How Do Plate Tectonics Affect Sedimentation?

Tectonic processes create new sediments as plates collide, move sediment as one plate slips past or overrides another, and ultimately transform sediment by accumulation or volcanic activity. Ocean sediments transfigure based on their location after they interact with tectonic plates.

Subduction occurs when two tectonic plates collide at their convergent boundary, forcing one plate to descend and pulling the other plate over. If the descending plate angles down, it creates a trench into which it carries sediment. As the sediment heats, it dissolves into water, which rises until it reaches the bottom of the upper plate. The pressure as the blocked mixture tries to ascend further causes a phenomenon known as a subduction factory, which uses faults in the plate to create volcanic and tectonic activity.

The upper plate scrapes sediment from the descending plate as it passes over. If the subduction occurs along a transform plate boundary as the result of sideways slipping, the sediment moves parallel to the edge until it reaches an obstacle and builds up into a wedge. Additional tectonic activity disperses sediment further away from the obstacle.

Plate tectonic processes create massive changes in geological time frames. They can result in cataclysmic events in very short time frames, including earthquakes, volcanic eruptions and tsunamis.