An extensive apatite fission-track study throughout the Northern ApenninesNappe belt

This paper takes into consideration more than 100 apatite fission-track ana lyses on samples coming from an approximately west-east cross-section throu ghout the Northern Apennines. This collisional chain is made of structural units and nappes (Ligurian and Tuscan Nappe) accreted to the Adriatic Forel and during the Neogene, which overthrust the Miocene turbiditic successions of the Cervarola and Mamoso-arenacea Formations. Different cooling ages an d degrees of annealing delineate different evolution histories for these un its. Exhumation of the western outcrops of the Ligurian Nappe can be placed at 8 Ma and follows a first denudation event occurred in Eocene times. Tim ing of exhumation decreases eastwards. A break in this general trend is sho wn by the Apuan Alps, that occupy an intermediate position and yielded the youngest cooling ages. In the external part of the Mamoso-arenacea foredeep deposits this tendency could not be tested because total annealing of the apatite system has not been reached. In this case, modeling of data allows evaluating maximum burial temperatures.