Late Cretaceous radiolarian biochronology of the Pedro Brand section, Tireo Group, eastern Central Cordillera, Dominican Republic: A contribution to the stratigraphy of the Caribbean Large Igneous Province

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

“…Geologically, it is a complex composite of crustal and mantle units that formed within an intra-oceanic environment since the Late Jurassic time and that accreted in the aftermath of the collision between the Caribbean island-arc and the Bahamas Platform in the Eocene time [21][22][23]. Rock units cropping out along the Central Cordillera are representative of (1) ultramafic, mostly serpentinized peridotites of probable Late Jurassic or Early Cretaceous protolith (including the so-called Loma Caribe peridotites [15,24,25]), (2) MORB-type volcano-plutonic assemblages representative of the Proto-Caribbean oceanic lithosphere (Loma la Monja assemblage [26]), (3) basaltic volcanic rocks of the Caribbean Large Igneous Province (CLIP, which comprises the plume-related Caribbean-Colombian Oceanic Plateau-CCOP), of the Jurassic to the latest Cretaceous age (Duarte complex and Pelona-Pico Duarte, Peña Blanca and Siete Cabezas formations [23,[27][28][29][30][31][32]), and (4) igneous and sedimentary rocks associated with island arc(s) of Cretaceous age [33] (the corresponding units are described below). These basement rocks were variably deformed and metamorphosed [28,[34][35][36][37][38], and are unconformably overlain by late Eocene to Holocene sedimentary rocks, which include siliciclastic and carbonate deposits.…”

“…Limestone lenses within the upper part of the upper volcanic sequence were dated at lower Senonian (i.e., broadly Coniacian-Santonian) in the Las Canitas area, and at early Maastrichtian to the east of Constanza [53]. In addition, radiolarians from a tuffaceous chert in the Pedro Brand section, northwest of Santo Domingo, indicate a Turonian-Coniacian age [32]. The coeval deposition of deep and shallow water pyroclastic rocks, the regional tectonics and the stratigraphic relationships with correlated units outside the main "Tireo basin" led Lewis et al [53] to propose rapid changes in the depth of the main basin in the framework of caldera collapse associated with a graben structure.…”