A long-lived, sediment-filled graben oriented at a high angle to either a neighbouring modern ocean or a neighbouring orogenic belt; an intracontinental graben (Umeji (1988) Int. J. Earth Scis. 77, 2). An aulacogen can be seen as the failed arm of a triple-limbed spreading centre (Jansen (1975) Trans. Geol. Soc. S. Afr. 78).
Subjects: Earth Sciences and Geography.