Dismembered Sutures Formed During Asymmetric Salt-Sheet Collision

Tim P. Dooley, Michael R. Hudec, and Martin P. Jackson
Bureau of Economic Geology, The University of Texas at Austin, Austin, TX

Salt canopies amalgamate by suturing of individual salt sheets. In our physical models, upright sutures form if the sheet collision is symmetric. However the sutures become progressively more asymmetric as one sheet overrides the other. The weight of the overriding sheet expels salt in the lower sheet away from the collision zone, deforming the intervening sediments into the concave-up form characteristic of many sutures. Continued advance of the overriding sheet may bulldoze this suture, dismembering it and translating the pieces far from the original point of collision. Thus the common assumption that intrasalt reflections mark the collision point between salt sheets may be incorrect if there has been significant override.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas