Tectonostratigraphic analysis of the western Huincul High (Neuquén Basin). Implications for geometry, kinematics and mechanics of inversion systems.

Basin inversion is defined as the compressional and transpressional reactivation and shortening of a formerly extensional basin. This is a common phenomenon that has af- fected sedimentary basins within various tectonic environments including foreland, intracratonic and rifted basins. Inversion systems have been the focus of hydrocarbon exploration for the last three decades, and with the ensuing of the energy transition, inversion structure have the potential to play a crucial role for trapping of carbon dioxide in Carbon Capture Storage projects. The controls that are thought to influence inversion systems are multiple, including architecture of pre-existing extensional structures as well as orientation and mag- nitude of compressional stresses.
This research presents a case study of the Neuquén basin (Argentina) to understand the geometry, kinematics, and mechanics of inversion systems. Emphasis is on the understanding of the tectonostratigraphic evolution of the basin and related mechanisms controlling inversion systems, particularly the morphology of the basement structure, the role of mechanically distinct units involved in inversion and overprinting of reactivated structures due to post inversion tectonics.
The Neuquén Basin is a major Mesozoic sedimentary depocenter located in the foreland of the Andes Mountains with world renown inversion systems. The Huincul High is a structurally and economically prominent c.a. 270 𝑘𝑚 long, E-W trending feature that formed by the accretion of exotic Palaeozoic terranes influencing subsequent Mesozoic deformation in the basin. With this research, for the first time, a set of four 3D seismic reflection surveys covering an area of 1300 𝑘𝑚2 have been analysed and integrated with stratigraphic information from 11 exploratory wells to provide new insights into the tectonostratigraphic evolution of the western reaches of the Huincul High. Section restorations were used to develop and validate the proposed evolutionary pathways. Furthermore, seismic attribute analysis was implemented to understand secondary deformation and development of sedimentation patterns within the basin during pre and syn inversion phases.
The key findings of the research highlight the importance of controls on inversion systems including structural inheritance in the form of segmentation and orientation of existing faults; basement morphology, especially the presence of inherited large scale structures; and mechanical stratigraphy of the syn-extensional sequence. These controls affect both kinematics of inversion and resulting structures which ultimately inform about the potential utilisation of these systems for the energy transition.