New insights into the Gondwana breakup at the Southern South America by apatite fission-track analyses

• Main Authors: C. H. Gomes, D. Almeida
• Format: Article
• Language: English
• Published: Copernicus Publications 2019-01-01
• Series: Advances in Geosciences
• Online Access: https://www.adv-geosci.net/47/1/2019/adgeo-47-1-2019.pdf

<p>Apatite fission-track (AFT) analyses, applied to Southern Brazil and Uruguay samples, was employed aiming to understand the low temperature history of the Dom Feliciano Belt Segment. The Dom Feliciano Belt formed during the Neoproterozoic to Early Paleozoic, linked to the Brasiliano/Pan-African Orogeny. Twenty-four samples were dated, and confined track lengths of twenty samples were measured. The spatial distribution of ages shows three domains with different evolution cut by shear zones and, or suture zones in the Dom Feliciano Belt. The Western Domain exhibits AFT ages &gt;&thinsp;250&thinsp;Ma (Permian to Devonian) while the Eastern Domain shows AFT ages &lt;&thinsp;230&thinsp;Ma (Paleogene to Triassic). In the Central Domain, the AFT ages range from <span class="inline-formula">∼196</span> to 130&thinsp;Ma (Jurassic to Early Cretaceous). The thermal modeling in the domains revealed a complex evolution, with cooling and reheating phases, and a denudation of <span class="inline-formula">∼2600</span>&thinsp;m. The AFT ages clearly postdate the Gondwanide, Paraná-Etendeka and Rio Grande Cone exhumation history of the Dom Feliciano Belt.</p>