Final answer:
A terran is a fragment of the lithosphere bounded by faults, transported by plate tectonic movements, and may converge with another plate. Plate tectonics involves the movement of Earth's plates through convection in the mantle, leading to geological features like mountains and subduction zones.
Step-by-step explanation:
The structure being described is known as a terran or terrene. A terran is a small to medium mass of the lithosphere, surrounded by faults, which may be transported long distances by the movement of tectonic plates until it converges with the edge of another plate. Lithospheric plates can move in several directions with varying speeds and create features such as mountains and trenches through mechanisms like subduction, where one plate descends beneath another.
Plate tectonics is the theory that describes these slow movements within Earth's mantle, driving the plates apart at divergent boundaries, together at convergent boundaries, and sliding past each other at transform boundaries. The motions of these plates are fueled by the convection currents within the mantle due to the temperature differences between the hot interior and cooler mantle.
The concept of plate tectonics is crucial to understanding the geologic process that shapes our planet. It operates as a planetary cooling system, allowing Earth to efficiently transfer interior heat to space. As the plates move, they carry continents and oceanic crust along, leading to dynamic changes in the Earth's surface over geological time scales.