Exhumation and reshaping of far-travelled/allochthonous tectonic units in mountain belts. New insights for the relationships between shortening and coeval extension in the western Northern Apennines (Italy)

摘要: Abstract Coeval extensional and contractional tectonics are a common feature in orogenic belts, especially post-collisional phases. The attempt to constrain their relative timing the responsible mechanisms led several models taking into account different geodynamic contexts of various mountain chains. In peri-Mediterranean collisional orogens, extension compression commonly associated coeval emplacement far-travelled/allochthonous units. Therefore internal deformation acquired during translation across belts is likely imprinted by affecting orogen. western portion Northern Apennines Italy, one northernmost Tertiary units, i.e., Ligurian Subligurian widely exposed. present study integrates published newly surface geological data (geological maps, cross-sections), subsurface boreholes data, paleothermal (vitrinite reflectance, mixed layer illite–smectite Kubler index) thermochronological (apatite fission-tracks) order investigate history and, consequently, record extension–compression relationships within these modes reshaping units allowed us strengthen hypothesis that were tightly connected cause/effect relationship. particular, late low- high-angle represent response an overall regime which induced episodes gravitational instability wedge.