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Geological mapping, structural data, and analytical modeling by Díez Fernández et al. (2021), https://doi.org/10.1029/2021tc006791 supported that the Central Unit belonged to a rootless Devonian suture zone contiguous to the SW of its exposure and under the upper section of the footwall to the Azuaga Fault. Late exhumation of the Central Unit was via extrusion from the upper‐middle crust under inclined triclinic sinistral transpression, which favored upright folding of the suture zone. Azor and coworkers argue that the upright folds that affect the Central Unit are local, despite geological maps and structural data demonstrate they are km‐scale and occur all across the Central Unit. Besides ignoring structural data regarding the kinematics of the Azuaga Fault, Azor et al. (2022), https://doi.org/10.1029/2021TC006982 fail to recognize the net upthrown movement of the NE side of the Azuaga Fault, as the Central Unit in that side is juxtaposed against syn‐orogenic strata that rest unconformably onto other metamorphic units in the SW side of the fault. Seismic data that image the Central Unit as a NE‐dipping rock package is used as an argument against the proposal by Díez Fernández et al. (2021), https://doi.org/10.1029/2021tc006791. However, the section of the Central Unit those data account for, are from a different part of the Central Unit, the real dip of some structures in the seismic image is not properly interpreted, and the model by Díez Fernández et al. (2021), https://doi.org/10.1029/2021tc006791 is compatible with a Central Unit that also dips to the NE. Overall, the model proposed by Díez Fernández et al. (2021), https://doi.org/10.1029/2021tc006791 remains valid. Key Points: The Central Unit belonged to a rootless Devonian suture zone contiguous to the SW of its exposureThe late exhumation of the Central Unit was via extrusion from the upper‐middle crust under inclined triclinic sinistral transpressionLate exhumation favored upright folding of the suture zone, exposing it in a tectonic window at the core of the Ossa‐Morena Complex [ABSTRACT FROM AUTHOR]

The Eastern Galicia Magnetic Anomaly is the best studied anomaly of the Central Iberian Arc. This is due to its location, on the Lugo‐Sanabria gneiss dome, and to the fact that its source rocks crop out in the Xistral Tectonic Window. Multiple studies of this anomaly have been carried out, but still, new results keep on shedding light on its understanding. This paper presents the first results on rock magnetic analyses, natural remanent magnetization, anisotropy of the magnetic susceptibility, X‐ray diffraction, and stable isotopes geochemistry carried out on the source rocks of this anomaly. Results suggest that magnetization responds to the increase in oxygen fugacity underwent by rocks affected by late Variscan (330‐300 Ma) extensional tectonics. Extensional detachments were the pathways that allowed the entrance of fluids that led to syntectonic crystallization of magnetite and hematite in metasediments and inhomogeneous S‐Type granitoids derived from their partial melting. Accordingly, magnetization is not linked to lithologies, but to extensional structures developed in the late Carboniferous/earliest Permian, during the Kiaman reverse superchron. Systematic reverse magnetic remanence exhibited by hematite‐bearing samples confirms the age of the magnetization and adds complexity to the interpretation of the anomaly. Understanding the EGMA contributes to the interpretation of other anomalies existing in the CIA, also located on thermal domes. The observed extension‐related magnetization probably affected most of the NW Iberian Massif, thus hindering the study of previous tectonics by paleomagnetic techniques. This work aims to provide new hints to interpret magnetic anomalies located in extensional tectonic contexts worldwide. Plain Language Summary: This paper presents a further step in the understanding of the Eastern Galicia Magnetic Anomaly (Iberian Massif), the biggest and most studied magnetic anomaly in Spain. Understanding the source and age of magnetization of this anomaly is key to understand the age of the Central Iberian Arc as it allows (1) to infer the origin of other anomalies found in the internal zone of the Central Iberian Arc and (2) shed more light on the age of the arc itself. Previous papers on this matter are: Ayarza et al. (2007) and Martínez Catalán et al. (2018), https://doi.org/10.1029/2017tc004887. Both represent the evolution on the investigations carried out in this area after the papers by Aller et al. (1994), https://doi.org/10.1016/0040‐1951(94)90255‐0 and that of de Poulpiquet (2012). The MS submitted now includes new AMS, rock magnetism, NRM, field work, and geochemistry studies of the area and proves the role that late Variscan orogenic extension has played in magnetization. Key Points: NRM of the EGMA exhibits a component of inverse polarity coherent with the characteristics of the Kiaman superchronSynkinematic S‐Type granitoids of the Lugo‐Sanabria dome are heterogeneously but highly magneticLate Variscan extension produced the magnetization of EGMA and other areas at the core of the Central Iberian Arc during the Kiaman superchron [ABSTRACT FROM AUTHOR]

