The Development of Inverted Faults: Results from Analogue Plaster Models

Ivar Grunnaleite
IRIS (Int. Research Inst. of Stavanger), N5008 Bergen, Norway

The geometry of four plaster cast experiments of positive inversion were carefully analysed during intermediate stages of deformation. Positive structural inversion relates to deformation of structures initiated during extension by a later phase of compression. The experiments were chosen to show variation in fault geometry, from simple planar faults to arrays of synthetic, listric- and planar-, faults and complex deformation zones consisting of interconnected blind faults and extensive- and compressional duplexes. The analyses comprised observations of structural evolution, variations of area and lengths, displacement, dip of horizons and faults, block deformation and shear angles during deformation. The analysis is summarized in a general five-stage evolution of inversion structures: 1) Early extension stage, 2) Extensional faulting stage, 3) Early inversion stage, 4) Reverse faulting stage and 5) Thrusting stage. Such detailed analyses of inverted faults may increase the understanding of inversion and help identify such structures in field and on seismic data and understand their evolution history.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece