Unveiling the stratigraphy of the northern Punta del Este Terrane (Jaguarao Domain) and its role in the Neoproterozoic tectonic evolution of the Dom Feliciano Belt (southern Brazil and Uruguay)

Author(s)

da Cruz, Rodrigo Fabiano ; Basei, Miguel Angelo Stipp ; Philipp, Ruy Paulo ; Iglesias, Carlos Moacyr da Fontoura

• Document type: Journal article
• Source: INTERNATIONAL GEOLOGY REVIEW; v. N/A, p. 23-pg., 2023-07-08.

Abstract

The Punta del Este Terrane, located in southeastern Brazil and eastern Uruguay, is a tectonostratigraphic terrane recognized in the Dom Feliciano Belt, the southern segment of Mantiqueira Province (Brasiliano Orogen). The northern sector of the terrane, called here by the Jaguarao Domain, is constituted by Arroio Telho, Arroio Grande, Matarazzo metamorphic complexes, and the Arroio Pedrado Gneisses. The first is composed of low to medium-grade metasedimentary rocks. Metasiliciclastic schists and marbles constitute the second, with serpentinites, magnesian schists, amphibolites, and metagabbros. The Matarazzo Complex comprises pure and siliceous dolomitic marble, metadolerite, and metagabbro. Arroio Pedrado unit comprises granodioritic to monzogranitic augen-gneisses. The rocks of the complexes were poly-deformed and intruded by high-K calc-alkaline peraluminous and metaluminous granitoids. The Pedro Osorio, Arroio Grande, and Cerro Amaro dextral shear zones delimited the domain to the north. To the south and east, the units of the Jaguarao Domain were covered by coastal plain sediments. In gravimetric maps, the domain shows a high-density relief in contrast with the rocks of the granite belt (Pelotas Batholith). U-Pb zircon data from garnet-muscovite granites present crystallization ages of 587-568 Ma, which point to a widespread Ediacaran magmatism in the northern Punta del Este Terrane. U-Pb zircon provenance data of the metasedimentary sequences indicate main Meso- to Paleoproterozoic contribution, with subordinate Tonian to Cryogenian age populations. The geochronological results of the supracrustal rocks indicate a sedimentary deposition in an extensional setting, in which posterior deformation and metamorphism/magmatism compatible with a syn-orogenic setting in the context of the Dom Feliciano Belt framework. (AU)

• FAPESP's process: 15/03737-0 - The Rio de La Plata Craton and the Western Gondwana Assembly
• Grantee: Miguel Angelo Stipp Basei
• Support Opportunities: Research Projects - Thematic Grants