The Calzadilla Ophiolite is an ensemble of mafic and ultramafic rocks that represents the transition between lower crust and upper mantle of a Cadomian (peri‐Gondwanan) fore arc. Mapping and structural analysis of the ophiolite demonstrates that it was obducted in latest Ediacaran times, because the Ediacaran‐Early Cambrian sedimentary series (Malcocinado Formation) discordantly covers it. The ophiolite and emplacement‐related structures are affected by Variscan deformation (Devonian‐Carboniferous), which includes SW verging overturned folds (D1) and thrusts (D2), upright folds (D3), extensional faults (D4), and later faults (D5). These phases of deformation are explained in the context of Variscan tectonics as the result of the progressive collision between Gondwana and Laurussia. Qualitative unstraining of Variscan deformation reveals the primary geometry of Ediacaran‐Cambrian structures and uncovers the generation of east verging thrusts as responsible for the primary obduction of the Calzadilla Ophiolite. Restoration of planar and linear structures associated with this event indicates an Ediacaran, east directed obduction of the ophiolite, that is, emplacement of the Cadomian fore arc onto inner sections of the northern margin of Gondwana. According to regional data, the obduction separates two extension‐dominated stages in the tectonic evolution of the African margin of northern Gondwana preserved in southern Europe. Preobduction extension brought about the onset and widening of fore‐arc and back‐arc basins in the external part of the continent, while postobduction extension facilitated the formation of extensional migmatitic domes, an oceanward migration of back‐arc spreading centers across peri‐Gondwana, and the eventual opening of a major basin such as the Rheic Ocean. Key Points: The Calzadilla Ophiolite is a fore‐arc ensemble obducted onto a section of a peri‐Gondwanan arc in latest Ediacaran timesOphiolite obduction was directed to the ESE (present‐day coordinates), following a vector directed to mainland GondwanaObduction preceded back‐arc and fore‐arc spreading in peri‐Gondwana and was followed by the onset of extensional domes and rifting [ABSTRACT FROM AUTHOR]

The Eastern Galicia Magnetic Anomaly (EGMA) is a conspicuous feature of the aeromagnetic map of Iberia, which structurally overlaps the Lugo and Sanabria domes, two spatially linked late Variscan extensional structures that delineate a segment of the Ibero‐Armorican Arc. In the northern part of the Lugo Dome, the Xistral Tectonic Window exposes a deep section of the continental crust, which includes several extensional detachments and associated shear zones. The aim is to check whether or not there is a correlation between the extensional process and the EGMA. A map of the magnetic anomaly of the Xistral Tectonic Window acquired on land improves the resolution of the aeromagnetic data and shows that the EGMA is actually composed by several shorter wavelength anomalies reaching amplitudes up to 1,214 nT. Their location in relation to outcropping rocks and structures, together with 2‐D modeling, shows a conspicuous link between the anomalies and the extensional detachments. On a larger scale, the EGMA forms the northern part of a largeanomaly occupying the core of the Central Iberian Arc. This anomaly can be related to extension caused by gravitational collapse of the thickened Variscan crust, implying that like the EGMA, local anomalies might reflect extensional structures, many of which may remain buried. Our study may shed light on the origin of magnetic anomalies in other gneiss domes as it shows that they can be related with the doming process instead of being inherited from older rocks presently outcropping at the core of the domes. Key Points: Magnetic anomalies in the Lugo gneiss dome of the NW Iberian Massif are related with outcropping late Variscan extensional detachmentsThe sources of magnetic anomalies are high‐grade metamorphic rocks, including migmatites and inhomogeneous granitesThe Lugo Dome is one of a series that coincides with a broad, curved magnetic anomaly that delineates an orocline in NW Iberia [ABSTRACT FROM AUTHOR]

