Ioannis Zervas

Past Research

Strike-slip growth, interaction, rotation and reactivation above weaknesses zones: Levant Basin, offshore Israel

Fault growth and interactions are of high importance since they are key elements for understanding the structural evolution of the basin, hydrocarbon-related fault migration pathways and reservoir properties. However, strike-slip growth and interaction studies are limited by the difficulty of evaluating the slip along the fault plane. The post-Messinian fine layered interval, deposited above thick ductile salt, is used to understand the structural evolution, growth and interactions of domino and conjugate pairs of naturally occurring predominantly strike-slip faults in the Levant Basin. Detailed fault and horizon interpretation, followed by seismic attribute analysis, thickness maps and spectral decomposition are the prerequisite steps to conduct conventional fault growth analysis. An abundance of avulsion channel packages derived from the Nile Cone have been used as piercing markers (good spacing of measurements) to evaluate the variations of the horizontal slip in each point(s) of fault segments. Moreover this research is divided into three parts.

The first one entails major fault analysis and uses: i) displacement-distance plots to evaluate segmentation and displacement transfer due to fault interaction, ii) spatial projection of displacement along the entire fault plane to evaluate segment linkage, propagation and nucleation, iii) intends to introduce a new methodological approach of predominantly strike-slip faults, with the conduction of dip-versus strike-slip plots (D-S) that can provide relationships between the two components and differentiate simultaneous slip from reactivated.

The second part focuses on the examination of trans-rotational basins of sub-parallel faults and rotation form a single fault. The main purpose is to understand mechanically and kinematically how rotation occurs in such regimes. A secondary target is spatial examination of rotation with nucleation points and identification of the axis of rotation from the seismic data.

Lastly, the kinematic history of active faults that intersect at an angle and create conjugate pair of faults is still debatable. Several researchers have considered that slip occurs synchronously on crossing conjugate faults and faults terminate without offsetting each other. Conversely, geometrical problems arise on a simultaneous slip, requiring volume loss or gain at the intersection area. To eliminate compatibility geometrical space problems some researchers suggested a sequential fault intersection where newer formed faults offset earlier faults. However, when a fault offsets another fault, the latter is likely no longer activated. Apart from this, conjugate pair of faults can be either developed from fault bifurcation or splays. Therefore, the last part entails the analysis of the kinematics of conjugate strike-slip faults to address the aforementioned kinematic problem and examine the associated deformation at their triple junctions in the Levant Basin.