1. Divergent Boundaries:
* Definition: These boundaries occur where two tectonic plates move apart.
* Features:
* Mid-ocean ridges: Underwater mountain ranges formed by magma rising from the mantle and solidifying.
* Rift valleys: Deep valleys formed on land as the crust is pulled apart.
* Volcanic activity: Frequent volcanic eruptions as magma rises from the mantle.
* Earthquakes: Shallow earthquakes are common.
* Example: The Mid-Atlantic Ridge, the East African Rift Valley.
2. Convergent Boundaries:
* Definition: These boundaries occur where two tectonic plates collide.
* Features:
* Subduction zones: One plate slides beneath the other (the denser plate sinks).
* Ocean trenches: Deep depressions in the ocean floor formed where the subducting plate bends.
* Volcanic arcs: Chains of volcanoes formed on the overriding plate.
* Mountain ranges: Large mountain ranges can be formed where two continental plates collide.
* Earthquakes: Deep and powerful earthquakes are common.
* Types of Convergent Boundaries:
* Oceanic-continental: Oceanic plate subducts under a continental plate.
* Oceanic-oceanic: One oceanic plate subducts under another.
* Continental-continental: Two continental plates collide.
* Example: The Andes Mountains (oceanic-continental), the Mariana Trench (oceanic-oceanic), the Himalayas (continental-continental).
3. Transform Boundaries:
* Definition: These boundaries occur where two tectonic plates slide past each other horizontally.
* Features:
* Fault zones: Fractures in the Earth's crust where the plates move past each other.
* Earthquakes: Frequent and sometimes powerful earthquakes.
* Limited volcanic activity: Volcanic activity is less common at transform boundaries.
* Example: The San Andreas Fault in California.
Understanding the interactions between these different types of plate boundaries is crucial for understanding a wide range of geological processes, including mountain formation, volcanic eruptions, and earthquakes.
