lemezsubdukció

Lemezszubdukció is a fundamental geological process where one tectonic plate slides beneath another and sinks into the Earth's mantle. This occurs at convergent plate boundaries, typically where an oceanic plate meets a continental plate or where two oceanic plates collide. The denser plate, usually the older and colder oceanic plate, is forced downwards under the less dense plate.

As the subducting plate descends, it experiences increasing temperature and pressure. This leads to the release of water trapped within the minerals of the oceanic crust. This water lowers the melting point of the overlying mantle wedge, causing it to partially melt and form magma. This magma, being less dense than the surrounding rock, rises towards the surface.

The rising magma can erupt, forming volcanoes. If subduction occurs at an oceanic-continental boundary, a volcanic mountain range often forms along the edge of the continent, such as the Andes. If it occurs at an oceanic-oceanic boundary, a chain of volcanic islands, known as an island arc, is created, like the Mariana Islands.

Subduction zones are also responsible for generating powerful earthquakes, as the two plates grind against each other. The deepest earthquakes occur in subduction zones. The process of lemezszubdukció plays a crucial role in plate tectonics, driving the recycling of Earth's crust and shaping the planet's surface over geological timescales.