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The NW Iberian Allochthon and the Tepla-Barrandian and Moldanubian zones represent the internal parts of the Variscan belt in their respective domains. A correlation based on the lithological association, protolith ages, metamorphic evolution, detrital zircon age spectra and tectonic setting is attempted between the NW Iberian Massif and SE Bohemian Massif in order to check whether they could have formed part of the same allochthonous stack. The Galicia-Tras-os-Montes Zone of the Iberian Massif and the internal zones of the Bohemian Massif include from bottom to top a Parautochthon and Lower Allochthon representing the outer edge of the northern Gondwana margin, an oceanic Middle Allochthon with Cambro-Ordovician and Early Devonian ophiolites and an Upper Allochthon interpreted as a peri-Gondwanan terrane. Early Variscan, subduction-related high-pressure metamorphism characterizes many of the allochthonous units, with ages younging from the structurally upper to the lower units from 400–385 Ma to 370–360 Ma, respectively. High- and ultrahigh-pressure metamorphism occurred also in the Saxothuringian Autochthon at 360–340 Ma, but not in the NW Iberian Autochthon. The different behavior of the Autochthon in the Iberian and Bohemian massifs accounts for their distinct evolutions from 360 Ma onward. We conclude that the Upper Allochthon was a unique peri-Gondwanan terrane, whereas the Middle Allochthon represents units of the same peri-Gondwanan ocean, opened at the Cambro-Ordovician boundary, and having recorded localized renewed activity in the Silurian–Early Devonian. No other oceans separated the Lower Allochthon, Parautochthon and Autochthon.

The Intra-Sudetic Basin, a ~ 12 km deep Variscan intramontane basin, has the best preserved post-orogenic sedimentary record available at the NE margin of the Bohemian Massif. Apatite fission track (AFT) analyses have been performed on 16 sedimentary and volcanic samples of Carboniferous to Cretaceous age from the Intra-Sudetic Basin to improve understanding of the post-Variscan thermal evolution. AFT central ages range from 50.1 ± 8.8 to 89.1 ± 7.1 Ma (Early Eocene to Coniacian), with 13 of them being Late Cretaceous. The mean track length values range from 12.5 ± 0.4 to 13.8 ± 0.5 (except for one sample 14.4 ± 0.2) µm. This relatively short mean track length together with the unimodal track length distributions and rather low standard deviation (0.8 to 1.7 µm) in most samples indicate a long stay in the partial annealing zone during slow cooling. However, in the northern part of the Intra-Sudetic Basin, samples show a wider track length distribution (standard deviation of 1.8 to 2.1 µm) that could indicate a more complex thermal evolution possibly related to Mesozoic reheating. Vitrinite reflectance data combined with thermal models based on the AFT results indicate that the Carboniferous strata reached maximum palaeotemperatures in the latest Carboniferous to Early Permian time, corresponding to a major coalification event. The second phase of temperature rise occurred due to Late Mesozoic sedimentary burial, but it had no influence on maturation of the Carboniferous organic matter. Final cooling phase in the Late Cretaceous–Paleogene was related to tectonic inversion of the Intra-Sudetic Basin, which occurred after deposition of a significant thickness of Cenomanian–Turonian sediments. Thermal modelling demonstrates that ~ 4 km thick cover of Upper Cretaceous sediments is required to obtain a good match between our AFT data and modelled time–temperature paths. This outcome supports a significant amount of Late Cretaceous–Paleogene inversion within the Variscan belt of Central Europe.

The authors of the Comment suggest that our geological overview map of the European Variscides is incorrect in the section showing SW Iberia (our Fig. 1a). However, our paper reports results of the provenance study from the northern Rhenish Massif, and does not attempt to discuss the architecture and tectonic evolution of the Appalachian-Variscan belt. The aim of Fig. 1 is to locate the study area in the geological context of the European Variscides and not to extrapolate the implications of our findings down to southern Portugal. The map is mostly based on Franke (2014) that is explicitly stated in the caption. Our results are neutral towards the hypothetical correlation between the Mid-German Crystalline High and the southern domains of the Ossa-Morena Zone that is shown on the map[…]

