Banca de DEFESA: DAYVISON BRUNO CORDEIRO DE PAIVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DAYVISON BRUNO CORDEIRO DE PAIVA
DATE: 30/01/2020
TIME: 09:00
LOCAL: Auditório do departamento de geofísica
TITLE:

GEOCHEMISTRY, MAGMATIC EVOLUTION AND CRYSTALLIZATION CONDITIONS OF
THE SÃO JOÃO DO SABUGI PLUTON, RN

KEY WORDS:

São João do Sabugi Pluton; Lithochemistry; Geochemical Modeling; Crystallization Conditions.

PAGES: 110
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

The São João do Sabugi Pluton, near the homonymous city in the Rio Grande do Norte state, is one of the most expressive occurrences of shoshonitic rocks within the Rio Piranhas – Seridó Domain of the Borborema Province. The petrography and chemistry (whole-rock and mineral chemistry) of the pluton was investigated in order to better characterize the involved magmatic differentiation processes and the crystallization conditions. The identified lithotypes were grouped into three petrographic facies: dioritic facies, with gabbro-dioritic rocks containing the mafic paragenesis clinopyroxene ± orthopyroxene ± amphibole ± biotite; monzodioritic facies, including diorite and monzodiorites, as well as quartz monzonites with amphibole ± biotite; and granodioritic facies, with the more felsic and evolved lithotypes containing biotite as the main mafic mineral, and higher contents of alkaline feldspar over plagioclase. The studied rocks are metaluminous and show high-K calc-alkaline to shoshonitic signatures. Textural evidences and geochemical modeling suggest that the pluton magmatic evolution was mainly governed by fractional crystallization processes coupled with assimilation of paragneisses and calc-silicate rocks of the Jucurutu Formation (AFC processes). The magmas that have built the São João do Sabugi Pluton crystallized at temperatures of 730 – 740 o C, under pressures of 5 – 6 kbar.

BANKING MEMBERS:
Externa à Instituição - ANELISE LOSANGELA BERTOTTI - UFPE
Presidente - 2042352 - FREDERICO CASTRO JOBIM VILALVA
Interno - 1513243 - MARCOS ANTONIO LEITE DO NASCIMENTO