Structural setting at the front of a thrust and fold belt: the Craco area (Southern Apennines, Italy)

The Craco area displays some of the best outcrops of the frontal part of the Southern Apennines; it is therefore a key area for interpreting the evolution of a recent thrust belt. This paper reports the results of detailed geological mapping, accompanied by structural interpretations and biostratigraphic analyses. Geological mapping shows that the Craco area is characterised by laterally discontinuous contractional structures that include thrusts, backthrusts and folds. Steeply-dipping faults, striking N-S to N50E, offset the contractional structures. We propose an evolutionary scheme based on evidence on synsedimentary tectonics and biostratigraphy. The first tectonic stage (Early Pliocene) is documented by the onlap pattern of the Early-Late Pliocene succession (second cycle) on the Early Pliocene sediments (first cycle). Afterwards (Late Pliocene-Early Pleistocene), the Pliocene strata were steepened by the activation of backthrusts. This is displayed by the general attitude of the second cycle deposits, which dip of 23-30 degrees towards the NNE. In the south-western portion of the area movements along backthrusts follow intense thrusting and folding of the first cycle succession.