Banca de DEFESA: Thales Lúcio Santos da Silva

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Thales Lúcio Santos da Silva
DATE: 31/08/2022
TIME: 10:00
LOCAL: Remotamente
TITLE:
KEY WORDS:

Black Shale; Codó Formation; Ipubi Formation; Geochronology; Paleoen-vironment; Paleogeography

PAGES: 167
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

The Codó (São Luís-Grajaú Basin) and Ipubi (Araripe Basin) formations, which have black shale and evaporites sequences, have been correlated because of their fossil and lithology contents. However, geochemistry research has not been used to corre-late them in terms of paleoenvironment, age of deposition and paleogeographic set-ting. Using geochemistry (organic, inorganic and isotope) herein is presented those geologic topics of the black shale from Codó and Ipubi formation. These rocks depos-ited in suboxic-oxic conditions (V/Cr < 2; COT/NT > 5; δ15Ntotal = 3,7-6,9 ‰), hot and humid climate (Rb/Sr < 1; Sr/Cu < 5; high Fe/Mn; negative δ13Corg) and stratified body because of the paleosalinity conditions (Sr/Ba < 0,2). Besides that, the black shales have terrigenous to marine organic matter in both basins. From Re-Os geochronology, herein is presented an age of 119,52 ± 2,51 Ma (Late Barremian-Early Aptian) to black shales of Codó Formation (in Grajaú Basin), prior to the OAE1a. Furthermore, those rocks are correlated to Ipubi Formation black shales, which have an age of 122,61 ± 3,5 Ma (Late Barremian-Early Aptian). Mixing all data herein, it could infer that: (i) the marine ingression from the Tethys Sea was through by the São Luís Basin, but that ingression does not cross to the both Grajaú and Araripe basins because of the Ferrer-Urbano Santos Arc; (ii) the Araripe Basin was affected by the marine ingression from Potiguar Basin, however that ingression only have place in the SW part of the basin because, in that time, there was a topographically lowered platform in that area and in the NE part of the basin there were horst and lineaments which blocked the marine ingression.

BANKING MEMBERS:
Presidente - 1320828 - JOAO ADAUTO DE SOUZA NETO
Interno - 3089741 - CLAUS FALLGATTER
Interno - 1133907 - VIRGINIO HENRIQUE DE MIRANDA LOPES NEUMANN
Externa à Instituição - JULIANA CHARÃO MARQUES - UFRGS
Externo à Instituição - RENÉ RODRIGUES - UERJ