Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/163278
Title: High-pressure greenschist to blueschist facies transition in the Maimón Formation (Dominican Republic) suggests mid-Cretaceous subduction of the Early Cretaceous Caribbean Arc
Author: Torró i Abat, Lisard
García Casco, A.
Proenza Fernández, Joaquín Antonio
Blanco-Quintero, Idael Francisco
Guitérrez-Alonso, G.
Lewis, J. F.
Keywords: Fàcies (Geologia)
Cretaci
Subducció
República Dominicana
Facies (Geology)
Cretaceous Period
Subduction
Dominican Republic
Issue Date: Dec-2016
Publisher: Elsevier B.V.
Abstract: The Maimón Formation (Cordillera Central, Dominican Republic) is formed of metamorphosed bi-modal mafic-felsic volcanic rocks and sedimentary horizons of Early Cretaceous age deposited in the forearc of the nascent Caribbean island arc. Two structural-metamorphic zones depict an inverted metamorphic gradient: the Ozama shear zone, which records intense mylonitic and phyllonitic deformation and ubiquitous metamorphic recrystallization, tectonically overlies the much less deformed and variably recrystallized rocks of the El Altar zone. The presence of ferri-winchite and high-Si phengite, first reported in this paper, in the peak metamorphic assemblage of rocks of the Ozama shear zone (actinolite + phengite + chlorite + epidote + quartz + albite ± ferri-winchite ± stilpnomelane) point to subduction-related metamorphism. Pseudosection calculations and intersection of isopleths indicate peak metamorphic conditions of ~ 8.2 kbar at 380 °C. These figures are consistent with metamorphism in the greenschist/blueschist facies transition, burial depths of ~ 25-29 km and a thermal gradient of ~ 13-16 °C/km. Our new data dispute previous models pointing to metamorphism of Maimón rocks under a steep thermal gradient related to burial under a hot peridotite slice. Instead, we contextualize the metamorphism of the Maimón Formation in a subduction scenario in which a coherent slice of the (warm) Early Cretaceous forearc was engulfed due to intra-arc complexities and regional-scale-driven tectonic processes operating in the late Early Cretaceous. Integration of our findings with previous studies on metamorphic complexes in Hispaniola suggests that a major tectonic event affecting the whole arc system took place at c. 120-110 Ma.
Note: Versió postprint del document publicat a: https://doi.org/10.1016/j.lithos.2016.10.026
It is part of: Lithos, 2016, vol. 266-267, p. 309-331
URI: http://hdl.handle.net/2445/163278
Related resource: https://doi.org/10.1016/j.lithos.2016.10.026
ISSN: 0024-4937
Appears in Collections:Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)

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