The point where three lithospheric plates meet. This junction may involve three oceanic ridges (an ‘RRR’ junction), thought to have developed from a domal uplift; or involve some other configuration of ridge (‘R’), transform fault (‘F’), and oceanic trench (‘T’). Some types of triple junction are stable, while others evolve geologically rapidly into a different configuration. An example of an RRR junction is the point where the African, South American, and Antarctic Plates meet in the S. Atlantic.