Seismic studies of the Brasília fold belt at the western border of the São Francisco Craton, Central Brazil, using receiver function, surface-wave dispersion and teleseismic tomography

Crustal thickness map of Brazil: Data compilation and main features

“…Crustal thickness estimates from other stations in central and northern Brazil were also compiled from Krüger et al (2002), Rosa et al (2012), Albuquerque et al (2011) and unpublished monographs such as Pedreschi (1989) and Costa (2005). The compiled studies report both crustal thickness (H) and Vp/Vs ratio (k) estimated with different techniques, such as the Hek stacking procedure of Zhu and Kanamori (2000), the waveform matching technique of Meijde et al (2003) and Lloyd et al (2010), the phase- (2004) and Assumpção et al (2004), and the joint inversion of receiver functions and surface-wave dispersion velocities of Julià et al (2000Julià et al ( , 2003. The joint inversion approach was utilized in Julià et al (2008) to obtain S-wave velocityedepth profiles under 13 stations in the Paraná Basin, and we have applied the same procedure to 18 additional stations in other areas to add new point constraints of crustal thickness to our final compilation (Table 1).…”

Basement depths in the Parecis Basin (Amazon) with receiver functions from small local earthquakes in the Porto dos Gaúchos seismic zone

“…The receiver function technique has been used successfully in Brazil for modeling deep structures such as the Moho discontinuity (Ammon et al, 1990;James et al, 1993;Assumpção et al, 2002Assumpção et al, , 2004Krüger et al, 2002;França and Assumpção, 2004;Dourado et al, 2007;Julià et al, 2008), discontinuities of 410 km and 670 km in the upper mantle transition zone (Liu et al, 2003;Bianchi, 2009) as well as shallow features like sediment thickness, particularly in the Paraná basin (An and Costa et al, 2006;Silva et al, 2008;Zevallos et al, 2009). …”

Evolução tectônica da margem ativa Neoproterozóica do Orógeno Gondwana Oeste na Província Borborema (NE-Brasil)

“…Deep crustal and lithospheric studies using seismic tomography (Assumpção et al, 2004, Feng et al, 2007 The Paraguay Belt (location in figure 9.3) is a typical fold-and-thrust belt located along the southeastern mar-gin of the Amazonian Craton (Alvarenga et al, 2000, Campanha et al, 2011. It is affected by tectonic deformation, which is almost imperceptible at the border of the craton, but increases up to tight isoclinal folds towards its inner areas.…”

“…In Mato Grosso do Sul State, several undeformed granitic plutons with ages between 550 Ma and 520 Ma , and references therein) have been encountered along the TB, which cut through the supracrustal rocks of the Paraguay Belt, as will be described later. In Goiás State, deep crustal and lithospheric seismic tomography (Assumpção et al, 2004;Feng et al, 2007) and deep seismic refraction and teleseismic receiver function investigations have been conducted at the location of a large positive Bouguer anomaly, corresponding to the surface exposure of the GMA. In this region, using group-velocity tomography and lithospheric s-velocity studies, Feng et al, (2007) demonstrated that there was a region of thinner lithosphere along the shear system.…”