Dissertation (MSc. Petroleum Geosciences)
There is poor understanding of geometry and evolution of the accommodation zones along the restraining and releasing bends in strike slip systems. This dissertation focused on characterize the accommodation zones between restraining and releasing bends, with special focus on the influences of syn-kinematic sedimentation and the basement pre-existing structuration by simulating the Seagap fault , Off-shore Tanzania.
A set of three scaled sand models were performed, using a basement offset 6.5cm /3cm, 90/90 and 156/126 Stepovers without/with Syn-sedimentation respectively. 7 cm of sinistral displacement was applied during all the models. Vertical sections of the completed models cut for analysis of structures at depth. The experimental results for both models were generating pop-up and pull-apart structures and dip flipping of high angle faults. Study concluded that, firstly comparisons between models and area of study fault orientation and distribution were compatible with a sinistral strike-slip system. The internal structures developed were influenced by syn-sedimentation and pre-existence basement. Even more, oblique accommodation and dip-direction flipping of the main fault produced clear inversion of the structures along the accommodation zones which can potentially have a strong impact on the petroleum system. Future study required a test of different scenarios such as use of ductile basement transition, constrains on fault timing, uplift rate along time and comparison between sandbox analogue models and seismic interpretation.