Mechanical Heterogeneity and the Prediction of Fault Zone Architecture - Outcrop Examples and Models

The RDR Fault Foundation project, an industry-funded consortium research project, has studied the development of complex fault zone architecture using a combination of outcrop mapping and numerical modelling, with the aim of predicting the likely geometry and fluid flow properties of subsurface faults. The key controls on fault zone architecture are the throw on the fault and the mechanical heterogeneity – fault zones are likely to be wider and more complex where there is a strong contrast in mechanical properties between layers. However this contrast is not only a function of lithology, but is also affected by burial history. In this paper we present kinematic models to predict the development and distribution of three key elements in fault zone architecture: clay smears, fault gouge and fault-bound lenses. We compare the results of these models with outcrop examples from Utah and Sinai, Egypt.