Academic Journal
Reconstructing the Cryogenian-Ediacaran evolution of the Porongos fold and thrust belt, Southern Brasiliano Orogen, based on Zircon U-Pb-Hf-O isotopes
| العنوان: | Reconstructing the Cryogenian-Ediacaran evolution of the Porongos fold and thrust belt, Southern Brasiliano Orogen, based on Zircon U-Pb-Hf-O isotopes |
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| المؤلفون: | Pertille, Juliana, Hartmann, Leo A., Santos, João Orestes Schneider, McNaughton, Neal, Armstrong, Richard |
| المصدر: | International Geology Review |
| بيانات النشر: | Taylor & Francis |
| المجموعة: | Australian National University: ANU Digital Collections |
| مصطلحات موضوعية: | Zircon U–Pb–Hf–O isotopes, Porongos fold and thrust belt, Camaquã Basin, Pelotas Batholith, Brasiliano Orogen, Dom Feliciano Belt |
| الوصف: | The Neoproterozoic geotectonic triad of the Brasiliano Orogen is reconstructed in southern Brazil from studies focused on the Porongos fold and thrust belt. We integrate field geology with isotopic studies of zircon U–Pb SHRIMP and Lu–Hf–O laser determinations in seven metasedimentary and three metavolcanic rock samples. The results indicate that the Porongos palaeo-basin was derived from mixed sources (3200–550 Ma), with major contributions from Rhyacian (2170 Ma) and Ediacaran (608 Ma) sources. Minor contributions from Archaean to Tonian sources are also registered. The maximum depositional age of the Porongos palaeo-basin is established by the age range of 650–550 Ma with TDM model ages between 2.5 and 1.3 Ga. The reworked signature (εHf values = −34 to −4) and the characteristic crustal magma reservoirs (δ18O ≥5.3 ‰) indicate that these sediments are equivalent to Neoproterozoic granites of the Dom Feliciano Belt. The episodic depositional history started in the Cryogenian (650 Ma) and lasted until the Ediacaran (most likely 570 Ma). A magmatic event of Tonian age is recorded in rhyodacite samples interleaved with the metasedimentary rocks and dated at 773, 801, and 809 Ma. The crustal evolution of the Sul-Riograndense Shield included mountain building, folding and thrusting and flexural subsidence in the foreland. An orogenic triad is revealed as the Pelotas Batholith, the Porongos fold and thrust belt and the Camaquã Basin, all part of the Dom Feliciano Belt. ; The investigation was supported financially through a scholarship to Juliana and a grant to Léo A. Hartmann by Conselho Nacional de Desenvolvimento Científico e Tecnológico of Brazil, Edital Universal-2012. Support from a Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul grant ‘Edital Pesquisador Gaúcho’ is also acknowledged. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/pdf |
| اللغة: | English |
| تدمد: | 0020-6814 |
| Relation: | http://hdl.handle.net/1885/247725; https://openresearch-repository.anu.edu.au/bitstream/1885/247725/3/01_Pertille_Reconstructing_the_2017.pdf.jpg |
| DOI: | 10.1080/00206814.2017.1285257 |
| الاتاحة: | http://hdl.handle.net/1885/247725 https://doi.org/10.1080/00206814.2017.1285257 https://openresearch-repository.anu.edu.au/bitstream/1885/247725/3/01_Pertille_Reconstructing_the_2017.pdf.jpg |
| Rights: | © 2017 Informa UK Limited, trading as Taylor & Francis Group |
| رقم الانضمام: | edsbas.CAAB4F63 |
| قاعدة البيانات: | BASE |
| تدمد: | 00206814 |
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| DOI: | 10.1080/00206814.2017.1285257 |