Vergence (geology)

In geology, vergence denotes the tilting direction of inclined folds . For example, a fold inclined to the east is called east vergent .

The angle that the axial surface forms with the vertical is called the vergence angle or degree of vergence .

Folds with opposite vergence in a fold package or fold mountains have divergence when the axial surfaces form an upwardly open fan, and antivergence when they form a downwardly open fan. The boundary between fold parts of different vergence is called the vertex line or vertex .