Late Jurassic Continental Flood Basalt doleritic dykes in north-western Cuba: remnants of the Gulf of Mexico opening.

Détails

ID Serval
serval:BIB_3EC8A8138E47
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Late Jurassic Continental Flood Basalt doleritic dykes in north-western Cuba: remnants of the Gulf of Mexico opening.
Périodique
Bull. soc. geol. fr.
Auteur(s)
J. Allibon, H. Lapierre, F. Bussy, M. Tardy, E. M. Cruz Gàmez, F. Senebier. 
Statut éditorial
Publié
Date de publication
2008
Volume
179
Numéro
5
Pages
445.452
Résumé
Accreted terranes, comprising a wide variety of Late Jurassic and Early Cretaceous igneous and sedimentary rocks are an important feature of Cuban geology. Their characterization is helpful for understanding Caribbean paleogeography.
The Guaniguanico terrane (Western Cuba) is formed by upper Jurassic platform sediments intruded by microgranular dolerite dykes. The geochemical characteristics of the dolerite whole rock samples and their minerals (augitic clinopyroxene, labradorite and andesine) are consitent with a tholeiitic affinity. Major and trace element concentrations as well as Nd, Sr and Pb isotopes show that these rocks also have a continental affinity. Sample chemistry indicates that these lavas are similar to a low Ti-P2O5 (LTi) variety of continental flood basalts (CFB) similar to the dolerites of Ferrar, derived from mixing of a lithospheric mantle source and an asthenopheric component similar to E-MORB with minor markers of crustal contamination and sediment assimilation. However, the small quantity of magmatic rocks related to this event, similarly to Ferrar (Tasmania), Antarctica and Siberia differs from other volumetrically important CFB occurrences such as Parana and Deccan.
These dolerites are dated 165-150 Ma and were emplaced during the separation of the Yucatan block from South America. They could in fact be part of the Yucatan-South America margin through which the intrusive system was emplaced and which was later accreted to the Cretaceous arc of central Cuba and to the Palaeogene arc of eastern Cuba. These samples could therefore reflect the pre-rift stage between North and South America and the opening of the Gulf of Mexico.
Mots-clé
dolerite dykes, Upper Jurassic, continental flood basalts, geochemistry, Cuba.
Création de la notice
21/08/2008 7:32
Dernière modification de la notice
20/08/2019 13:35
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