A point where three lithosphere plate boundaries intersect.
three fractures in the lithosphere which meet at roughly 120o angles on a map. They form during the initial stages of continental rifting. Grabens usually form along the fracture patterns. As rifting continues, two of the three "arms" of the triple junction continue to widen, perhaps creating a new ocean basin be-tween the separating continental chunks, while the third one "fails" (an aulocogen).
A point that is common to three plate and which must also be the meeting place of three boundary features, such as divergence zones, convergence zones, or transform fault.