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

Differential Phanerozoic evolution of cratonic and non-cratonic lithosphere from a thermochronological perspective: São Francisco Craton and marginal orogens (Brazil)

“…Low-temperature thermochronology has only seldomly been applied to basement rocks in the Brazilian interior, in particular not adjacent to our study area, thus the majority of our AFT data covers unexplored locality. Our new AFT data can be compared to a limited number of published AFT results (Amaral-Santos et al, 2019;Carmo, 2005;Doranti-Tiritan et al, 2014;Fonseca et al, 2020;Gallagher et al, 1994;Hackspacher et al, 2004;Jelinek et al, 2014;Martins-Ferreira et al, 2020;Van Ranst et al, 2020a) A clear distinction with respect to the tectonic province can readily be observed in the AFT data set presented here. In general, all AFT central ages range between 386 ± 31 Ma (sample 9) and 59 ± 4 Ma (Sample C11).…”

“…As discussed, a Paleozoic denudational cooling phase (Fig. 6) affected at least the SFC (Jelinek et al, 2014;Japsen et al, 2012 at the craton's continental margin) and Brasília Orogen (Fonseca et al, 2020). In the Matiqueira Province (Borba et al, 2002(Borba et al, , 2003Hueck et al, 2019;Machado et al, 2019;Oliveira et al, 2016;Ribeiro et al, 2005;Souza et al, 2014), Amazonian Craton (Harman et al, 1998) and ancient West Gondwana basement terrains in Africa (Kasanzu, 2017;Kasanzu et al, 2016), a Paleozoic cooling is also reported.…”

“…Previous AFT data have also revealed a Paleozoic cooling period in the southern Brasília Orogen (Doranti-Tiritan et al, 2014;Fonseca et al, 2020;Gallagher et al, 1994;Ribeiro et al, 2005) and in the north-eastern SFC (Jelinek et al, 2014;Japsen et al, 2012). Fonseca et al, 2020 suggest a close connection between the tectonic subsidence of the Paraná Basin and the coeval cooling of the Brasília Orogen. This is interpreted as a result of exhumation after possible reactivation and basement denudation, which in turn was triggered by the tectonic extension during the rifting processes.…”

“…D) Chronostratigraphic regional map showing the location of analyzed samples with the major structural lineaments and AFT ages from previous works. * indicates samples from Fonseca et al (2020).…”

“…The majority of the previous works argued for a far-field mechanism inducing widespread erosion and exhumation of the West Gondwana basement during this time (e.g. Fonseca et al, 2020). It is likely that other portions of the West Gondwana basement have also experienced this cooling phase but it is not recorded by low-temperature thermochronometers due to either posterior resetting by subsequent thermal events, or because more recent exhumation events have removed the overlying basement with this signal, exposing deeper sections of the crust.…”