Abstract
In deltaic and turbiditic deposits along passive margins, such as the Lower Congo basin on the West African margin, the main deformation is not induced by a regional tectonic stress field but by the increase of the sedimentary load leading to gravitational instabilities. The local stress field in such an environment is drastically influenced by the lithological discontinuities, which can reorientate the principal stresses induced by sedimentary loading. In this paper we document the localization of particular faults, called sedimentary shear zones (SSZ); these are formed along the borders of a sandy channel embedded in more fine-grained sediments, as a function of the lithological contrast. Furthermore we describe the reorientation of the stress field, perpendicular to the channel borders in the channel interior. Examples from 3D seismic lines and field studies in SW Ireland and Tunisia are compared with results from analogue and geomechanical models, leading to an integrated interpretation for the formation of the SSZ.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.