Constitution and significance of the Troodos sheeted complex
Por:
Desmet A., Lapierre H., Rocci G., Gagny Cl., Parrot J.-F., Delaloye M.
Publicada:
1 ene 1978
Resumen:
THE Troodos ophiolitic suite (Cyprus) has long been considered as a model of a piece of oceanic crust1-4 with its sheeted complex as the proof of accretion during Mesozoic times5,6. Using geochemical data, however, it has been suggested7 that the Troodos may have been formed in an island arc environment. Thus, a discussion has arisen on the origin of this ophiolite8-10. New fieldwork and detailed studies show that the Troodos sheeted complex consists of two main structurally well defined families of dykes, the first one partly produced by accretion, the second related to accretion and late fracturing of a magma chamber when spreading stopped. All the dykes are tholeiitic and four generations have been recognised: diabase, dolerite, picritic lamprophyre and basalt - this succession may be compared to the evolution of the Troodos pillow lavas11. New geo-chronological measurements reported here suggest that the emplacement of the sheeted complex started before 80 Myr, and confirm the existence of an active 'tethyan' ridge in middle cretaceous. Isochrone ageing show that greenschist fades metamorphism is also pre-Campanian. © 1978 Nature Publishing Group.
Filiaciones:
Desmet A.:
Laboratoire de Pétrologie, Université de Nancy I, Case Officielle 140, 54037 Nancy Cédex, France
Lapierre H.:
Laboratoire de Pétrologie, Université de Nancy I, Case Officielle 140, 54037 Nancy Cédex, France
Rocci G.:
Laboratoire de Pétrologie, Université de Nancy I, Case Officielle 140, 54037 Nancy Cédex, France
Gagny Cl.:
Laboratoire de Géologie Régionale (Pétrologie Structurale), Université de Nancy I, Case Officielle 140, 54037 Nancy Cédex, France
Parrot J.-F.:
S.S.C. de l'ORSTOM - Laboratoire de Géologie, 70-74 route d'Aulnay, 93140 Bondy, France
Delaloye M.:
Département de Minéralogie, Université de Geneve, 13 rue des Maraîchers, 1211 Geneve 4, Switzerland
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