Cinturones metamórficos ofiolíticos de Cuba
- A. Garcia-Casco 1
- G. Millán 2
- M.A. Iturralde-Vinent 3
- K. Núñez Cambra 2
- Y. Rojas-Agramonte 4
- C. Lázaro 1
- F. Blanco-Quintero 5
- J. Cárdenas-Párraga 1
- J.A. Proenza 6
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1
Universidad de Granada
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- 2 Instituto de Geología y Paleontología
- 3 Academia de Ciencias de Cuba
- 4 Universität of Kiel
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5
Universitat d'Alacant
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6
Universitat de Barcelona
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ISSN: 1576-5172
Year of publication: 2021
Issue Title: X Congreso Geológico de España
Issue: 18
Pages: 1053
Type: Article
More publications in: Geotemas (Madrid)
Abstract
Metamorphism affects parts of all types of lithospheric sections represented in the Mesozoic-Tertiary Cuban accretionary orogen. It was triggered by major geodynamic processes, including formation of the oceanic island-arc, oceanic and passive margin subduction, oceanic arc terrane accretion, obduction of ophiolitic units and arc-continent collision, which led to the formation of metamorphic belts with varied age and P/T ratio. Two of them, closely related to the ophiolitic units, formed synchronously and define a paired metamorphic belt along ca. 1200 km. It is characterized by tectonic blocks in serperti- nitic matrix mélanges that include: a) low P greenschist to near-granulite facies rocks developed under static conditions as a result of ocean-floor metamorphism of suprasubduction oceanic lithosphere and b) eclogite, garnet amphibolite and, locally, jadeitite, that represent fragments of the subduction channel containing subducted oceanic and arc lithospheres. The formation of this paired belt was triggered by subduction initiation at ca. 135 Ma. Younger low- and high-P blocks within the mélanges attest for the long-lasting activity (135-70 Ma) of the corresponding subduction system. Metamorphic soles below ophiolitic units and green/blueschist arc-related units (Cuba Oriental) relate to a new subduction initiation event in the back- arc at ca. 85 Ma while the main Caribbean subduction system was still active.