The moving tectonic plates are the reason for different geologic features like faults, earthquakes, volcanoes, mountains, ocean basins and the origin of the continents at Earth's surface. Depending on the nature of the plate interaction and of the margins, different types of geologic activities occur.
Explanation:
The Earth's crust is divided into several hard and rigid tectonic plates that slide over the mantle. Crust is the thin outer portion of the planet. Mantle is the thick, dense layer of rock underneath the crust, which is solid near the top and partially melted beneath the surface. The lithosphere includes the crust and outer rigid portion of the mantle, the partially melted portion of the mantle is called the asthenosphere.  Lithosphere is broken up into plates (eight major plates and several smaller ones), which move around while floating upon the asthenosphere lying underneath. These plates have different shapes and sizes. They are in constant contact with each other so the movement of one plate causes the other plates to move. The major geologic features like faults, earthquakes, volcanoes, mountains, ocean basins and the origin of the continents at Earth's surface are due to the  movement of these plates toward or away from each other.
Tectonic plates can interact in three different ways : converge (move toward one another), diverge (move away from one another) or transform (slide past one another). The plate margins are the boundaries where plates meet and they are of three kinds: oceanic-oceanic, continental-continental, and continental-oceanic. Â Depending on the nature of the plate interaction and of the margins, different types of geologic activities occur.
Oceanic-oceanic plates: when two oceanic plates converge, one of the plates sinks underneath the other and forms a deep depression called ocean trench. The plate sinks further downward into the mantle and begins to melt. From the melting plate, molten rock rises toward the surface and forms a chain of volcanic islands behind the ocean trench. When oceanic plates diverge, a mountain chain (ridge) develops and seafloor spreading occurs. Molten rock rises toward the divergent margin, creating mountains and an expanding seafloor.
Continental-continental plates: when two continental plates converge, they buckle and compress to form complex mountains ranges of great height. Example is the Himalayas, which is formed when the Indian-Australian plate collided with the Eurasian plate. Â When two continental plates diverge, a continent is ripped apart into two or more smaller continental crust they begin to moving apart slowly and magma pushes into the rift formed between them and eventually a new sea is born between the two continents. Example is the Red Sea which is formed by the rifting between the Arabian and African plates.
Continental-oceanic plates: During the convergence of continental and oceanic plates, the denser oceanic plate sinks below the continental plate and a chain of volcanoes known as a volcanic arc are formed. The examples of volcanic arcs are the Cascade Mountains of North America and the Andes Mountains of South America. Continental-oceanic divergent margins do not exist.
When transform motion occurs, two rock plates slide past one another at a margin and a crack or fault develops. As a result, an earthquake occurs due to the energy generated by this movement. The San Andreas Fault in California, where the Pacific and North American plates are in contact is an example of a transform plate margin.
