Paleoproterozoic basement of Içana Domain, Rio Negro Province, northwestern Amazonian Craton: Geology, geochemistry and geochronology (U-Pb and Sm-Nd)

Autor: Marcelo Esteves Almeida, Marcia Caroline R. Carneiro, Jean-Louis Paquette, Rielva Solimairy Campelo do Nascimento, Renata da Silva Veras
Přispěvatelé: Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC)
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Journal of South American Earth Sciences
Journal of South American Earth Sciences, Elsevier, 2018, 86, pp.384-409. ⟨10.1016/j.jsames.2018.07.003⟩
Journal of South American Earth Sciences, 2018, 86, pp.384-409. ⟨10.1016/j.jsames.2018.07.003⟩
ISSN: 0895-9811
Popis: The oldest rocks of the Rio Negro Province in the Amazonian Craton, have a complex evolutionary history and little known about them. In this paper are presented field, microtextural data, amphibole and plagioclase mineral chemistry, zircon U–Pb ages, and Sm–Nd isotope composition from Icana Domain basement rocks which belong to the Rio Negro Province. The studied area of the province is located in the extreme northwestern portion of Brazil (Amazonas State). The integration of the data obtained in this study allowed to propose the tectono-metamorphic evolution of Icana Domain in the Rio Negro Province. The basement rocks comprise orthogneiss and metagranite of the Cauaburi Complex and homogeneous/heterogeneous diatexite of the Taiuacu–Cauera diatexite. The Cauaburi Complex rocks exhibit a predominantly porphyroclastic texture and has a mafic mineralogy constituted by biotite, amphibole, sphene, epidote, and allanite. On the other hand, Taiuacu–Cauera diatexite varies from inequigranular to porphyroclastic, being constituted by biotite, muscovite, allanite, and epidote. Basement rocks of the Icana Domain record three tectonic–metamorphic events, which were associated to regional events. The M 1 /D 1 event was marked by the syn-tectonic emplacement of the Cauaburi Complex protolith rocks (1813 ± 19 Ma), and also by crystallization (1821 ± 14 Ma) and migmatization (1788 ± 11 Ma) of the Taiuacu-Cauera diatexites in an orogenic event. The M 2 /D 2 event reached high temperatures, similar to the M 1 /D 1 event and was related to emplacement of S–type granites in the Icana Domain basement during the Icana Orogeny (ca. 1520 Ma). Furthermore, the lower temperature of the M 3 /D 3 event was related to intracontinental reworking of the K'Mudku event (ca. 1200 Ma). The Cauaburi Complex basement rocks shows epsilon Nd (t) values range from +1.53 to +0.13, which allow the identification of a crustal contribution to the magma source (likely Orosirian sialic crust). Geochemistry data indicate that these rocks have been generated from partial melting of amphibolitic rocks, and also with an important crustal component related to magmatic arc settings. All igneous (1967 ± 25 Ma) and metamorphic (1911 ± 15 Ma) zircons grains within the Cauaburi Complex basement rocks are compatible with those found in Tapajos-Parima/Ventuari–Tapajos Province, reinforcing the crustal contribution hypothesis. Geochemistry and mineralogical data indicate that Taiuacu-Cauera diatexite was likely formed by the partial melting of the metagraywacke. Two age populations (1993 ± 33 and 1842 ± 9 Ma) from detrital zircon of the homogeneous diatexite, suggest that the sediments were derived from different rocks of the Tapajos-Parima/Ventuari–Tapajos Province. The age of the Taiuacu-Cauera diatexite is probably between 1842 ± 9 Ma (youngest detrital zircon) and 1788 ± 11 Ma (anatectic zircon). The youngest detrital zircon (1842 ± 9 Ma) and anatectic zircons (1788 ± 11 Ma), indicates that the protolith of Taiuacu-Cauera diatexite is not a part of the Tunui basin (Tunui Group).
Databáze: OpenAIRE
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