Displacement analysis of basin-scale reactivated normal faults

Abstract

Displacement-distance diagrams are valuable for studying fault interactions and growth. Examples of displacement patterns for faults that underwent multiple reactivation events are limited. This study presents along-strike and along-dip displacement-distance diagrams for nine basin-scale faults from the West Netherlands Basin, which has experienced multiple phases of displacement. The diagrams were derived from 3D seismic reflection data, covering 2300 km 2 and 6 km in depth. Due to the dataset size, we developed a semi-automated workflow to map faults, reduce noise, and generate displacement-distance diagrams. To determine the effects of both multiphase rifting and transpressive basin inversion on fault growth, we studied four faults only recording extensional events and five faults that also experienced inversion. We observed distinctive along-dip displacement patterns, characterized by piecewise curves, identifying pre-, syn-, and post-rift phases of fault growth, as well for a later inversion event. The shape of lateral displacement patterns suggests quasi-fixed lateral fault tips throughout the fault’s history and faults developing their lateral lengths early, with later reactivation mainly increasing their vertical extent while accumulating displacement. In addition to improving our understanding of how faults grow through multiple reactivations, these results may provide insights into the growth-history of faults in other inverted rift basins world-wide.