Final answer:
Subduction leads to the melting of the subducted plate, forming magma which rises to solidify as igneous rock. Uplift exposes deep, intrusive igneous rocks and forms mountain ranges where ophiolite complexes can occur. These geological processes are essential for creating the diversity of igneous rocks found in the Earth's crust.
Step-by-step explanation:
Subduction and uplift are geological processes that play a critical role in the formation of igneous rock. Subduction occurs when one tectonic plate moves under another into the mantle, typically an oceanic plate moving under a continental plate. The process of subduction leads to the creation of magma as the subducting plate melts due to high temperatures and pressures deep within the Earth. This magma can then rise to the surface and solidify to form extrusive igneous rock or cool slowly beneath the surface to become intrusive igneous rock.
Uplift accompanies subduction, especially when two continental plates collide. During this process, the oceanic lithosphere, which can consist of ultramafic and mafic rocks, is exposed and uplifted, often forming mountains. These sequences of igneous rocks, mafic to ultramafic, can be found in ophiolite complexes in mountainous regions. Uplift not only brings deeper rocks to the surface but can also contribute to the exposure of intrusive igneous rocks, such as granite, that formed well below the Earth's surface.
The formation of igneous rock via subduction can occur in various ways. For instance, water released from hydrated minerals in the subducting oceanic crust can lower the melting point of the overlying mantle. As a result, magma is generated, which can lead to volcanic eruptions or, if the magma cools slowly beneath the surface, the formation of intrusive igneous rock such as gabbro or granite depending on the mineral composition.