The Discovery of the Romero VMS Deposit and Its Bearing on the Metallogenic Evolution of Hispaniola during the Cretaceous

Minerals

JoaquínA. Proenza¹  MaríaClara Román-Alday¹  Lisard Torró²  Norverto González³  Alberto Amarante³  Jorge Espinoza³  Julio Espaillat³  ManuelJesús Román-Alpiste⁴  CarlE. Nelson⁵  AlbertJoan Belén-Manzeta⁶ 

[1] Departament de Mineralogia, Petrologia i Geologia Aplicada, Universitat de Barcelona (UB), Martí i Franquès s/n, 08028 Barcelona, Spain;Especialidad en Ingeniería Geológica, Facultad de Ciencias e Ingeniería, Pontificia Universidad Católica del Perú (PUCP), Av. Universitaria 180, San Miguel, Lima 15088, Peru;GoldQuest Mining Corp., 155 Wellington St. W Suite 2920, Toronto, ON M5V 3H1 Canada;Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, Av. de las Palmeras, 4, Armilla, 18100 Granada, Spain;Recursos del Caribe, S.A., 2360 23rd Street, Boulder, CO 80304, USA;Universidad Tecnológica del Cibao Oriental (UTECO), Av. Universitaria s/n, Cotuí, Sánchez Ramírez 43000, Dominican Republic;

关键词: VMS;    Caribbean Greater Antilles;    intra-oceanic island-arc;    metallogenic evolution;    Dominican Republic;   

DOI  :  10.3390/min8110507

来源: DOAJ

【 摘 要 】

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 δ³⁴S 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 δ³⁴S (+19.2 and +20.0‰) and δ¹⁸O (+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 250 °C. 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.

【 授权许可】

Unknown