Banca de DEFESA: VICTORIA MARIA DE ALMEIDA SANTOS CEDRAZ
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : VICTORIA MARIA DE ALMEIDA SANTOS CEDRAZ
DATA : 30/07/2019
HORA: 09:00
LOCAL: Auditório do DGEF
TÍTULO:
Joint inversion of receiver functions and surface wave dispersion in the Pantanal Wetlands
PALAVRAS-CHAVES:
Pantanal basin; Andean foreland bulge; Transbrasiliano Lineament; Receiver function; Surface-wave dispersion; Joint inversion.
PÁGINAS: 125
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:
The origin and evolution of the Pantanal Basin has been investigated through velocity-depth profiles developed from the joint inversion of receiver functions and surface-wave dispersion velocities at 32 broadband stations. The Pantanal Basin is a shallow and wide depression in South-Central Brazil that developed within the Andean foreland in response to loads and flexural bending of the South American plate. Our results reveal the existence of up to four different crustal types that correlate with surface geology: (i) crust of 35 km with VS < 4.0 km/s, under the basin and along the SW projection of the Transbrasiliano Lineament (TBL); (ii) crust of 45 km with VS > 4.0 km/s below 40 km depth, flanking the basin to the East and West; (iii) crust of 50-55 km with VS > 4.0 km/s below 40 km depth, flanking the basin to the North and South and along the TBL; and (iv) crust of 42.5-45.0 km with VS < 4.0 km/s in the neighboring Paraná Basin. Existing geodynamic models propose that the Pantanal Basin formed either in the backbulge of the flexural system or at the top of the flexural forebulge, due to extensional bending stresses that reactivated pre-existing faults in the shallow upper crust. We argue that the Pantanal Basin formed in a structurally weaker portion of the foreland crust that was affected by delamination and enhanced bending of the South American plate. Our findings do not allow for discrimination among the competing models, but suggest the TBL was critical in marking the location, origin and evolution of this basin.
MEMBROS DA BANCA:
Interno - 1451214 - ADERSON FARIAS DO NASCIMENTO
Presidente - 1863578 - JORDI JULIA CASAS
Externo à Instituição - VICTOR SACEK - USP