Provenance of sandstones in the Parnaíba Basin through detrital zircon geochronology
M. H. B. M. Hollanda, A. M. Góes, F. A. Negri, 2018. "Provenance of sandstones in the Parnaíba Basin through detrital zircon geochronology", Cratonic Basin Formation: A Case Study of the Parnaíba Basin of Brazil, M. C. Daly, R. A. Fuck, J. Julià, D.I.M. MacDonald, A. B. Watts
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This paper obtains numerous U–Pb detrital zircon ages obtained from the Paleozoic–Triassic sandstones of the Parnaíba Basin. The resulting spectra enable us to distinguish three common age populations: Paleoproterozoic, Stenian–Tonian (mainly between 1100 and 900 Ma) and Late Neoproterozoic. Minor contributions are observed from Archean, Paleozoic (mainly Cambrian) and Mesoproterozoic sources. Differences are only highlighted by variances in the relative abundances of each age population within the stratigraphic units. The presence of metamorphic phases, schists clasts and some diagnostic heavy minerals suggest that the Neoproterozoic mobile belts to the east and west of the basin are potential source areas. The erosion of metasedimentary rocks exposed in these provinces could explain the Paleoproterozoic and Stenian–Tonian age populations found in the sandstones. The Late Neoproterozoic ages, in turn, are not relevant in the metasedimentary sequences, requiring that the voluminous granitic magmatism mainly exposed in the Borborema Province had directly participated as a primary source of the detritus. The maintenance of common age spectra leads to two (not exclusive) hypotheses: the long-term denudation of the source areas and/or intrabasinal recycling, which can be considered in future investigations on the sedimentary and tectonic evolution of the Parnaíba Basin.
Supplementary material: The U–Pb data for detrital zircon grains of the sandstones of the Parnaíba Basin is available at https://doi.org/10.6084/m9.figshare.c.4129214
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Cratonic Basin Formation: A Case Study of the Parnaíba Basin of Brazil
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Cratonic basins are large, distinctive features of the continental crust. They are preferentially developed on thick continental lithosphere, are typically sub-circular in shape and subside over periods of hundreds of millions of years. They are also endowed with significant resources. However, in spite of their location in continental interiors and often well-known geology, the subsidence driving mechanism and tectonic setting of these basins remains controversial.
This volume presents both lithospheric and basin scale datasets acquired specifically to interrogate the tectonic process of cratonic basin formation. Focused on the Silurian to Triassic Parnaíba cratonic basin of Brazil, the papers discuss the results of a multidisciplinary basin analysis project comprising new geophysical, geological and geochemical data. This unique dataset enables the characterization of the lithospheric crust and mantle beneath the Parnaíba Basin, constrains the detailed evolution of the basin itself, and enables comparisons with cratonic basins globally. Several convergent themes emerge providing new and powerful constraints for models of the driving mechanisms of these enigmatic basins.