Distribution of joints in the hinge-line culmination of foreland-verging overturned anticlines: an example from the Montagna dei Fiori structure in the Central Apennines of Italy

Abstract

AbstractThe distribution of joints, veins and shear fractures in the Montagna dei Fiori overturned anticline is here reported. Two joint sets, longitudinal and transverse to the NNW–SSE anticline axial trend, and a conjugate system of shear fractures, are recognized. The transverse and longitudinal joint sets have a pre-folding development likely related to the foreland/foredeep flexure. The transverse joints were reopened during layer-parallel shortening along with the development of the shear fractures. Then, during syn-folding outer-arc extension and hinge-line culmination fold-axial parallel extension, both the longitudinal and transverse joints were enhanced and reactivated, respectively.