Banca de DEFESA: LARISSE BARBOSA DA CRUZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LARISSE BARBOSA DA CRUZ
DATE: 29/12/2022
TIME: 09:00
LOCAL: videoconferência - canal Youtube do PPGG
TITLE:

Peraluminous Ediacaran plutonism in the Seridó Belt, NE Brazil: petrographic and geochemical characterization

KEY WORDS:

Borborema Province; NE Brazil; lithogeochemistry; mineral chemistry; peraluminous magmatism; Ediacaran.

PAGES: 88
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

In the Borborema Province (northeastern Brazil) there is a wide distribution of granitic bodies related to Ediacaran to Cambrian magmatism as part of the final phase of the Brasiliano / Panafrican orogenesis. An expressive representative of the Ediacaran peraluminous magmatism south of Jardim do Seridó/RN is the object of this study. The main body, located south of Jardim do Seridó / RN, in the central part of the Seridó Belt, has an outcrop extension of approximately 10 km in the NE-SW direction. For the characterization of the mentioned magmatism, field, petrography, mineral chemistry and whole rock relationships were observed. Petrographically, they are intrusive leucogranites in rocks of the Seridó Group (especially micaschists). The mineralogy of these granites is known for quartz, garnet, biotite, muscovite, albite and celebrated for sillimanite and andalusite. Chemically, they are metaluminous to peraluminous rocks with A/CNK ratio = 0.95-5.84 and normative corundum between 1.30 and 14.03. The modeling of Fractional Crystallization as a differentiation process was carried out from the analysis of trace elements and rare earth elements. The model suggests the formation of a magma with peraluminous composition through 84.3% of fractional crystallization. The tectonic context involves a system of relaxation followed by crustal relaxation associated with the D3 deformational event.

COMMITTEE MEMBERS:
Externo à Instituição - ELTON LUIZ DANTAS - UnB
Externo ao Programa - 3149236 - RAFAEL GONCALVES DA MOTTA - nullPresidente - 350630 - ZORANO SERGIO DE SOUZA