Setting the stage:
This exercise is most effective if done after the isostasy activity. The student need to understand the concept of buoyancy. Have a class demonstration of right versus left strike-slip faults. Talk about compressional bends and releasing bends, components found in strike-slip faults that have compressional and extensional aspects. Remember that in the San Andreas Fault, which runs 700 miles through the state of California, all three types of motion can be found.
Go over review questions about crust type as a class.

Exploration/Investigation
Have students work in groups of three to four. They will start with #1 Pish and Pull. On Task #1 they will color the different types of margins on their photocopied 11x17 world tectonic map. There can be one of these per group. You may need to have a mini class discussion about convection cells either during the investigation or in the Setting the stage section. You will be using the shuttle images and the National Geographic Map to determine if the space shuttle photos represent any of these interactive plate margins. The third part, about transform faults may be difficult conceptually for the students, so you may want to complete this as a class and use it as an assessment of how the students understand the large concept.

Bringing it together:
Review right versus left lateral faults and constraining versus releasing bends. Talk about some of the features you would find at constraining and releasing bends.
Class discussion of the answers to Task 3.

Assessment:
World tectonic map colored
Activity sheets completed

Background:
The tectonic plates of the world are constantly moving in relation to each other. The boundaries between plates are zones of active faulting and earthquakes. There are 3 types of plate boundaries and three types of faults. Remember, there are two types of crust which can be involved in this faulting, oceanic crust and continental crust.

CONTINENTAL CRUST VERSUS OCEANIC CRUST

CONTINENTAL CRUST

OCEANIC CRUST

Convergent boundaries occur where plates push together. This is where subduction zones and collision zones are located. The type of faults that form along convergent boundaries are reverse faults, also called thrust faults. Convergence involving oceanic crust results in subduction zones, where the oceanic crust dives back into the mantle. There are two types of subduction zones, one where oceanic crust subducts beneath continental crust and the second where two oceanic plates converge and the older, colder and denser oceanic plate subducts beneath the younger, hotter and more buoyant oceanic plate. Along the first type of subduction zone, a trench forms on the ocean floor where the oceanic plate is being subducted beneath the continental plate. A strato-volcano mountain range is formed on the overriding plate when the oceanic plate is melted and the magma rises to form the volcanoes. When a convergent boundary involves two pieces of continental crust, a collision zone develops as the plates push up large mountains belts such as the Himalayas.

At divergent margins, plates move apart and new crust and lithosphere are created. This usually occurs at a Mid-Ocean Ridge, but divergent margins can also occur on land. The Great Rift Valley of Africa is a example of a divergent margin that is splitting the African continent into two parts. Eventually, as the rift continues to open, a new ocean basin will be formed. Divergent boundaries that occur under continental crust pull pieces apart to form parallel basins and ranges.
Where oceanic plates move apart, magma wells up from the mantle and crystallizes against the trailing edges of the plates. This is how new oceanic lithosphere is formed. Spreading across mid-ocean ridges is symmetrical, and normal faulting predominates. Earthquakes are weak but common. As this new, hot lithosphere cools and moves away from the mid-ocean ridge it isostatically adjusts and settles lower into the mantle, increasing the depth of the sea floor.
Sea floor volcanism and hydrothermal activity are common along Mid-Ocean Ridges.
Magma cooling at mid-ocean ridges continuously records variations in the polarity of the Earth's magnetic field.

Transform faults are associated with convergent and divergent boundaries. A transform fault moves pieces of crust past each other forming a strike-slip fault. This lateral motion can be described as either left-lateral or right-lateral. The way to determine whether a transform fault is left-lateral or right-lateral is to picture yourself standing and looking across the fault. If the land on the other side of the fault moves to your left, it's a left-lateral fault. If the land on the other side of the fault moves to your right, it's a right-lateral fault. Where tectonic plates slide past each other along a strike-slip fault, many strong, shallow earthquakes occur.
In oceanic settings these faults occur between segments of the mid-ocean ridge. Crust of different ages is in contact with one another.
Transform margins also occur in continental lithosphere and can be identified when rocks of different age and composition are in contact with each other. Continental transform faults can cause crustal uplift (mountains) and subsidence (basins) due to local compression and extension. The San Andreas Fault is a notable example of a continental transform fault. Where there is divergence along the San Andreas Fault, the land pulls apart forming a basin. Where there is convergence, the land collides, forming mountains.

Activity Sheets:
Student Activity sheet can be downloaded and printed from HERE.