Banca de QUALIFICAÇÃO: LUZIA LINIANE DO NASCIMENTO SILVA
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.DISCENTE : LUZIA LINIANE DO NASCIMENTO SILVA
DATA : 12/07/2019
HORA: 10:00
LOCAL: Sala 2 - PPGG
TÍTULO:
Inter reef sedimentation on northeastern outer shelf environments of RN
PALAVRAS-CHAVES:
sedimentation; Açu Reef; isotopes; outer shelf
PÁGINAS: 31
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
SUBÁREA: Geologia
RESUMO:
Continental sheves are complex systems influenced by climatic changes and the input of terrigenous and carbonate sediments, affecting the antecedent morphology and forming new features. This work investigates sedimentation patterns and the distribution of reefs on the north of Rio Grande do Norte State, and its correlation with sea level variations, geology and the development of Açu Reefs. The data set consists of sedimentary samples, isotopes of oxygen (δ18O) and carbon (δ13C) of benthic foraminifera, satellite images, and sedimentary thin slides, and later, radiocarbon dating (14C) will be inserted from foraminifera and material carbonate and reefs. Statistical analyses were performed on the sediments through software GRADISTAT, in addition, mineralogical analyses were made by diffraction X-rays in bioclastic and siliciclastic facies. Preliminary results showed that differences in the sedimentation of the regions external to the reefs, inter-reefs and in the incised valley of the Açu river. Evidence of iron content in sediments indicates possible preservation of coastal sediments or indication of near terrigenous source area (i.e., Barreiras Formation or Tibau). The foraminifera suggests a season of warmer waters and upwelling on the shelf edge. Sediment samples and biogenetic reefs and beachrocks on the outer shelf are being prepared for radiocarbon dating (14C) and can provide detailed information on the development of the Açu Reefs and to refine the sea level curve.
MEMBROS DA BANCA:
Externa ao Programa - 277437 - MARCELA MARQUES VIEIRA
Interno - 2042405 - MOAB PRAXEDES GOMES
Externa à Instituição - NARELLE MAIA DE ALMEIDA - IFRN