dc.contributor |
Universitat de Barcelona |
dc.contributor.author |
Torró i Abat, Lisard |
dc.contributor.author |
Proenza Fernández, Joaquín Antonio |
dc.contributor.author |
Marchesi, C. |
dc.contributor.author |
García-Casco, A. |
dc.contributor.author |
Lewis, J.F. |
dc.date |
2017-03-07T14:37:40Z |
dc.date |
2019-02-16T06:10:24Z |
dc.date |
2017-02-16 |
dc.date |
2017-03-07T14:37:40Z |
dc.identifier.citation |
0024-4937 |
dc.identifier.citation |
667960 |
dc.identifier.uri |
http://hdl.handle.net/2445/108044 |
dc.format |
59 p. |
dc.format |
application/pdf |
dc.language.iso |
eng |
dc.publisher |
Elsevier B.V. |
dc.relation |
Versió postprint del document publicat a: https://doi.org/10.1016/j.lithos.2017.01.031 |
dc.relation |
Lithos, 2017, vol. 278-281, p. 255-273 |
dc.relation |
https://doi.org/10.1016/j.lithos.2017.01.031 |
dc.rights |
cc-by-nc-nd (c) Elsevier B.V., 2017 |
dc.rights |
info:eu-repo/semantics/openAccess |
dc.rights |
http://creativecommons.org/licenses/by-nc-nd/3.0/es |
dc.subject |
Geoquímica |
dc.subject |
Roques volcàniques |
dc.subject |
República Dominicana |
dc.subject |
Geochemistry |
dc.subject |
Volcanic rocks |
dc.subject |
Dominican Republic |
dc.title |
Petrogenesis of volcanic rocks from the Maimón Formation (Dominican Republic): Geochemical record of the nascent Greater Antilles paleo-arc |
dc.type |
info:eu-repo/semantics/article |
dc.type |
info:eu-repo/semantics/acceptedVersion |
dc.description.abstract |
Metamorphosed basalts, basaltic andesites, andesites and plagiorhyolites of the Early Cretaceous, probably pre-Albian, Maimón Formation, located in the Cordillera Central of the Dominican Republic, are some of the earliest products of the Greater Antilles arc magmatism. In this article, new whole-rock element and Nd-Pb radiogenic isotope data are used to give new insights into the petrogenesis of the Maimón meta-volcanic rocks and constrain the early evolution of the Greater Antilles paleo-arc system. Three different groups of mafic volcanic rocks are recognized on the basis of their immobile element contents. Group 1 comprises basalts with compositions similar to low-Ti island arc tholeiites (IAT), which are depleted in light rare earth elements (LREE) and resemble the forearc basalts (FAB) and transitional FAB-boninitic basalts of the Izu-Bonin-Mariana forearc. Group 2 rocks have boninite-like compositions relatively rich in Cr and poor in TiO2. Group 3 comprises low-Ti island arc tholeiitic basalts with near-flat chondrite-normalized REE patterns. Plagiorhyolites and rare andesites present near-flat to subtly LREE-depleted chondrite normalized patterns typical of tholeiitic affinity. Nd and Pb isotopic ratios of plagiorhyolites, which are similar to those of Groups 1 and 3 basalts, support that these felsic lavas formed by anatexis of the arc lower crust. Geochemical modelling points that the parental basic magmas of the Maimón meta-volcanic rocks formed by hydrous melting of a heterogeneous spinel-facies mantle source, similar to depleted MORB mantle (DMM) or depleted DMM (D-DMM), fluxed by fluids from subducted oceanic crust and Atlantic Cretaceous pelagic sediments. Variations of subduction-sensitive element concentrations and ratios from Group 1 to the younger rocks of Groups 2 and 3 generally match the geochemical progression from FAB-like to boninite and IAT lavas described in subduction-initiation ophiolites. Group 1 basalts likely formed at magmatic stages transitional between FAB and first-island arc magmatism, whereas Group 2 boninitic lavas resulted from focused flux melting and higher degrees of melt extraction in a more mature stage of subduction. Group 3 basalts probably represent magmatism taking place immediately before the establishment of a steady-state subduction regime. The relatively high extents of flux melting and slab input recorded in the Maimón lavas support a scenario of hot subduction beneath the nascent Greater Antilles paleo-arc. Paleotectonic reconstructions and the markedly depleted, though heterogeneous character of the mantle source, indicate the rise of shallow asthenosphere which had sourced mid-ocean ridge basalts (MORB) and/or back-arc basin basalts (BABB) in the proto-Caribbean domain prior to the inception of SW-dipping subduction. Relative to the neighbouring Aptian-Albian Los Ranchos Formation, we suggest that Maimón volcanic rocks extruded more proximal to the vertical projection of the subducting proto-Caribbean spreading ridge. |