driving Plate Tectonics on Earth?

It’s all about convection and heat (loss)! Vigorous convection drives plate tectonics

 What skills did you use in undertaking this activity?  Historical use …  How might you use it in your classroom?  What might you modify?