Banca de DEFESA: Luis Gomes Carvalho

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Luis Gomes Carvalho
DATE: 16/09/2022
TIME: 08:30
LOCAL: Sala de videoconferência do IGD
TITLE:

Stratigraphic and Structural Compartmentation of The Urucuia Aquifer System as a Water Resources Management Tool in the Western Region of Bahia State, Brasil.

KEY WORDS:

Sanfranciscan Basin, Rio Preto Belt, Transbrasiliano Lineament, Foreland Basin, Sinkhole, Geostatistic, Digital Elevation Model, Morphotectonic.

PAGES: 176
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

This thesis aims to study the structuring and evolution of the Urucuia Sub-Basin, emphasizing its central and northern portions, as well as adding information from the overlap region of the Sanfranciscan Basin to the Parnaíba Basin, a common area located between the Alto do São Francisco and the Transbrasiliano Lineament. The Urucuia Sub-Basin comprises the Urucuia Aquifer System, an important Brazilian aquifer that covers 65% of the western region of the State of Bahia and extends in smaller parts to the states of Piauí, Tocantins, Goiás and Minas Gerais. To meet the proposed objective, three papers were purposed, presenting: i) a review and update of morphotectonics structures generated by reactivations of cratonic blocks with records from neoproterozoic to Holocene that gave rise to the depression responsible for the installation and segmentation of the Sanfranciscan Basin and the neotectonic reactivations that fractured the siliceous rocks of the Urucuia Group; ii) potentiometric map obtained with the application of interpolation by Ordinary Kriging in which 4 hydrogeological dividers responsible for the subdivision of the Central Urucuia System into hydrogelogical sub-basins were identified; iii) shallow sinkholes that predominate in the northern part of the Urucuia Sub-Basin causing accidents with vehicles, machines/implements and restricting areas to cultivation, which were associated with the evolution of underground tubes that form at the interface of the oxisols of the Chapadão Formation with the siliceous and intensely fractured rocks of the Serra das Araras Formation located in the scope of the Rio Preto Lineament, and iv) deep abatement processes that generate large depressions mapped in the region under the influence of the Rio Preto Belt and other minor depressions in the Alto do Rio Grande region, related respectively to the tectonic reactivations of extensional-extensional duplexes and the transport of friable sediments of the Posse Formation as well as the dissolution of the carbonate rocks of the Bambuí Group, giving rise to the basins that generate the collapse of the eocretaceous to Holocene sediments. The geophysical data integrated with the information derived from geoprocessing and field show that the deposition in the Urucuia Sub-Basin has always controlled by the structuring of the basement, with reactivations and accommodations of existing features since the Proterozoic. The neotectonic manifestations evidenced in the northern part of the Sanfranciscan Basin are susceptible to increase frequency when associated with the compressional stress related to the expansion of the Mesoatlantic chain and the upheaval of the Andean chain transmitted by the discontinuities of the basement that converge to its north-northwest portion marked by the Tocantins-Araguaia, Transbrasiliano, Senador Pompeu, Patos and Pernambuco lineaments. These results confirm the existence of hydrogeological discontinuities in the Central Urucuia Aquifer System associated with morphotectonics and allow the correlation of surface and underground morphology regionally based on the potentiometric map, contributing to a better definition of actions related to the management of water resources. The determination of flow systems in compartments is important for the future management of the Urucuia Aquifer System, so that the compartments and hydrogeological dividers, together with the different subtypes of aquifers should be considered in the management processes, with the application of different actions for each aquifer and its compartment. The coluvium-alluvial coverage of the Chapadão Formation has shown collapsible behavior, which favors the occurrence of evident abatements in agricultural areas and on roads. The presence of siliceous levels in the Urucuia Aquifer is important, as it can define sections of the aquifer with fractured or double porosity behavior and also increases the occurrence of sinkhole abatements that have become more frequent.

BANKING MEMBERS:
Interna - 3167909 - ADALENE MOREIRA SILVA
Externo à Instituição - GERSON CARDOSO DA SILVA JUNIOR - UFRJ
Presidente - 1170677 - JOSE ELOI GUIMARAES CAMPOS
Externa à Instituição - Márcia Tereza Pantoja Gaspar
Externo ao Programa - 1685116 - WELITOM RODRIGUES BORGES