What is the term for the process by which oceanic crust sinks beneath another plate?

The process by which oceanic crust sinks beneath another tectonic plate is termed subduction. This occurs at convergent boundaries, where two plates move toward each other. In these scenarios, the denser oceanic crust is forced down into the mantle underneath the lighter continental plate or another oceanic plate.

Subduction plays a significant role in the geology of Earth, leading to the formation of deep ocean trenches, volcanic arcs, and a variety of seismic activity. The sinking oceanic plate melts and may contribute to magma formation, which can lead to volcanic eruptions at the surface. This understanding of plate tectonics is crucial in geology as it helps explain the distribution of earthquakes and volcanoes around the globe.

Other terms in the options provided refer to different geological processes. Rifting involves the splitting and pulling apart of tectonic plates, commonly seen in continental areas. Weathering refers to the breaking down of rocks due to environmental factors, and uplift denotes the process where the Earth's crust is pushed upward, often as a result of tectonic forces but not necessarily involving sinking crust.