0000000000400121

AUTHOR

E. M. Piccirillo

showing 8 related works from this author

Proterozoic dykes of Salvador and Ilhéus-Olivença areas: a geological geoghemical comparison

1991

Light nucleusIgneous rockIsotopeStable isotope ratioProterozoicAge estimationGeneral EngineeringGeochemistryIsotopes of argonRadiometric datingGeologyBoletim IG-USP. Publicação Especial
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Evidence of magmatic activity related to Middle Jurassic and Lower Cretaceous rifting from northeastern Brazil (Ceará-Mirim): K/Ar age, palaeomagneti…

1992

The Mesozoic magmatic activity in the easternmost part of NE Brazil (Ceara-Mirim) is mainly represented by two-pyroxene tholeiitic dykes; only few dykes have alkaline character. K/Ar ages and palaeomagnetism data indicate that Ceara-Mirim dykes are of Middle Jurassic (175-160 Ma) and Early Cretaceous (140-130 Ma) age. Both Middle Jurassic and Lower Cretaceous dykes have high incompatible-element concentrations and TiO2 with the lower contents generally confined to the Middle Jurassic dykes; rare tholeiitic dykes low in TiO2 and incompatible elements are present. Sr/1bNd isotopic and other chemical data do not support appreciable crustal contamination and in a 87Sr86Sr vs. 143Nd144Nd diagram…

BasaltgeographyIncompatible elementgeography.geographical_feature_categoryGeochemistryGeologyMantle (geology)CretaceousVolcanic rockPaleontologyIgneous rockGeochemistry and PetrologyOceanic crustMetasomatismGeologyChemical Geology
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Mesozoic mafic dyke swarm from Rio Ceará-Mirim (northeast Brazil)

1989

GeochemistryGeneral Earth and Planetary SciencesSwarm behaviourNortheast brazilMesozoicMaficPetrologyGeologyGeneral Environmental ScienceBoletim IG-USP. Série Científica
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Preliminary petrographic and geochemical considerations on the precambrian mafic dykes of the Ilhéus-Olivença area, Bahia

1989

PetrographyPrecambrianGeochemistryGeneral Earth and Planetary SciencesMaficPetrologyGeologyGeneral Environmental ScienceBoletim IG-USP. Série Científica
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La/Nb variation in Proterozoic and Mesozoic mafic dyke swarms in Brazil

1989

ProterozoicGeochemistryGeneral Earth and Planetary SciencesMesozoicMaficVariation (astronomy)GeologyGeneral Environmental ScienceBoletim IG-USP. Série Científica
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Tholeiitic dyke swarm from the Ponta Grossa Arch and genetic relationships to the Paraná flood volcanics (Brazil)

1989

Volcanic rockPaleontologygeographygeography.geographical_feature_categoryFlood mythGeneral Earth and Planetary SciencesSwarm behaviourArchGeologyGeneral Environmental ScienceBoletim IG-USP. Série Científica
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Mafic dykes of Salvador (State of Bahia, Brazil): geological and petrological characteristics

1989

GeochemistryGeneral Earth and Planetary SciencesMaficPetrologyGeologyGeneral Environmental ScienceBoletim IG-USP. Série Científica
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Potassic dyke swarm in the Sapucai Graben, Eastern Paraguay: Petrographical, mineralogical and geochemical outlines.

1992

Abstract The western side of the Parana Basin of Brazil extends to central Paraguay, where repeated and widespread magmatic activity developed from Lower Cretaceous to Oligocene, associated with late Mesozoic crustal extension trending NE-SW. In central Paraguay this trend is characterized by a zone of NW-SE normal faults which formed the Asuncion-Sapucai graben, up to 45 km wide and 200 km long, where alkaline rocks occur as volcanic domes, complexes, lava-flows and dykes. These rocks, 128 Ma aged, are dominantly potassic and ne-normative. A swarm of at least 200, mainley NW-SE trending, dykes occurs in the Sapucai region and seems to be formed by two main lineages: tephrite to phonolite (…

PhonoliteBasaltPargasiteAlkali basaltGeochemistryGeologyPeralkaline rockchemistry.chemical_compoundchemistryGeochemistry and PetrologyTephriteNephelineKaersutiteGeology
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