Banca de DEFESA: LAVINIA DA CRUZ BARBALHO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LAVINIA DA CRUZ BARBALHO
DATE: 27/05/2022
TIME: 08:30
LOCAL: videoconferência https://www.youtube.com/c/PPGGUFRNTransmiss%C3%A3odeBancas
TITLE:

Surface and Subsurface Geomorphological Mapping of the Parnaíba River Delta Tidal Channel System (Northeast Brazil) as Indicator of its Holocenic Evolution

 

KEY WORDS:

Parnaíba River Delta; Tidal channels; Remote sensing; High-resolution reflection seismic

PAGES: 90
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

The Parnaíba River Delta (PRD) is located on the Equatorial Margin of Brazil. The PRD consists of a wave-dominated delta with tidal influence, representing a rare example of a depositional system that preserves features in natural state. Remote sensing data (radar data from Alos Palsar and Landsat 8 images) coupled with high-resolution reflection seismic aimed to develop an altimetric and geomorphologic map of the PRD, as well as a seismic analysis of tidal channel system of the western portion of PRD. Based on the compilation of digital image processing procedures and concepts of sequence stratigraphy and seismostratigraphy, the present work aimed to expand the Holocene evolution of this delta by correlating surface and subsurface features. The conversion of ellipsoidal height to orthometric height was done to the Alos Palsar radar data and the statistical analysis of spectral bands constrained the most effective RGB compositions to identify fluvial-lacustrine plains, paleodunes, mangrove, beaches and recent dunes. As results, altimetric and geomorphological simplified maps were developed. The seismic analysis was done through the description and analysis of three reflection seismic lines on the western side of the PRD. The following criteria was considered: reflector patterns, limit surfaces, paleochannel morphology and filling patterns. In the results eight types of seismic facies (four variations of parallel to subparallel reflectors, as well chaotic, oblique prograding, wavy and translucent), two paleochannel morphologies (U and V), five types of filling patterns (onlap, prograding, chaotic, complex and diverging) and two seismostratigraphic units. The analysis and integration of the different information allows us to propose three stages of sea level for the interpreted data set. From the base to the top, they are: low sea level, transgressive and high sea level. The present work consists of a pioneer initiative on the PRD region, since previous works correlating seismostratigraphy and high-resolution reflection seismic were performed only on the offshore portion of the PRD. The results contributed to the advance of the knowledge regarding the geological evolution of the coastal sector of the Equatorial margin that is still poorly understood.

BANKING MEMBERS:
Presidente - 2218779 - HELENICE VITAL
Externa à Instituição - MARY LUCIA DA SILVA NOGUEIRA - UFOP
Externa à Instituição - NARELLE MAIA DE ALMEIDA - UFC