What geological feature is formed by the complete rifting of a continent along two arms?

The geological feature formed by the complete rifting of a continent along two arms is a midocean ridge. When a continent undergoes rifting, it essentially stretches and splits apart, leading to the formation of new oceanic crust as magma from below rises to fill the gap. This process occurs along divergent boundaries in tectonic plates, which is where the midocean ridges are typically found.

As the two rifting arms move away from each other, magma continuously rises to create new seafloor, which contributes to the elevation characteristic of midocean ridges. This geological activity can lead to the formation of underwater mountain ranges that are typically lined with volcanic activity, indicating that the rifting process is still ongoing.

Understanding the formation of midocean ridges is crucial in the study of plate tectonics as these features provide insight into the movement of tectonic plates and the geological processes that shape the Earth’s surface.