Exhumación alpina del bloque morfotectónico Pedriza - La Cabrera (Sierra del Guadarrama, Sistema Central Español): potencialidad de la termocronometría por trazas de fisión en apatitos

Abstract

The principles of Apatite Fission Track Analysis (AFTA), which allows to decipher the time-temperature paths of apatites since their last cooling below about 110°C are given and one example, from a Pedriza - La Cabrera block, is discussed. It is suggested from AFTA that the cooling history of this sample followed three steps: from 45 Ma to 35 Ma, slow cooling at a rate of 2,5 - 5° C/Ma between 110° C and 60° C, followed by a quasi-plateau at 70-80°C up to about 70 Ma ago, where a new cooling episode started, with a mean 6 -7 ° C/Ma cooling rate up to the present time