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

• Type: Chapter or Part of a Book
• Date: 2010

Authors

A. Mateus (Author) Other; Fernando Noronha (Author) FCUP

Book

Title: Ciências Geológicas-Ensino e Investigação e sua história. Volume II, Geologia Aplicada

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Abstract (EN): Deep geological processes, such as the removal of the thermal boundary layer or detachment of the lithospheric 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-event related to that thermal regime, peaking at ca. 340-325 Ma but remaining high enough for several Ma; as a result 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 a large time-span, allowed the progress of continuous/discontinuous deformation mechanisms, thus promoting the development of different tectonic structures, namely shear zones further subjected to successive reactivation events. Concurrently, it supported an extensive hydrothermal activity throughout the entire crust, involving distinct fluid sources in successively lower P-T conditions along a continuum that provided long-lived systems, some of them comprising significant amounts of ore mineral phases.

Language: Portuguese

Type (Professor's evaluation): Scientific

Notes: KEYWORDS: Epigenetic ore-forming systems; Central-Iberian Zone; Variscan tectono-thermal regime; Persistent and large-scale hydrothermal activity