A regional study starting from detailed geological mapping has been carried out in the Malpica-Tui Complex of Galicia in NW Spain. The complex is formed by two units representing pieces of the external edge of Gondwana, subducted and exhumed during the Variscan collision. The study shows that synsubduction and early synexhumation structures in continental subduction channels tends to be obscured and even erased once exhumation is complete. Detailed structural analysis, matched with the knowledge of the history, and available data for other Galician basal units have elucidated the major structures developed during the subduction-exhumation process. The results include evidence of the plate convergence causing early Variscan continental subduction of the Gondwana margin. Subduction was followed by exhumation driven by ductile thrusting within the subduction channel, which, in turn, provoked crustal duplication in the subducted slab and modified the initial tectonometamorphic architecture of the subduction wedge. The next step was accretion to the adjacent continental domains, placing the subduction wedge on top of unsubducted parts of the Gondwana margin via ductile thrusting. Thrusting was preceded by progressive propagation of a train of recumbent folds toward the foreland that affected the previous structural stack. Subsequent transference of oceanic (Rheic) and peri-Gondwanan terranes to the Gondwana margin took place by out-of-sequence thrusting followed by crustal extensional collapse and strike-slip tectonics. [ABSTRACT FROM AUTHOR]

The two structural units that constitute the ophiolitic complex of the Morais allochthonous complex display different geochemical features. Amphibolites from the lower unit are nearly homogeneous, chemically similar to normal mid-ocean ridge basalts, with low Th/Nb and highly radiogenic Nd isotope signature (Nd = +8.7), and might derive from igneous protoliths formed in an oceanic ridge setting 447 ± 24 Myr ago (Sm-Nd whole rock isochron). In contrast, the upper unit consists largely of metaperidotites together with gabbroic rocks and minor amphibolites and felsic veins. U-Pb zircon ages of the upper unit range from 405 ± 1 Ma to 396 ± 1 Ma. These rocks are geochemically more variable but share in common high Th/Nb ratios and high initial Nd (from +7.5 to +8.9) interpreted to reflect generation above an intraoceanic subduction zone. This implies that the Morais ophiolitic complex is composite and consists of two distinct, relatively thin tectonic slivers that were detached from contrasting oceanic domains before being finally imbricated. This occurred broadly coeval, at the regional scale, with eclogite-facies metamorphism documented in several separate tectonic units of NW Iberia. On the basis of this space and time association, we interpret the early stage of the Variscan (in the broad sense) evolution (circa ≥ 405-400 Ma) in terms of intraoceanic subduction, followed by an arc-continent collision, circa 395 Ma. This model may account for the long-recognized polycyclic evolution of the north Portuguese catazonal complexes without resorting to the existence of a high-grade Precambrian basement. [ABSTRACT FROM AUTHOR]

The Aracena metamorphic belt is a high-temperature/low-pressure (HT/LP) band located at the southern end of the European Variscan chain. It marks a suture between Armorica and Avalonia. This belt is characterized by (1) the presence of mid-ocean ridge basalt-derived metabasites that were affected by an inverted HT/LP metamorphism related to SW verging thrusting, whose thermal peak diachronously migrated eastward; (2) the occurrence of a HT/LP metamorphism, related to an extensional event, affecting continental rocks belonging to the Ossa Morena zone with peak temperatures that are ∼150°C higher than that recorded in the oceanic metabasites; and (3) the presence of near-trench magmatism with high-Mg andesite composition. These and other characteristics can be interpreted in terms of a ridge-trench-trench triple junction that migrated along the Armorican margin during Variscan oblique convergence. [ABSTRACT FROM AUTHOR]