Intrasalt Structure And Strain Partitioning In Layered Evaporites: Insights From The Messinian Salt In The Eastern Mediterranean

Abstract

The evaporite-dominated Messinian sequence is lithologically heterogeneous as halite is interbedded with other salts, in addition to clastics or carbonates. This lithological heterogeneity can lead to rheological heterogeneity, and the different mechanical properties of the various rock types controlling strain partitioning within deforming evaporites. Determining the composition and internal structure of salt bodies is important for safe drilling through thick salt sequences, and enables us to build better velocity models that allow more accurate seismic imaging of subsalt geology. However, due to typically poor seismic imaging, and a lack of outcrop and well data, the nature of this lithological control on intrasalt deformation is poorly understood. We use high-quality 2D and 3D seismic reflection data to map intrasalt structural style, and horizontal and vertical variations in strain. This enables us to determine how lithological and thus mechanical heterogeneity affects the structural evolution of the salt during early stage salt tectonics.