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We clarify some statements on our works included by Bahlburg (2021), which we think are confusing and misleading. Clarification is highly necessary to interpreting the evolution of the Devonian proto-Andean margin of Argentina and Chile, and in this work, we show that this clarification is appropriated and should be considered. [ABSTRACT FROM AUTHOR]

Voluminous rhyolitic volcanism along the palaeo-Pacific margin of Gondwana was marked by three principal episodes of magmatism. The first of these ( V1) is essentially coincident with the main episode of Karoo–Ferrar magmatism at ∼184 Ma. A younger ( V2) episode occurred at ∼168 Ma, and a third episode ( V3) occurred in the interval 157–153 Ma. We evaluate the origin of V1 and V2 rhyolites from the Antarctic Peninsula using major and trace element and isotopic (Sr, Nd, O) data. An isotopically uniform (87Sr/86Sri ∼0·707; εNdi ∼ −3) andesite–dacite magma was generated as a result of anatexis of ‘Grenvillian age’ hydrous mafic lower crust, linked to earlier, arc-related underplating. The lower-crustal partial melts would have mixed with fractionated components of the mafic underplate, followed by subsequent storage and homogenization. Early Jurassic ( V1) rocks of the southern Antarctic Peninsula are interpreted as melts of upper-crustal paragneiss, which have mixed with the isotopically uniform magma in upper-crustal magma chambers. The V2 rhyolites are the result of assimilation–fractional crystallization of the isotopically uniform magma. This occurred in upper-crustal magma chambers involving assimilants with similar isotopic composition to that of the magma. A continental margin setting was crucial in developing hydrous, readily fusible lower crust. Lower-crustal anatexis was in response to mafic underplating associated with the Discovery–Shona–Bouvet group of plumes, thought to be responsible for the Karoo magmatic province. The progression (old to young) of volcanism from NE to SW in Patagonia and south to north in the Antarctic Peninsula is consistent with migration away from the mantle plumes towards the proto-Pacific margin of Gondwana during rifting and break-up. [ABSTRACT FROM PUBLISHER]

Abstract: Lu–Hf isotope data are presented for dated Permian zircon grains from six samples of the latest Palaeozoic to Jurassic low-grade metasedimentary rocks of western Patagonia and the northern Antarctic Peninsula, as well as from potential source rocks in the North Patagonian Massif. The results for the metasedimentary rocks yield ε Hf values mostly between −15 and +4 (130 analyses), with a dominant range (more than 85%) of −6 to +1, indicating provenance from Permian magmatic rocks that incorporated continental crust with a significant residence time. Other zircon grains record more negative ε Hf values indicating derivation from yet more mature crustal sources. Permian subvolcanic granites in the North Patagonian massif appear to be the closest large source area and dated zircon grains from eight samples of these granites yield initial of ε Hf values of −12 to +4 (45 measurements), 84% of which fall between −6 and +1, the range shown by the metasediments. However, the North Patagonian massif also contains some more juvenile Permian–Carboniferous components not seen in the metasediments, so that this may not be the primary or unique source. These granites are considered to represent the southernmost extension of the Choiyoi igneous province, which contains abundant Permian rhyolites that crop out on the eastern side of the Andes in central Argentina, for which unpublished Hf isotope data yield a very similar range to that of the metasediments. The widespread nature of the Choiyoi volcanic rocks and the predominance of Permian zircon could make this a more favoured source for the detrital grains. Hf isotope data reinforce the uniformity of the provenance of the turbidite detrital zircons and confirm the Choiyoi igneous province and the Permian granitic rocks of the North Patagonian Massif as feasible sources. They further confirm the dominantly crustal origin of the Permian magmas. A source region involving mixing of, for example, crustal materials of Panafrican/Brasiliano and Grenvillian ages, together with a minor but significant subduction-related magmatic input, is an isotopically feasible explanation and is broadly consistent with the provenance of pre-Permian crust in this region, but the proportions of such a mixture must have remained relatively constant. This supports the proposal that recently recognised but widespread Permian magmatism in Patagonia represents voluminous crustal melting in response to subducted slab break-off. The results are also consistent with the premise that the Antarctic Peninsula and southern Patagonia were closely located from Permian to Jurassic times, receiving detritus from the same source. [Copyright &y& Elsevier]