Results of a depth-to-basement study are presented for the East European Craton and the Teisseyre-Tornquist Zone (TTZ) in Poland. The terrestrial gravity data are inverted for the top of the Paleoproterozoic basement and, independently, for the top of the Ediacaran using seismic horizons from the PolandSPAN™ seismic survey and well tops as input depth measurements. The depth to the Ediacaran modelling was additionally extended to cover the Łysogory Block and northern Malopolska Block. The results are visualised as isobath maps for the top of the Paleoproterozoic basement and top of the Ediacaran and an isopach map for the Ediacaran, supplemented with qualitative structural interpretation based on gravity and magnetic data. The results of modelling show a smooth crystalline basement slope within the TTZ with the top of the Paleoproterozoic basement uniformly descending south-westwards by 10–14 km. The thickness of the Ediacaran in SE Poland increases in the same direction to more than 10 km within the TTZ. Such a crustal architecture, in combination with the earlier documented Moho elevation of 4–6 km, reveals significant thinning of the Paleoproterozoic crust within the TTZ to form a crustal necking zone due to the Ediacaran rifting. A smooth geometry of the top of basement along with the lack of basement-rooted faults suggests a ductile mode of crustal thinning during rifting of Rodinia. Moreover, the development of the NW–SE-oriented rift, a precursor of the Tornquist Ocean, was associated with rifting in a NE–SW direction parallel to the Orsha-Volyn Rift.

The Carboniferous foreland basin of western Poland contains a coherent succession of late Visean through Westphalian turbidites derived from a uniform group of sources located within a continental magmatic arc. Detrital zircon geochronology indicates that two main crustal components were present in the source area of Namurian A sediments. They represent Late Devonian and Early Carboniferous ages, respectively. The detritus from Westphalian D beds is much more diversified and contains admixture of Late Carboniferous zircons suggesting rapid unroofing of Variscan igneous intrusions in the hinterland between Namurian A and Westphalian D times. Tectonic repetitions of tens of metres thick fault-bounded stratigraphic intervals, recorded in several wells, provide evidence for compressional regime that occurred in the SW part of the Carboniferous basin not earlier than during the Westphalian C and produced NW-SE trending folds, concordant with the structural grain of the adjacent, NE part of the Bohemian Massif.

SHRIMP dating of detrital zircons from sandstones of the Gackowa Formation (Kaczawa Complex, Sudetes, SW Poland) indicates input from late (550–750 Ma) and early Proterozoic to Archaean sources (∼2.0–3.4 Ga, the latter being the oldest recorded age from the Sudetic region). These dates preclude within-terrane derivation from seemingly correlatory acid volcanic rocks of early Palaeozoic age. Rather, they indicate provenance from Cadomian and older rocks that currently form part of other, geographically distant terranes; the most likely source identified to date is the Lusatian Block in the Saxothuringian Zone. Hence, the Gackowa Formation may be late Proterozoic rather than early Palaeozoic in depositional age, possibly coeval with the late Proterozoic (pre-Cadomian) greywackes of Lusatia, being subsequently tectonically interleaved with early Palaeozoic volcanic rocks into the Kaczawa accretionary prism during the Variscan orogeny. However, correlation with the lithologically similar early Ordovician Dubrau Quartzite of Saxothuringia, and so assignation to the early Paleozoic (post-Cadomian) rift succession deposited at the northern margin of Gondwana, cannot yet be precluded.

The southern and eastern Karkonosze–Izera massif (northern Bohemian Massif) exposes blueschist facies rocks and MORB-type magmatic complexes. During Late Devonian to Early Carboniferous times, these were overthrust within a nappe pile toward the NW onto the pre-Variscan Saxothuringian basement composed of the Izera–Kowary metagranitoids and their envelope. The lowermost nappe (or parautochthonous?) unit of the pile is the low-grade metamorphosed Jestěd complex, comprising a Devonian to Early Carboniferous sedimentary succession of the Saxothuringian passive margin. This is tectonically overlain by the South Karkonosze complex, which represents Ordovician–Silurian volcano-sedimentary infill of the Saxothuringian basin, affected by Late Devonian HP metamorphism. The uppermost nappe is the Early Palaeozoic epidote–amphibolite grade Leszczyniec MORB-like complex, cropping out on the eastern margin of the Karkonosze–Izera massif. It probably represents a fragment of obducted Saxothuringian basin floor. The nappe pile was stacked beneath the overriding upper plate margin, now concealed below the Intra–Sudetic basin and hypothesized to represent a fragment of the Tepla–Barrandian terrane. The nappe stacking, triggered by buoyancy-controlled upward extrusion of the subducted continental slab, was the main mechanism for the exhumation of HP rocks. The final stages of the NW-ward nappe stacking were accompanied and followed by SE-directed Early Carboniferous extensional collapse. The lower plate of the suture zone was uplifted at that time and intruded by the ~330-Ma-old, nearly undeformed Karkonosze granite pluton. As a result of the collapse, the Tepla–Barrandian(?) upper plate was downthrown on shear zones and brittle faults and buried under several km-thick synorogenic Late Tournaisian(?) through Namurian and post-orogenic Late Carboniferous–Early Permian succession of the Intra–Sudetic basin. The south and east Karkonosze suture most probably is a fragment of the Tepla/Saxothuringian (Munchberg–Tepla) suture belt known from the western Bohemian Massif.