Theoretical and experimental estimation of geometric relationship of non-parallel conjugate normal faults

Abstract

Intersecting and crossing conjugate normal faults develop at different scales. Equations of geometric parameters of non-parallel conjugate normal faults can be deduced from their trigonometric relations. Physical models can also be used to verify the theoretical calculations and compared with natural examples. In this study, we have used a theoretical approach to outline some key geometric parameters of conjugate normal faults (intersection angles, plunge of intersection line, and vertical and horizontal distances of the intersection point, etc.) and compared them to equivalent geometric values in scaled analogue models. The comparison shows that theoretical plots used for geometric estimation of conjugate normal faults constrain reasonably the geometric parameters in natural cases. Data from the Lufeng Sag of Pearl River Mouth Basin in the northern part of South China Sea, where conjugate non-parallel basement faults propagate and intersect in cover units are compatible with the theoretical geometric estimation.