Banca de DEFESA: LUCAS BARBOSA CABRAL

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCAS BARBOSA CABRAL
DATE: 04/09/2026
TIME: 14:30
LOCAL: Auditorio do CCET
TITLE:

MORPHOLOGICAL AND SEDIMENTARY CHARACTERIZATION OF THE NNW  REGION OF THE SÃO PEDRO AND SÃO PAULO ARCHIPELAGO

KEY WORDS:

Marine Geomorphology; Multibeam Bathymetry; São Paulo Fracture Zone (SPFZ);  Volcanic Cones, Backscatter

PAGES: 76
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

The São Pedro and São Paulo Archipelago (SPSPA), in the Equatorial Atlantic, constitutes a unique  exposure of ultramafic rocks from the upper mantle. This work presents the geomorphological and  acoustic characterization of an area of approximately 1,800 km² located to the north-northwest of the  archipelago, with depths ranging from -170 m to -4131 m. The data were acquired using the  Kongsberg EM 122 multibeam echosounder during the QUAKES & WHALES project expedition,  and were processed using CARIS HIPS and SIPS and QGIS software. Six main morphological units  were mapped: Plains, Hills, Basins, Ramps, the Peridotite Chain (CPSPSP), volcanic edifices, and  the FT1 fault. The relief exhibits strong tectonic control with morphostructural lineaments  predominantly oriented in the NNE–SSW and ENE–WSW directions. The FT1 fault, with a length of  28 km, stands out as the main divider, separating the rugged basement domain to the south from the  organized basins to the north. The analysis of acoustic backscatter revealed three main domains:  Class I (high intensity, -20 to 3 dB; ~20% of the area), associated with peridotite outcrops and exposed  ridges; Class II (medium intensity, -32 to -20 dB; ~45%), corresponding to partially covered transition  surfaces; and Class III (low intensity, -56 to -32 dB; ~35%), dominating basins and deep plains that  act as depocenters for unconsolidated sediments. It is concluded that the configuration of the seafloor  is the result of mantle exhumation, localized volcanism, and sedimentary processes controlled by  gravity and the dynamics of deep currents.

COMMITTEE MEMBERS:
Interno - 1451214 - ADERSON FARIAS DO NASCIMENTO
Presidente - 2218779 - HELENICE VITAL
Externo à Instituição - VICTOR HUGO ROCHA LOPES - SGB