Banca de QUALIFICAÇÃO: Yuri Ribeiro
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : Yuri Ribeiro
DATE: 06/10/2023
TIME: 08:00
LOCAL: Sala de Videoconferência do IGD
TITLE:
KEY WORDS:
Rare earth element (REE) minerals, metariolites, REE mineralization, clay adsorption-type deposit.
PAGES: 81
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:
Deposits of rare earth elements (REE) are sources of essential metals for high technology and to drive a more sustainable economy. In the state of Goiás, located in the central region of Brazil, research has been conducted over the past decades to investigate significant rare earth anomalies in type A granites. However, few studies have focused on metavolcanic rocks, which share the same geological context as the granites in this region. Therefore, these rocks provide a valuable case study to understand the factors involved in their formation and present a promising alternative to produce this strategic commodity. This study investigated the mineralogical and geochemical associations of the metavolcanic rocks, as well as providing initial data on their weathering mantle and possible supergene enrichment of REE. The acidic metavolcanic rocks of the Araí Group were analyzed, with a focus on the REE-bearing minerals. Three main groups of rocks were identified: Metariodacites, Metariolites, and Metapyclastics. Metariodacites exhibited an average REE content of 334.2 ppm, while metariolites and metapyclastics had average REE contents of 553.8 ppm and 407.07 ppm, respectively. Petrographic studies revealed the occurrence of both REE minerals and REE-bearing minerals during both the magmatic and post-magmatic phases. During the magmatic phase, minerals such as apatite, thorite, cerianite, and zircon played a fundamental role in fixing the REE contents in the rocks. In the post-magmatic stage, allanite, monazite, titanite, and fluocarbonates developed from pre-existing minerals, contributing to the fixation of REE in the rocks. Soil analyses of the superficial portion, formed from the metavolcanics, identified minerals such as quartz, illite, kaolinite, hematite, and goethite. The soil samples exhibited REE contents ranging from 519.8 ppm to 540.8 ppm, with a higher enrichment in light REE. This concentration and redistribution of elements from the metavolcanic rocks to the soil suggest a potential for the development of a clay adsorption-type REE deposit in this region.
COMMITTEE MEMBERS:
Interno - 1336460 - FEDERICO ALBERTO CUADROS JIMENEZ
Interno - 1852544 - JEREMIE GARNIER
Presidente - 6404885 - NILSON FRANCISQUINI BOTELHO
Interna - 1644358 - PAOLA FERREIRA BARBOSA
Interno - 1057547 - VALMIR DA SILVA SOUZA