1. Explain the differences between divergent, convergent, and transform plate boundaries.
2. Describe the land features associated with each type of plate boundary.
3. Give examples of land structures found at each plate boundary.
4. Discuss the formation and breakup of Pangaea including the mechanism and the approximate time of its breakup.
All around the Earth the topography of the continents is undergoing constant change. We are reminded daily by the occurrence of earthquakes and the occasional eruption of volcanoes. The change is due to the movements of tectonic plates and the boundaries between them. There are three major types of boundaries. Each is classified according to the type of movement.Plate Boundaries
|Associated with plate boundaries|
|Seismic activities (earthquakes)|
|Rift valley formation|
(www.creationscience.com/.../ mid-atlantic%20ridge%203.jpg) (www.creationscience.com/.../ painted%20mid-ocean%20ridge.jpg)
|Formed when two plates are moving towards each other|
|Sets up subduction boundaries|
|Oceanic – Oceanic boundaries|
|Often forms volcanoes|
|Island arcs form as volcanoes emerge|
|Continental – Oceanic boundaries|
|Forms a subduction zones with a deep ocean trench|
|More dense oceanic plate dives under the less dense continental plate|
|Volcanic arcs (mountain ranges) form|
|Continental – Continental (collision) boundaries|
|Does not always form a subduction zone|
|Can produce mountains|
|Plates slide past one another|
|No new crust is created|
|No crust is destroyed|
Transform faults - San Andreas
|Most are in oceanic crust|
and Breakup of Pangaea
Although no one can be certain how long Pangaea was together most data supports that 250 million years the Earth consisted as one super continent called Pangaea. Since the oldest rocks on the Earth's floor are around 200 million years old, most scientists believe that the continent began to break up at that time.
began about 200 million years ago|
and Africa separated between 200 and 165 million years ago|
and S.America separated about 135 million years ago|