Young and tectonically active mountain chains like Central Apennines (Italy), characterized by a high structural complexity, represent astonishing examples for making strong inferences on seismotectonics. Repeated cycles of tectonic phases recognized by surface geology result in the development of a series of interacting fault systems as well as in a widespread reactivation of inherited structures, usually disarticulating pre-existing tectonic arrangements. In this context, what is observable at surface might mask a different structural architecture at depth, where shallow structures may be decoupled from the deeper ones. In the last decades, Central Apennines have been affected by a complex pattern of seismicity, which has been associated to the activation of both single faults and complex fault systems. Within the framework of the RETRACE-3D project, we reviewed a large set of underground data acquired for hydrocarbons explorations in the area struck by the 2016-2018 Central Apennines seismic sequence. Main goal is to build a comprehensive 3D geological model able to match the superficial observations with the deeper ones, and with the recent seismicity. Although the current extensional tectonic regime, results primarily show that the main architecture of this portion of the chain is still dominated by previous compressional large-scale structures, widespread evidence of segmentation, reactivation and even inversion of various sets of inherited faults. A reliable 3D geological modelling down to seismogenic depths as well as the recognition of reactivated paleo-structures play a fundamental role in understanding the seismotectonics of the considered area, also allowing to more robustly infer on the seismogenic potential of faults. This work would also open new points of discussion regarding information and input data needed to improve the assessment of seismic hazard in mountain chains such as the Central Apennines.
The shallow crustal setting of the Central Apennines in the 2016-2018 seismic sequence area: fault segmentation, interaction, reactivation and implication for seismotectonics
Petracchini L;Scrocca D;Cavinato G;
2019
Abstract
Young and tectonically active mountain chains like Central Apennines (Italy), characterized by a high structural complexity, represent astonishing examples for making strong inferences on seismotectonics. Repeated cycles of tectonic phases recognized by surface geology result in the development of a series of interacting fault systems as well as in a widespread reactivation of inherited structures, usually disarticulating pre-existing tectonic arrangements. In this context, what is observable at surface might mask a different structural architecture at depth, where shallow structures may be decoupled from the deeper ones. In the last decades, Central Apennines have been affected by a complex pattern of seismicity, which has been associated to the activation of both single faults and complex fault systems. Within the framework of the RETRACE-3D project, we reviewed a large set of underground data acquired for hydrocarbons explorations in the area struck by the 2016-2018 Central Apennines seismic sequence. Main goal is to build a comprehensive 3D geological model able to match the superficial observations with the deeper ones, and with the recent seismicity. Although the current extensional tectonic regime, results primarily show that the main architecture of this portion of the chain is still dominated by previous compressional large-scale structures, widespread evidence of segmentation, reactivation and even inversion of various sets of inherited faults. A reliable 3D geological modelling down to seismogenic depths as well as the recognition of reactivated paleo-structures play a fundamental role in understanding the seismotectonics of the considered area, also allowing to more robustly infer on the seismogenic potential of faults. This work would also open new points of discussion regarding information and input data needed to improve the assessment of seismic hazard in mountain chains such as the Central Apennines.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
