The petrogenesis of tholeiitic diabases in eastern Parnaíba Basin: evidence for geochemical heterogeneities in the subcontinental lithospheric mantle in NE Brazil

Abstract

The sedimentary rocks within the Paleozoic Parnaiba basin in NE Brazil

Role of basaltic magmatism within the Parnaíba cratonic basin, NE Brazil

“…Sardinha basaltic melting is coeval with, and of similar composition to, Paraná (Serra Geral) melting from the southern part of Brazil (Bellieni et al, 1990;Baksi & Archibald, 1997). A northsouth alignment of outcrops from the Parnaíba basin might be caused by minor amounts of rifting parallel to the South Atlantic margin or by pre-existing weaknesses along the Transbrasiliano lineament (Figure 1a n/a n/a n/a n/a n/a n/a n/a n/a LOI (%) 0.25 n/a n/a n/a n/a n/a n/a n/a n/a (Fodor et al, 1990;de Min et al, 2003;Ernesto et al, 2003); open circles show samples from Mosquito Formation that have insufficient trace element data or are too evolved for our purposes (Bellieni et al, 1990;Fodor et al, 1990;de Min et al, 2003;Merle et al, 2011); solid diamonds show samples from Sardinha Formation used in this study (Fodor et al, 1990;Ernesto et al, 2003;da Silva et al, 2017); open diamonds show samples from Sardinha Formation that have insufficient trace element data or are too evolved for our purposes (Bellieni et al, 1990;Fodor et al, 1990;de Min et al, 2003;Ernesto et al, 2003); solid squares show samples from putative Sardinha Formation used in this study (da Silva et al, 2017); solid/dashed line shows Transbrasiliano lineament (Bizzi et al, 2003). (b) Geological map of Parnaíba Basin modified after Bizzi et al (2003).…”

Geochemical characterization of the Equatorial Atlantic Magmatic Province and its correlation with other magmatic events related to the South Atlantic Opening

“…Although sills are mapped from north to south along the entire eastern side of the basin, the groundbreaking works have restricted the sampling to a small central area ignoring much of the geographic (and maybe geochemical) representativeness of this magmatism. Supported by resources of the oil-gas industry, some scientific papers were recently published dealing on the geochemical aspects of these eastern sills (Silva et al, 2017;Oliveira, et al, 2018;Heilbron et al, 2018;Miloski et al, 2019Miloski et al, , 2020. Despite the merits, important sampling gaps persist, especially in southeastern areas.…”