Produção Nacional
The Tectonic Evolution of the São Gabriel Terrane, Dom Feliciano Belt, Southern Brazil: The Closure of the Charrua Ocean
2018; Springer International Publishing; Linguagem: Inglês
10.1007/978-3-319-68920-3_10
ISSN2364-6438
AutoresRuy Paulo Philipp, Márcio Martins Pimentel, Miguel Ângelo Stipp Basei,
Tópico(s)earthquake and tectonic studies
ResumoThe Dom Feliciano Belt (DFB) is an important Neoproterozoic to Cambrian orogenic complex, extending from eastern Uruguay to southern Brazil. It comprises a collage of oceanic domains and continental fragments developed between 0.9 and 0.54 Ga between the Rio de La Plata Craton (RLPC), Nico Perez Terrane (NPT) and Kalahari Craton. In southern Brazil, the DFB comprises two metamorphic-granitic terranes, a batholith and a foreland basin that cover all units. The São Gabriel Terrane (SGT) consists of two Neoproterozoic (Tonian and Cryogenian) juvenile arcs and a late-collisional basin, interleaving with relicts of ophiolitic complexes. A review of the geologic and geochronological data of the SGT is presented. Sm–Nd TDM model ages between 1.2 and 0.8 Ga and positive ɛNd(t) values between +1 and +5 characterize the SGT units. Plate tectonic evolution started with the opening of the Charrua Ocean to the east of the RLPC and west of NPT, between 0.93 and 0.90 Ga. An intraoceanic island arc (Passinho Arc), between 0.89 and 0.86 Ga, and a continental margin arc (São Gabriel Arc), between 0.77 and 0.72 Ga, was generated by eastward and westward subduction and was subsequently accreted to the western margin of the NPT, between 0.71 and 0.70 Ga. The post-collisional stage is marked by the emplacement of late orogenic granites (0.70–0.68 Ga). The late orogenic Pontas do Salso basin presents zircon provenance between 0.86 and 0.68 Ga and represents the collapse of the SGT.
Referência(s)