Remarks on a Deep Crustal Section Across the Northern Apennines, Italy

Abstract

The crustal setting of the northern Apennines is outlined by a key crustal section cutting across the Apuan Alps metamorphic core complex, Tuscan and Ligurian nappes and the Padana buried belt, prepared using available geological and geophysical data, and made consistent with an extensional tectonic model. The key section was prepared keeping in mind that the northern Apennines resulted from the interaction of compression and extensional tectonics, which migrated from west to east as out-of-phase pulses. Data interpretation pointed out some problem areas that to be addressed to match the geological and geophysical data with the extensional tectonics models. The problem areas include: a) the geometry of the normal faults which fragment the compressive structures of the northern Apennines at depth in order to determine which extensional models relate the normal faults to the crustal extension; b) the seismic reflectivity or transparency of deep crustal shear-zones, and the role they play in compressional and extensional tectonics; c) the nature and meaning of the crust-mantle transition in the inner side of the mountain belt where a melting occurs; d) what the random deep reflectors with Vp = 8 km/s in the inner side of the mountain belt, below the anomalous crustal-mantle transition represents. In drawing the key crust section geometric constraints required us to develop a solution to each it these problem areas; therefore the key section not only represents a summary of the available data but also an interpretation of the deep crustal tectonics of the northern Apennines.KeywordsNormal FaultGeophysical DataCrustal StructureThrust BeltSeismic RefractionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.