RT Journal Article T1 Long-term thermo-tectonic evolution of the Montes de Toledo area(Central Hercynian Belt, Spain): constraints from apatite fission-trackanalysis A1 Barbero González, Luis C. A1 Glasmacher, U. A. A1 Villaseca González, Carlos A1 López García, José Ángel A1 Martín Romera, Cristina AB Abstract In the Montes de Toledo area, located in theaxial part of the Central Hercynian zone, a long-termthermo-tectonic evolution can be deduced from apatitefission-track (AFT) data in conjunction with tight geologicalconstraints derived from the knowledge of regionalgeology and other independent chronometers.The area is composed of two different blocks separatedby the Toledo Shear Zone (TSZ). The northern block isa granulite facies anatectic terrane. The southern blockis composed of greenschist facies Paleozoic sedimentsintruded by a late Hercynian granitic pluton. A total of13 samples have been recovered for AFT analysis. AFTages in both blocks cluster around 189–221 Ma, withmean confined track lengths between 11.4 lm and12.4 lm. Modeling of the AFT data indicates that thethermal history is broadly similar in both blocks, whichconstrains the main movement of the TSZ, as essentiallybefore the Upper Permian. AFT ages in the TSZ clusteraround 124–164 Ma, and the track lengths vary between11.4 lm and 12.4 lm. These data reveal that the faultmust have been affected by a later thermal overprint asAFT ages are significantly younger than those of thefootwall and hangingwall blocks. This differential thermalresetting is likely related to the advection of localizedhydrothermal fluids that are responsible for thewidespread Pb–Zn mineralization along the TSZ. Theseresults give an example of resetting AFT data byhydrothermal events. The long-term evolution suggests alack of important Alpine tectonism in the Montes deToledo block, in clear contrast to other nearby Hercynianareas such as the Sierra de Guadarrama, where theimportant effect of Alpine tectonism has almost totallyerased the previous thermal signal in the AFT system. PB Springer Science Business Media SN 1437-3254 YR 2005 FD 2005 LK https://hdl.handle.net/20.500.14352/49582 UL https://hdl.handle.net/20.500.14352/49582 LA eng DS Docta Complutense RD 6 abr 2025