Devonian to Permian post-orogenic denudation of the Brasilia Belt of West Gondwana : insights from apatite fission track thermochronology

The Brasilia Belt in southern Brazil is a Neoproterozoic orogenic belt that represents the northern border of the Parana Basin, a long-lived early Paleozoic intracratonic basin. The belt is surrounded by cratonic domains and were modestly affected and reactivated by the opening of the South Atlantic Ocean during the Cretaceous. Here we present new apatite fission track data from crystalline rocks of the Brasilia Belt. The apatite fission track central ages range from 386 to 243 Ma and the mean track lengths range between 13.4 and 14.5 mu m. Thermal history modeling reveals Devonian to Permian cooling, which we interpret as the main final exhumation of the Brasilia Belt, implying that indeed the influence of posterior Mesozoic and Cenozoic geodynamic history on the belt was limited. The Parana Basin and surrounding elevated terranes therefore provide a time window to study the tectonic history of Gondwana and the effect of far-field intraplate stresses on the interior of West Gondwana. Rapid basement exhumation of the Brasilia Belt is coeval with extension and tectonic subsidence in the Parana Basin as a result of continent-scale tectonic forces occurring over entire West Gondwana

Reply to the comment on 'Devonian to Permian post-orogenic denudation of the Brasília Belt of West Gondwana : insights from apatite fission track thermochronology' by Alessandretti and Warren, 2021

Here we reply to the comment by Alessandretti and Warren, (2021) on the paper "Devonian to Permian postorogenic denudation of the Brasilia Belt of West Gondwana: insights from apatite fission track thermochronology " by Fonseca et al. (2020). We have the impression that many of the remarks, at least to some extent stem from a misunderstanding of our manuscript, also considering that they did not propose any alternative hypothesis for interpretation of our results presented in the aforementioned paper. We, thus, reiterate our interpretations from our low-temperature thermochronology data. The basement of the Brasilia Belt was subject to a significant exhumation during the Devonian to the Permian through erosion, and was likely a source area for detrital sediments deposited in parts of the northeastern Paran & PRIME;a Basin at that time. Apatite fission-track data show that Meso-Cenozoic events had limited effect on post-orogenic exhumation of the Brasilia Belt, in contrast to e.g. the Aracuai Belt