Banca de DEFESA: DARLISSON FERNANDES BENTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : DARLISSON FERNANDES BENTO
DATA : 21/02/2020
HORA: 14:30
LOCAL: Sala 107 - Campus Amazônia
TÍTULO:

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PALAVRAS-CHAVES:

Clay minerals. Paleoclimate. Savannah. Amazon

PÁGINAS: 42
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

The formation of clay minerals, in some cases, is directly related to climatic parameters, its
interpretation for paleoclimate purposes is based on certain assumptions and has been used for
paleoenvironmental studies, showing itself as a complementary tool. Variations in the
occurrence of these minerals in sediments, generally reflect climatic changes, particularly in
tropical environments, with intense chemical weathering. In order to reconstruct the
paleoclimate of a Savanna ecosystem in the Amazon, fieldwork was carried out with the
opening of five trenches in soil under Savanna and Forest vegetation, each approximately 200
cm deep. In the resulting x-ray diffractograms, the occurrence of only kaolinite was observed
throughout the sampled profiles. The identification of gibbsite only in savanna soils, suggests
a strong weathering, favored by genetic factors of these soils. The kaolinite crystals observed
in Scanning Electron Microscope (SEM), present characteristic morphological aspects of the
mineral, showing themselves as pseudo-hexagonal, euhedral plates, stacked plates (booklets)
and with vermicular texture, in addition to being observed as fine aggregates under the quartz
crystals. With the occurrence of only kaolinite in these soils, it is possible to infer that there
were no significant changes in the climate and vegetation of this region.

MEMBROS DA BANCA:
Externo ao Programa - 2142681 - BRUNO APOLO MIRANDA FIGUEIRA
Externa ao Programa - 1339097 - FERNANDA SOUZA DO NASCIMENTO
Presidente - 2034627 - JULIO TOTA DA SILVA
Interno - 1549120 - RODRIGO DA SILVA