Banca de DEFESA: DERICK GIORDANO FEITOSA GUERRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DERICK GIORDANO FEITOSA GUERRA
DATE: 11/12/2020
TIME: 08:30
LOCAL: Videoconferencia - https://cutt.ly/6fcqwHK
TITLE:

Petrograph, mineral chemistry and litochemistry of Riacho Salgado’s augen gneiss (Lajes/RN), northest of Borboreme Province

KEY WORDS:

augen gneiss; Petrology; Riacho Salgado NE of Brazil

PAGES: 97
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

The paleoproterozoic magmatism in Borborema Province have been studying for better understanding the most importante Earth’s crust formation period, this period of great rock volume in state. In this connection, this article show petrographic, mineral chemistry and litochemistry data of Riacho Salgado augen gneiss (AGRS) located near of Laje’s urban center, of paleoproterozoic age (rhyacian).In addition, state of art was conducted on the augen-type texture and the lithology in question of Rio Piranhas-Seridó Domain (DPS). Three metamorphic events are described in literature, while the present work only two have been described, called M2 and M3, and consequently the definition of differents minerals generation, such as k-feldspar and plagioclase with three generation. Quartz, biotite, amphibole, titanite and opaque minerals show two gerations. Allanite, zircon and apatite are protolith crystals. Epidote, clorite, muscovite and carbonate occur as alteration. The opaque minerals are classified as magnetite, pyrite and ilmenite. From qualitative analyses of petrography,a high grade metamorphic is inferred, in transition from superior amphibole to granulite facies. In SEM, zircon and titanite where indicated of continental crust granites, whereas biotite, rich in annite’s molecule has indicate calcialkaline granites. In SEM zircon and titanite where indicated of continental crust granites, whereas biotite, rich in annite’s molecule has indicate calcialkaline granites. Opaque minerals are classified as magnetite, pyrite and ilmenite. Amphibole are classified as pargasite and magnesian-hornblend of subalkaline and alkaline magmas. The plagioclase are andesine. In lithochemistry, the AGRS shows igneous rovenience, classified as metaluminous, high-K calcalkaline or subalcaline with positive anomalies of Eu. For geotectonic classification suggest for AGRS a continental arc syn subduction, with high Sr-Ba contents and oxidant character. For lithochemical data collected from literature the geochemical classification and geotectonic environment are similar, fortifying theory of same genesis for augen gneiss observed in DPS, immersed in metaplutonic unity of Caicó Complex.

BANKING MEMBERS:
Presidente - 1513243 - MARCOS ANTONIO LEITE DO NASCIMENTO
Externo ao Programa - 3149236 - RAFAEL GONCALVES DA MOTTA
Externo à Instituição - VLADIMIR CRUZ DE MEDEIROS - SGB