Geología de las Zonas Centro Ibérica y Galicia – Trás-os-Montes en la parte oriental del Complejo de Morais, Portugal/España
Ícaro Fróis Dias da Silva, 2013
Tesis doctoral
Universidad de Salamanca
9
Domain (Parautochthonous Nappe Complex) is composed by low-grade Cambro-Silurian
preorogenic sequences with Gondwanan affinity and by Late Devonian-early Carboniferous
synorogenic deposits (Pereira
et al.
, 1999; Valverde-Vaquero
et al.
, 2005; González Clavijo, 2006;
Ribeiro
et al.
, 2006; Rodrigues
et al.
, 2006a; Valverde-Vaquero
et al.
, 2007b; Martínez Catalán
et al.
,
2009; Meireles, 2012).
Table 1.1-
Proposals for the division of the allochthonous domains of the Galicia – Trás-os-Montes Zone
according to Ribeiro (1974), Rodrigues
et al.
(2006a, b), Pereira,
et al.
(2006), and Arenas
et al.
(2004). Blue:
Upper Allochthonous Complexes; Yellow: Lower Allochthonous Domain.
The Schistose Domain of Galicia Trás-os-Montes (SDGTM; Farias
et al.
, 1987) is divided in
Portugal into Upper and Lower Parautochthonous domains (or Sub-Autochthonous; Pereira
et
al.
, 2006a; Rodrigues
et al.
, 2006b), separated by a first order C2 structure. The Upper is
composed by recumbently folded preorogenic deposits, while the Lower includes part of a
Silurian-Early Devonian sequence identical to that of the autochthon, and synorogenic sediments
imbricated in thrust slices.
The sedimentation of the synorogenic formations was not exclusive of the GTMZ – CIZ
boundary, but it took place on the autochthonous and parautochthonous terranes. The oldest
basins (Late Devonian to early Carboniferous) are located in the most internal orogenic areas
while the youngest basins occur in the most external (Martínez Catalán
et al.
, 2008), reaching ages
as young as Stephanian in the Cantabrian Zone (Pastor-Galán
et al.
, 2012).
Both CIZ and SDGTM were affected by LT Barrovian metamorphism (M1) during the
initial phases of the Variscan orogeny (C1 and C2), as a result of the amalgamation of Pangea
super continent. M1 was overprinted by HT-LP regional metamorphism during the development
of gneiss domes, both related with the synorogenic extensional collapse (E1) which led to the M2
regional event (Escuder Viruete
et al.
, 1994a; Escuder Viruete
et al.
, 2004; Valverde-Vaquero
et al.
,
2007a; Alcock
et al.
, 2009; Alcock
et al.
, 2012).
Ribeiro (1974), Rodrigues et al, (2006a,b) and Pereira et al, (2006)
Arenas et al. (2004)
ALLOCHTHON
(*PNC - Parautochthonous Nappe Complex)
GALICIA - TRÁS-OS-MONTES ZONE
Upper Units
Medium pressure
Upper Allochthonous Complex
High pressure and High temperature
Ophiolithic Complex
Ophiolithic Units
Lower Allochthonous Complex
Basal Units
Parautochthon
Schistose Domain
STRUCTURAL UNITS
A U T
O C H T
H O N
Main Trás-os-Montes Thrust
Lower Allochthonous Thrust
Upper Parautochthonous Domain
Sub-autochthonous or Lower Parautochthonous Domain
Palheiros - Vila Flor Thrust
P
N
C
*
Introduction
