Publication Date:
2023-05-25
Description:
The development of structurally controlled basins is frequently dominated by inherited geological and tectonic structures, especially when the affected region has undergone multiple tectonic phases. In this study we use physically scaled analog models to analyze the impact of inherited faults on the evolution of a new extensional fault system and its associated basin. In our experiments, we introduced inherited faults – bearing diverse geometries and orientations – cut through a homogeneous analog material (wet clay). After each experiment, we compare (a) how the inherited faults affected the inception and development of new faults and (b) the shape of the resulting basins, using a ‘reference model’ run without pre-existing faults. The results show that the orientation of pre-existing faults with respect to the extensional axis does affect the development of the new extensional structures. The main effects show up when the orientation of the pre-existing faults is closer to that expected for a fault that is optimally oriented (perpendicular) with respect to the direction of extension and has a dip close to an Andersonian extensional fault. Conversely, the impact on the resulting basin shape is more spatially complex, especially in the case of misoriented pre-existing faults. We also compare our experimental results with an analytical method based on the slip tendency theory. The application of our findings to selected natural cases demonstrates how one may interpret the occurrence, orientation, and activity of inherited faults by looking at the present-day geometry and wavelength of an extensional basin, particularly when newly formed extensional faults exhibit structurally unexpected trajectories.
Description:
Part of this work was funded by the project “The impact of an inherited structural setting on the development of extensional systems in the Amatrice-Norcia-Visso area: insights from analog modeling” (UR 0865.050; P.I.: Umberto Fracassi), part of the INGV-FISR 2016 Project - Italia centrale “Centro di studio e monitoraggio dei rischi naturali dell'Italia centrale” (cod. D82F16001180001), and by the INGV “FASTMIT” Project (UR 0850.010; P.I.: Roberto Basili – cod. D52F16001150001).
Description:
Published
Description:
104836
Description:
2T. Deformazione crostale attiva
Description:
JCR Journal
Keywords:
Inherited faults
;
Extensional basins
;
Analog modeling
;
Wet clay models
;
Pre-existing faults
;
Fault interaction
;
Fault inversion
;
04.06. Seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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