SISTEMAS MINERALIZANTES EPIGENÉTICOS NA ZONA CENTRO-IBÉRICA;EXPRESSÃO DA ESTRUTURAÇÃO OROGÉNICA MESO- A TARDI-VARISCA

Abstract

Deep geological processes, such as the removal of the thermal boundary layer or detachment of thelithospheric mantle, were crucial to sustain a large-scale high thermal regime during the Variscan orogeny.The genesis and emplacement of voluminous granitoid rocks represent the main effect of an HT-eventrelated to that thermal regime, peaking at ca. 340-325 Ma but remaining high enough for several Ma; as aresult of a rapid crustal uplift occurred at ca. 300 Ma, surface heat flow anomalies were developed,enduring at least till ca. 280 Ma. This evolving thermo-tectonic setting, reducing the crustal strength for alarge time-span, allowed the progress of continuous/discontinuous deformation mechanisms, thuspromoting the development of different tectonic structures, namely shear zones further subjected tosuccessive reactivation events. Concurrently, it supported an extensive hydrothermal activity throughoutthe entire crust, involving distinct fluid sources in successively lower P-T conditions along a continuum thatprovided long-lived systems, some of them comprising significant amounts of ore mineral phases.