Kinematics of the propagation and growth of normal faults: implication for petroleum geology 

Catherine Baudon, 3D Lab, Earth, Ocean and Planetary Sciences department, Cardiff University, Wales, U.K., [email protected]

Detailed fieldwork and recent improvements in both numerical studies and seismic data have led to the development of several different models for the kinematic evolution (initiation, propagation, linkage) of normal faults that can be divided into two general categories. One suggests that a single isolated fault grows by radial propagation in a scale-invariant manner as the slip increases, with no migration of the point of nucleation. The second model explains the growth of faults by linkage of initially isolated faults that propagate towards each other, overlap and subsequently link.

This project aims to test these models and understand the mechanics and kinematics of fault growth in a range of different structural and depositional contexts.

In order to address this problem, geometrical and displacement analysis have been carried out using 3D seismic datasets from the offshore Nile Delta (Egypt) and on the Levant basin (offshore Israel). The analysis of faults in a range of structural contexts allows us to assess the fault geometry and length, fault zone thickness, throw, tip gradients and gross morphology of linkage structures. A simple geometrical approach based on expansion index, cumulative and incremental throw was used to define the fault growth histories.

A field analogue study carried out on small-scale relay structures located in the Canyonlands National Park, S.E. Utah provided linkage characteristics (geometry, kinematic and strain distribution) that are integrated with high resolution 3D data. This enabled the development of a model for the growth, propagation and linkage of normal faults.