Natural processes driven by heat flow can be understood using quantitative reconstruction of the thermal history of accessory and common minerals that were formed or modified in these processes. Thermochronology assumes that isotopes are lost from minerals by thermally-activated volume diffusion, and forms the basis of many studies of the thermal evolution of the crust. However, some studies challenge this assumption and suggest that the mechanisms controlling isotope transport in minerals over geological time-scales are dominated by aqueous fluid flow within mineral pathways. Here, we test these contrasting hypotheses by inverse modelling apatite uranium–lead (U–Pb) dates to produce theoretical t–T solutions assuming Pb was lost by volume diffusion. These solutions are compared with independent geological constraints and intra-grain apatite U–Pb dates, which demonstrate that volume diffusion governed the displacement of Pb. This confirmation, combined with an inverse-modeling procedure that permits reheating and cooling paths to be distinguished between ∼375 and 570 °C, provides geologists with a unique tool for investigating the high-temperature thermal evolution of accessory minerals using the U–Pb method

The Northern Apennines (NA) orogenic wedge formed during Oligocene‐Miocene convergence and westward subduction of Adria beneath the European Plate. Extension ensued in the Mid‐Late Miocene in response to Adria roll‐back, causing opening of the back‐arc Northern Tyrrhenian Sea. Whether extension continues uninterrupted since the Mid‐Late Miocene or it was punctuated by short‐lived compressional events, remains, however, uncertain. We used the K‐Ar method to date a set of brittle‐ductile and brittle deformation zones from the Island of Elba to contribute to this debate. We dated the low‐angle Zuccale Fault (ZF), the Capo Norsi‐Monte Arco Thrust (CN‐MAT), and the Calanchiole Shear Zone (CSZ). The CN‐MAT and CSZ are moderately west dipping, top‐to‐the‐east thrusts in the immediate footwall of the ZF. The CSZ slipped 6.14 ± 0.64 Ma (<0.1 μm fraction) and the CN‐MAT 4.90 ± 0.27 Ma ago (<0.4 μm fraction). The ZF, although cutting the two other faults, yielded an older age of 7.58 ± 0.11 Ma (<0.1 μm fraction). The ZF gouge, however, contains an illitic detrital contaminant from the Paleozoic age flysch deformed in its hanging wall and the age thus is a maximum faulting age. Removal of ~1% of a 300‐Ma‐old contaminant brings the ZF faulting age to <4.90 Ma. Our results provide the first direct dating of brittle deformation in the Apennines, constraining Late Miocene‐Early Pliocene regional compression. They call for a refinement of current NA geodynamic models in the framework of the Northern Tyrrhenian Sea extension.