@Article{PadilhaVitoAntuPádu:2015:ImThCr,
author = "Padilha, Antonio Lopes and Vitorello, {\'{\I}}caro and Antunes,
C{\'a}ssio Esp{\'{\i}}ndola and P{\'a}dua, Marcelo Banik de",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas
Espaciais (INPE)}",
title = "Imaging three-dimensional crustal conductivity structures
reflecting continental flood basalt effects hidden beneath thick
intracratonic sedimentary basin",
journal = "Journal of Geophysical Research",
year = "2015",
volume = "120",
number = "7",
pages = "4702--4719",
month = "July",
keywords = "continental flood basalts, electromagnetic induction, large
igneous provinces, Paran{\'a} Basin, three-dimensional
conductivity structure.",
abstract = "A large-scale array of long-period magnetic data and a
deep-probing magnetotelluric profile were recorded in the
intracratonic Paran{\'a} sedimentary basin in central eastern
South America, which presents a thick and extensive
sedimentary-magmatic sequence that allows its basement to be
investigated only by indirect methods. Integration of the results
from both methods showed that the crust beneath the basin presents
several quasi-linear highly conductive channeled zones with
limited lateral extent, in coincidence with some of the main
tectonic structures recognized at the surface, and a moderate but
pervasive lithosphere conductivity enhancement beneath its central
part. Upward movement of CO2-bearing volatiles and magmas
precipitating highly conducting mineral phases along discrete
subvertical fault zones that served as feeder conduits for Early
Cretaceous voluminous continental flood basalts was a likely
process responsible for the localized conductivity enhancements.
Correlation between some of the linear conductive zones and
elongated magnetic anomalies and between the maximum depth
occurrence of most of these conductive anomalies and the Curie
depth at which crustal rocks lose their magnetism gives strong
support to interconnected iron oxides (especially magnetite) and
iron sulfides (such as pyrrhotite) as the main conductive sources.
The moderate bulk conductivity increase in the crust and upper
mantle beneath the central part of the basin is unexpected for a
postulated cratonic basement and is tentatively associated with
impregnation of the lithosphere by conducting minerals related
either to widespread tectonic events in the Ordovician or Late
Precambrian or to dispersed magmatic residues of an Early
Cretaceous magma differentiation contaminating the entire
lithosphere.",
doi = "10.1002/2014JB011657",
url = "http://dx.doi.org/10.1002/2014JB011657",
issn = "0148-0227 and 2156-2202",
language = "en",
urlaccessdate = "27 abr. 2024"
}