Category Archives: 2012-1997

Geochemical and Sr-Nd isotope signatures of pristine slab melts and their residues (Sierra del Convento mélange, eastern Cuba) Abstract Major and trace element geochemical signatures and Sr–Nd isotope data of MORB-like amphibolite blocks and associated leucocratic low-K trondhjemitic rocks from the Sierra del Convento mélange (Cuba) indicate that oceanic crust underwent partial melting processes during…

Partial melting and counterclockwise P-T path of subducted oceanic crust (Sierra del Convento, E Cuba) Abstract Partial melting of subducted oceanic crust has been identified in the Sierra del Convento mélange (Cuba). This serpentinite-matrix mélange contains blocks of mid-ocean ridge basalt (MORB)-derived plagioclase-lacking epidote ± garnet amphibolite intimately associated with peraluminous trondhjemitic–tonalitic rocks. Field relations,…

Magmatic paragonite in trondhjemites from the Sierra del Convento mélange, Cuba Abstract In the Sierra del Convento mélange peraluminous trondhjemitic-tonalitic rocks, formed by partial melting of subducted oceanic crust at ca. 15 kbar, 700 °C, contain millimeter-sized crystals of paragonite that appear to be of magmatic origin. These crystals are replaced by plagioclase and quartz…

Chromite composition and platinum-group mineral assemblage of PGE-rich Loma Peguera chromitites, Loma Caribe peridotite, Dominican Republic Abstract The Loma Peguera chromitites are located in the central part of Loma Caribe peridotite in the Cordillera Central of Dominican Republic. The chromitite bodies are hosted in typical mantle peridotites, have small size (less than a few meters…

Geochemistry of cretaceous magmatism in Eastern Cuba: recycling of North American continental sediments and implications for subductions polarity in the Greater Antilles paleo-arc Abstract We present whole-rock major- and trace-element and Nd-Sr-Pb radiogenic isotope data for Cretaceous igneous suites from eastern Cuba. These rocks are related to the Greater Antilles paleo-island arc magmatism and have…

Os isotope heterogeneity of the upper mantle: Evidence from the Mayarí-Baracoa ophiolite belt in eastern Cuba Abstract In an attempt to quantify the extent of geochemical heterogeneity within a restricted and well dated portion of the upper mantle, 27 chromite separates from the 90 My old chromite deposits in the Mayar-Baracoa ophiolite belt in eastern…

Petrogenesis of highly depleted peridotites and gabbroic rocks from the Mayarí-Baracoa Ophiolitic Belt Abstract The Moa-Baracoa and Mayarí-Cristal massifs (eastern Cuba) are two ophiolitic complexes mainly constituted by harzburgite tectonites and minor dunites, cut by gabbroic dykes. The Moa-Baracoa massif exhibits a well developed Moho transition zone and an incomplete crustal section made up of…

Platinum group minerals in ophiolitic chromitites from Tehuitzingo (Acatlán complex, southern Mexico): implications for post-magmatic modification Abstract Podiform chromitite bodies occur in serpentinites at Tehuitzingo (Acatlán complex, southern Mexico). Serpentinite and chromitite are believed to represent a fragment of Paleozoic ophiolitic mantle formed in a supra-subduction zone setting. The ophiolitic mantle sequence is associated with…

High pressure metamorphism of ophiolites in Cuba Abstract High-pressure metamorphic complexes of ophiolitic material in Cuba trace the evolution of the northern margin of the Caribbean Plate during the Mesozoic. In the northern ophiolite belt of western and central Cuba, these complexes document cold (i.e., mature) subduction of oceanic lithosphere. Age data indicate subduction during…

Distribution of platinum-Group elements and Os isotopes in chromite ores from Mayarí-Baracoa Ophiolitic Belt (eastern Cuba) Abstract The Mayarí-Baracoa ophiolitic belt in eastern Cuba hosts abundant chromite deposits of historical economic importance. Among these deposits, the chemistry of chromite ore is very variable, ranging from high Al (Cr#=0.43-0.55) to high Cr (Cr#=0.60-0.83) compositions. Platinum-group element…

Paleozoic serpentine-enclosed chromitites from Tehuitzingo (Acatlán Complex, SW Mexico): a petrological and mineralogical study Abstract The serpentinites and associated chromitite bodies in Tehuitzingo (Acatlán Complex, southern Mexico) are in close relationship with eclogitic rocks enclosed within a metasedimentary sequence, suggesting that the serpentinites, chromitites and eclogitic rocks underwent a common metamorphic history. Primary chromites from…

D, O and C isotopes in podiform chromitites as fluid tracers for hidrotermal alteration processes of the Mayarí-Baracoa Ophiolitic Belt Abstract The Mayarí — Baracoa Ophiolitic Belt (MBOB, eastern Cuba) is composed of two large, chromite-rich massifs: Mayarí —Cristaland Moa-Baracoa. The chromitites and hosting dunites were firstly affected by a regional serpentinization event, a subsequent…

Source of ore-forming fluids in El Cobre VHMS deposit (Cuba): evidence from fluid inclusions and sulfur isotopes Abstract The El Cobre deposit, east of Cuba, lies in the intermediate volcanosedimentary sequence of the Sierra Maestra intraoceanic island arc. The structure of the deposit corresponds to that of a volcanogenic-hosted massive sulfide (VHMS) model. It comprises…

To Cite this article: Proenza, J.A., Melgarejo, J.C., Gervilla, F.(2003): Comments on the paper “Ocherous laterite: a nickel ore from Punta Gorda, Cuba” by Oliveira et al. Journal of South American Earth Sciences, 16, 199-202.

Metabasites from the northern serpentinite belt (Cuba) and a metamorphic perspective of the plate tectonic models for the Caribbean region Abstract The analysis of metamorphosed magmatic rocks along the northern serpentinite belt (Cuba) suggest a variety of tectonic settings of formation and metamorphism. Slightly deformed coherent bodies of metabasites from Cajálbana (western Cuba) and Iguará-Perea…

Oscillatory zoning in eclogitic garnet and amphibole, Northern Serpentinite Melange, Cuba: a record of tectonic instability during subduction? Abstract Exotic blocks of eclogite from distant localities along the Northern Serpentinite Melange of Cuba have comparable P–T histories that include high-pressure prograde sections (450–600 °C, >15 kbar) associated with subduction of oceanic lithosphere, and retrograde sections within the albite–epidote…

High-grade metamorphism and hydrous melting of metapelites in the Pinos terrane (W Cuba): Evidence for crustal thickening and extension in the northern Caribbean collisional belt Abstract The Pinos terrane (Isle of Pines, W Cuba) is a coherent metamorphic complex that probably represents a portion of the continental margin of the Yucatan Block during the Mesozoic.…

Genesis of sulfide-rich chromite ores by the interaction between chromitite and pegmatitic olivine-norite dikes in the Potosí Mine (Moa-Baracoa ophiolitic massif, eastern Cuba) Abstract The Potosí Mine is located in the Moa-Baracoa massif in the easternmost part of the Cuban Ophiolitic Belt. Chromite mineralization occurs within the mantle–crust transition zone. Two events of magma intrusion…

Uvarovite in podiform chromitites: the Moa-Baracoa ophiolitic massif, Cuba Abstract The chromitite pods of the Moa-Baracoa massif, in the eastern ophiolitic belt of Cuba, contain pre-existing gabbro sills. This association is affected by two processes of hydrothermal alteration. The chromitites and the hosting dunites and harzburgites are affected first by regional serpentinization; a second alteration,…