Banca de QUALIFICAÇÃO: IGOR LEONARDO GUERRA GALVÃO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : IGOR LEONARDO GUERRA GALVÃO
DATA : 11/07/2016
HORA: 09:00
LOCAL: Sala 01 PPGG
TÍTULO:

STUDY OF THE RIO GRANDE RISE BASED ON GEOPHYSICAL METHODS AND SATELLITE DATA

PALAVRAS-CHAVES:

Rio Grande Rise; Cruzeiro do Sul Lineament; South Atlantic Ocean; Potential Methods; Global Geophysical datas; Structural framework; Ocean Fracture Zones.

PÁGINAS: 32
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

The Rio Grande Rise (RGR) is a large volcanic plateau, formed from the intense magmatic activity associated with Pluma Tristan da Cunha - Gough Islands, which modifies considerably the planar layering the ocean abyssal area in the western portion of the South Atlantic. The RGR is cutted by a rift NW-SE direction (called the Cruzeiro do Sul), which has developed into an accommodation zone to extensional efforts from the expansion of the ocean floor, and has about 30 km of width and depth more 2,000 m. The survey consists of a regional geophysical mapping of elevation based on gravity and magnetic data from global databases produced by partnerships between research institutions around the world. Preliminary interpretations show that the elevation is represented by bouguer gravity anomalies values of 280 mgal order, reaching a value of 445 mgal the edges of the segments west and east elevation. These values indicate a mass deficiency compared to the adjacent regions, which have high levels of bouguer anomalies and are associated with the distribution of oceanic basins of Brazil and Argentina. The values of these anomalies bouguer ocean basins range from 480 mgal, in the more distal portions of the main Depocenter basins, and 545 mgal, in the deeper areas of the same. The Cruzeiro do Sul lineament is represented by an extensive negative free-air anomaly (-130 mgal). In addition, the magnetic data allowed delineate the continuity, towards the Brazilian margin, some of the many of ocean fractures zones that cut the elevation region and are difficult to understand, in the gravimetrics and bathymetrics datas, in areas with large sedimentary thicknesses or where there are major physiographic features the masks, as in the RGR region. These data demonstrate numerous reactivations of pre-existing transformants faults after the formation of the rift, as many of these fracture zones coincide with inflections along the long rift that has formed on the RGR.

MEMBROS DA BANCA:
Presidente - 1315614 - DAVID LOPES DE CASTRO
Interno - 350640 - FRANCISCO HILARIO REGO BEZERRA
Interno - 349684 - WALTER EUGENIO DE MEDEIROS