The main mafic dyke swarms of the São Francisco craton range in age from Late Archean to the Early Neoproterozoic, and record extensional and transpression tectonic events. The Uauá and Lavras regions include norite (2.73 and 2.66 Ga) and tholeiite swarms (2.62 and 1.97 Ga) respectively. Other swarms are made up of tholeiites: Paraopeba (2.10 Ga), Pará de Minas (1.71 Ga), Curaçá and Chapada Diamantina (1.5 Ga), Diamantina (0.93 Ga) and Salvador-Olivença (0.92 Ga). Geochemical and Sr–Nd isotopic data indicate variable scales of mantle heterogeneity, caused by recurrent metasomatic effects since Archean times. The main processes are attributed to the action of slab fluids from recycling of oceanic crust and overlying sediments on the sub-lithospheric mantle in continental settings, and by upwelling of OIB-like material. These processes are consistent with the protracted geologic history of the country rocks, given by episodic juvenile accretion and successive continental amalgamations from Archean to ca. 2.0 Ga. The adopted mixing geochemical model permits to evaluate the variation range of N-MORB melts, OIB and slab fluids and melts, which are considered to represent the main components of the parental mantle composition of the studied dykes.

Mafic Dykes: Petrogenesis and Tectonic Inferences / Girardi, Vicente A. V.; Teixeira, Wilson; Mazzucchelli, Maurizio; de Oliveira, Elson P.; Corrêa da Costa, Paulo C.. - STAMPA. - (2016), pp. 145-169. [10.1007/978-3-319-01715-0_8]

Mafic Dykes: Petrogenesis and Tectonic Inferences

MAZZUCCHELLI, Maurizio;
2016

Abstract

The main mafic dyke swarms of the São Francisco craton range in age from Late Archean to the Early Neoproterozoic, and record extensional and transpression tectonic events. The Uauá and Lavras regions include norite (2.73 and 2.66 Ga) and tholeiite swarms (2.62 and 1.97 Ga) respectively. Other swarms are made up of tholeiites: Paraopeba (2.10 Ga), Pará de Minas (1.71 Ga), Curaçá and Chapada Diamantina (1.5 Ga), Diamantina (0.93 Ga) and Salvador-Olivença (0.92 Ga). Geochemical and Sr–Nd isotopic data indicate variable scales of mantle heterogeneity, caused by recurrent metasomatic effects since Archean times. The main processes are attributed to the action of slab fluids from recycling of oceanic crust and overlying sediments on the sub-lithospheric mantle in continental settings, and by upwelling of OIB-like material. These processes are consistent with the protracted geologic history of the country rocks, given by episodic juvenile accretion and successive continental amalgamations from Archean to ca. 2.0 Ga. The adopted mixing geochemical model permits to evaluate the variation range of N-MORB melts, OIB and slab fluids and melts, which are considered to represent the main components of the parental mantle composition of the studied dykes.
2016
6-dic-2016
São Francisco Craton, Eastern Brazil
Heilbron, Monica; Cordani, Umberto G.; Alkmim, Fernando F.
9783319017143
Springer International Publishing
GERMANIA
Mafic Dykes: Petrogenesis and Tectonic Inferences / Girardi, Vicente A. V.; Teixeira, Wilson; Mazzucchelli, Maurizio; de Oliveira, Elson P.; Corrêa da Costa, Paulo C.. - STAMPA. - (2016), pp. 145-169. [10.1007/978-3-319-01715-0_8]
Girardi, Vicente A. V.; Teixeira, Wilson; Mazzucchelli, Maurizio; de Oliveira, Elson P.; Corrêa da Costa, Paulo C.
File in questo prodotto:
File Dimensione Formato  
314734_1_En_8_Chapter_Author.pdf

Accesso riservato

Descrizione: Uncorrected proof
Tipologia: Versione dell'autore revisionata e accettata per la pubblicazione
Dimensione 1.16 MB
Formato Adobe PDF
1.16 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

Licenza Creative Commons
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1121580
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 17
social impact