The Discovery of the Romero VMS Deposit and Its Bearing on the Metallogenic Evolution of Hispaniola during the Cretaceous
Metadatos
Afficher la notice complèteAuteur
Torró, Lisard; Proenza, Joaquín A.; Espaillat, Julio; Belén-Manzeta, Albert Joan; Román-Alday, María Clara; Amarante, Alberto; González, Norverto; Espinoza, Jorge; Román-Alpiste, Manuel Jesús; Nelson, Carl E.Editorial
MDPI
Materia
VMS Caribbean Greater Antilles Intra-oceanic island-arc Metallogenic evolution Dominican Republic
Date
2018-11-06Referencia bibliográfica
Torró, L. [et al.]. The Discovery of the Romero VMS Deposit and Its Bearing on the Metallogenic Evolution of Hispaniola during the Cretaceous. Minerals 2018, 8, 507; doi:10.3390/min8110507.
Patrocinador
This research has been financially supported by the Spanish projects CGL2012-36263 and CGL2015-65824, the Dominican project 2014-1B4-132, the Catalan projects SGR 2014-1661 and 2007-707 and by Goldquest Mining Corp.Résumé
The recently discovered Romero deposit, located in the Tres Palmas district, Cordillera
Central of the Dominican Republic, has probable reserves of 840,000 oz gold, 980,000 oz silver and
136 Mlb copper. Mineralization is hosted by intermediate volcanic and volcaniclastic rocks of the
lower stratigraphic sequence of the Cretaceous Tireo formation. The andesitic host rocks yield a
U-Pb zircon concordia age of 116 ± 10 Ma. Au–Ag–Cu(–Zn) mineralization is divided into: (1) an
upper domain with stacked massive sulfide lenses and sulfide dissemination within a 20-m-thick
level of massive anhydrite-gypsum nodules, and (2) a lower domain with a high-grade stockwork
mineralization in the form of cm-scale veins with open space fillings of fibrous silica and chalcopyrite,
sphalerite, pyrite (+electrum ± Au–Ag tellurides). The γ34S values of sulfides from the upper
(-7.6 and +0.9‰) and lower (-2.4 and +5.6‰) domains are consistent with a heterogeneous sourcing
of S, probably combining inorganically and organically induced reduction of Albian-Aptian seawater
sulfate. Despite this, a magmatic source for sulfur cannot be discarded. The γ34S (+19.2 and +20.0‰)
and _18O (+12.5 and +14.2‰) values of anhydrite-gypsum nodules are also consistent with a seawater
sulfate source and suggest crystallization in equilibrium with aqueous sulfides at temperatures higher
than 250ºC. These data point to a classification of Romero as a volcanogenic massive sulfide (VMS)
deposit formed in an axial position of the Greater Antilles paleo-arc in connection with island arc
tholeiitic magmatism during a steady-state subduction regime. Circulation of hydrothermal fluids
could have been promoted by a local extensional tectonic regime expressed in the Tres Palmas district
as a graben structure.