Detrital zircon U-Pb ages and whole-rock geochemistry of the Neoproterozoic Paulistana and Santa Filomena complexes, Borborema Province, northeastern Brazil: implications for source area composition, provenance, and tectonic setting

Autor(es)

Santos, Felipe H. ^[1] ; Amaral, Wagner S. ^[1] ; Uchoa Filho, Evilarde C. ^[2] ; Martins, Douglas T. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Geosci, Dept Geol & Nat Resources, POB 6152, BR-13083970 Campinas, SP - Brazil

^[2] CPRM Geol Survey Brazil, Teresina - Brazil

^[3] Inst Educ Ciencia & Tecnol Piaui IFPI, Paulistana - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL GEOLOGY REVIEW; v. 59, n. 15, p. 1861-1884, 2017.
• Citações Web of Science: 2

Resumo

The Paulistana and Santa Filomena Complexes are situated in the southern part of the Borborema Province (northeastern Brazil), in the Riacho do Pontal Orogen, and represent meta-volcano-sedimentary sequences. We present compositional variations in the metasedimentary rocks and new U-Pb detrital zircon data. Major and trace elements indicate that the metasedimentary rocks from the Paulistana and Santa Filomena Complexes are composed mostly of immature to mature sediments derived from felsic-intermediate sources with moderate to slightly high chemical weathering. The geochemical signatures of the sediment protoliths for both complexes are characteristic of continental magmatic arc settings with minor contribution from recycled sediment sources. The source area for the Paulistana Complex rocks follow the compositional trend between calc-alkaline granites and granodiorites, whereas the Santa Filomena Complex rocks have a more restricted composition trending to more granodioritic sources. For the Paulistana Complex, two main source ages were identified: (1) Tonian (ca. 950Ma - sample RPE-58) and Tonian-Stenian (ca. 1.0Ga - sample RPE-103). These data coupled with geochemical information suggest that the Cariris Velhos arc system was the main source area for the Paulistana Complex. Regarding the Santa Filomena metasedimentary rocks, potential source-areas include: (1) Neoarchaean rocks (similar to 2.6Ga) represented by the adjacent basement rocks of the Riacho do Pontal Orogen; (2) Rhyacian-Orosirian rocks (2.2-2.0Ga) of the Riacho do Pontal Orogen and the Pernambuco-Alagoas terrain, which include an augen-gneiss with arc-related geochemical signature; (3) Statherian granites (1.7-1.6Ga); and (4) Cariris Velhos crust (1000-920Ma). The metasedimentary rocks of the Paulistana Complex were deposited in a rift stage (ca. 900Ma), which is related to the break-up of the Rodinia supercontinent. The metasedimentary rocks of the Santa Filomena Complex most probably were deposited in another rift stage (ca. 750-700Ma) and could be correlatives of the rift formation of the Caninde Domain (Sergipano Orogen). (AU)

• Processo FAPESP: 14/03275-3 - Geocronologia, geoquímica e metamorfismo do domínio interno da faixa de dobramentos Riacho do Pontal
• Beneficiário: Wagner da Silva Amaral
• Modalidade de apoio: Auxílio à Pesquisa - Regular