Tectonic inheritance, structure reactivation and lithospheric strength: the relevance of geological history

Abstract

AbstractTectonic inheritance and structure reactivation have been of interest to geologists since it was noticed in the mid-nineteenth century that younger structures in an area tend to follow the direction of older structures. Three kinds of relationship may exist between these older and younger structures: younger structures may follow the older ones and repeat their function; younger structures may follow older ones, but function in the opposite sense to the older ones; and younger structures bear no relation to the older ones. These are named, respectively, resurrected, replacement and revolutionary structures. We present three examples, on three different scales, of tectonic inheritance and structure reactivation: Mesozoic and Cenozoic Europe on a continental scale; the US Rockies on a regional scale; and the Albula Pass in the Swiss Alps on an outcrop scale. We conclude that structure reactivation on a crustal scale occurs when the protective armour of the mantle lithosphere is removed and that, in such cases, resurrected and replacement structures form. In cratons with thick lithospheric roots, structure reactivation hardly ever occurs and when, in rare cases, it does occur, it commonly generates revolutionary structures. There can be no unique model for lithospheric strength.