Plate Tectonics Questions Medium
The process of back-arc basin formation occurs at subduction zones, where one tectonic plate is forced beneath another. When an oceanic plate subducts beneath a continental plate, the subduction process creates a trench on the oceanic plate side. As the oceanic plate sinks deeper into the mantle, the overlying continental plate is stretched and thinned, leading to the formation of a back-arc basin behind the volcanic arc.
The stretching and thinning of the continental plate create a region of tensional forces, causing the lithosphere to break and form a basin. This basin is often filled with sediment and can be characterized by a series of fault systems and volcanic activity. The volcanic activity in the back-arc basin is typically less intense compared to the volcanic arc on the other side of the subduction zone.
The formation of a back-arc basin is influenced by various factors, including the angle of subduction, the rate of subduction, and the composition of the subducting plate. These factors can affect the width, depth, and overall development of the back-arc basin.
Overall, the process of back-arc basin formation is a result of the complex interactions between tectonic plates at subduction zones, leading to the creation of a distinct geological feature behind the volcanic arc.