--> ABSTRACT: Multiple Breakout of Experimental Salt Sheets and Related 3-D Fault Systems, by M. P. A. Jackson, H. Ge, and B. C. Vendeville; #91021 (2010)

Datapages, Inc.Print this page

Multiple Breakout of Experimental Salt Sheets and Related 3-D Fault Systems

JACKSON, M. P. A., H. GE,  and B. C. VENDEVILLE

A physical model simulated sub-salt structures created by emplacement and evacuation of several generations of stacked salt sheets driven seaward by episodic progradation. Structural evolution is shown by sequential maps and restored cross sections and compared with examples in the Gulf of Mexico. In each of six cycles, a salt sheet extruded from an emergent diapir, became buried and was squeezed seaward by prograding strata, then broke out again farther seaward. This seaward shift eventually created a multi-tiered salt system that leaned strongly seaward. Additionally, small sheets extruded landward and pooled in the rollover syncline in the front of the prograding wedge. These subsidiary landward-extruding sheets became partially evacuated or entirely welded. Evacuation and local extension created trailing fault systems: normal faults that soled out on the evacuated salt and whose arcuate map traces delineated the outlines of the underlying salt sheet. Evacuation also created keystone fault systems in the stretched crest of rollover anticlines or turtle anticlines. Basal flaps of inverted strata underlay salt sheets, typically just seaward of the inclined feeder stem. Extreme shortening or extension occurred locally, but the overall length of cross sections remained constant. Strains were complexly balanced by a combination of (a) space-creating deformation such as normal faulting, salt evacuation, and roof dismemberment versus (b) space-filling deformation such as buckling, active diapirism, fold-nappe rolling, roof overthrusting, and salt breakout and extrusion.

AAPG Search and Discovery Article #91021©1997 AAPG Annual Convention, Dallas, Texas.