The plate boundaries at which lithospheric plates move toward, past, or away from each other are called Convergent, Transform, and Divergent boundaries, respectively.
Earth's lithosphere, its rigid outer shell, is broken into large slabs known as tectonic plates. These plates are constantly in motion, albeit very slowly. The interactions between these moving plates occur at their edges, which are called plate boundaries. The type of boundary is defined by the direction in which the plates are moving relative to each other.
Types of Plate Tectonic Boundaries
Based on the relative movement of the lithospheric plates, there are three primary types of plate boundaries:
a. Plates Move Toward Each Other: Convergent Boundaries
When two lithospheric plates move towards each other, they form a convergent boundary. The outcome of a convergent boundary depends on the type of crust involved (oceanic or continental). According to Study.com's information, results include subduction (where one plate dives beneath another) or collision.
Key characteristics of Convergent Boundaries:
- Movement: Plates move toward each other.
- Results: Subduction or collision.
- Landforms Created: Volcanos, mountains, islands, oceanic trenches.
- Example: The Himalaya mountains are a famous example of a convergent boundary where two continental plates collided.
b. Plates Move Past Each Other: Transform Boundaries
At a transform boundary, lithospheric plates slide past each other horizontally. Unlike convergent or divergent boundaries, crust is neither created nor destroyed at transform boundaries.
Key characteristics of Transform Boundaries:
- Movement: Plates slide past each other horizontally.
- Results: Earthquakes are common due to the friction and stress built up as the plates grind against each other.
- Landforms Created: Often marked by faults and sometimes linear valleys or ridges.
- Example: The San Andreas Fault in California is a well-known transform boundary.
c. Plates Move Away From Each Other: Divergent Boundaries
When two lithospheric plates move away from each other, a divergent boundary is formed. At these boundaries, new crust is generated as magma from the mantle rises to the surface and solidifies. According to Study.com's information, the result is spreading.
Key characteristics of Divergent Boundaries:
- Movement: Plates move away from each other.
- Results: Spreading, creation of new oceanic crust.
- Landforms Created: Volcanos, mountains (specifically mid-ocean ridges), new crust.
- Example: The Mid Atlantic Ridge is a prime example of a divergent boundary in the Atlantic Ocean.
Summary Table
Here's a summary based on information found in the Study.com reference, including details for all three boundary types for clarity:
| Characteristic | Convergent | Divergent | Transform |
|---|---|---|---|
| Movement of plates | Towards each other | Away from each other | Past each other |
| Results | Subduction or collision | Spreading | Earthquakes |
| Landforms created | Volcanos, mountains, islands, oceanic trenches | Volcanos, mountains, new crust | Faults, offset features |
| Example | Himalaya mountains | Mid Atlantic Ridge | San Andreas Fault |
Understanding these different types of boundaries is crucial for comprehending many geological phenomena, such as earthquakes, volcanic activity, and mountain formation.
