Dating deformation by the 40Ar/39Ar method: a review
Chiara Montemagni, Igor M. Villa
Abstract
Shear zones contribute to the building of orogens by localising displacements and element transfer between tectonic units, leading to both underthrusting and exhumation of large domains of the lithosphere. Constraining their activity over time is fundamental for understanding the tectonic processes and consequently producing realistic geological models. The 40Ar/39Ar dating method is an invaluable tool capable of extracting chronological information from a large variety of magmatic, metamorphic and metasomatic mineral chronometers. In particular, its ability to recognise and date sequential recrystallisation event(s) by using compositional fingerprinting and/or in situ analyses provides constraints on the timescales of a wide range of geological processes.