Category Archives: 2012-1997

Hydrothermal origin and age of jadeitites from Sierra del Convento Mélange (Eastern Cuba) Abstract Jadeitite (jadeite jade) from Sierra del Convento (eastern Cuba) occurs in a subduction-related serpentinite-matrix mélange associated with a variety of high-pressure tectonic blocks including garnet-amphibolites and related anatectic trondhjemites. The eastern Cuban jadeitite is massive and characterized by rare quartz inclusions…

To Cite this article: Ruiz-Jímenez, E. C., Blanco-Quintero, I.F., Toro Toro, L.M., Moreno-Sánchez, M., Vinasco, C.J., García-Casco, A., Morata, D., Gómez-Cruz, A. (2012): Geochemistry and petrology of metabasites of the Arquia Complex (Santa Fe de Antioquia and Arquia Creek, Colombia): Geodynamic implications. Boletín de Ciencias de la Tierra, 32, 65-8O. ISSN 012-3630.  http://intranet.minas.medellin.unal.edu.co/index.php?option=com_docman&task=doc_download&gid=2291&Itemid=57

Petrogenesis of fertile mantle peridotites from the Monte del Estado massif (southwest Puerto Rico): a preserved section of proto-caribbean lithospheric mantle? Abstract The Monte del Estado massif is the largest and northernmost serpentinized peridotite belt in southwest Puerto Rico. It is mainly composed of spinel lherzolite and minor harzburgite with variable clinopyroxene modal abundances. Mineral…

Timing and Evolution of Cretaceous Island Arc Magmatism in Central Cuba: Implications for the History of Arc Systems in the Northwestern Caribbean Abstract SHRIMP and conventional zircon dating place temporal constraints on the evolution of the Cretaceous Volcanic Arc system in central Cuba. The arc has a consistent stratigraphy across strike, with the oldest and…

Subduction of young oceanic plates: a numerical study with application to aborted thermal-chemical plumes Abstract We investigated numerical models of initiation and subsequent evolution of subduction of young (10–30 Myr) oceanic lithosphere. Systematic numerical experiments were carried out by varying the age of the subducting plate (10, 12.5, 15, 17.5, 20, 25 and 30 Myr),…

Timing of subduction and exhumation in a subduction channel: Evidence from slab melts from La Corea mélange (eastern Cuba) Abstract High pressure igneous rocks (tonalites), generated by partial melting of subducted basaltic rocks accreted to the mantle wedge, are present in the La Corea serpentinite-matrix mélange (eastern Cuba) as centimeter- to meter-sized blocks and as…

Serpentinites and serpentinites within a fossil subdution channel: La Corea melange, eastern Cuba. Abstract A variety of metaultramafic (serpentinite) rocks in La Corea mélange, Sierra de Cristal, eastern Cuba, show differences in chemical, textural and mineralogical characteristics demonstrating a variety of protoliths. The mélange originated during the Cretaceous as part of the subduction channel associated…

Subduction Zones of the Caribbean: the sedimentary, magmatic, metamorphic and ore-deposit records. UNESCO/IUGS-IGCP Project 546 Subduction Zones of the Caribbean Abstract This special issue of Geologica Acta, containing fourteen papers, is representative of the aims of IGCP 546, for it covers most of the cutting-edge topics pertaining to the Caribbean’s geological development from the Jurassic…

The imprint of subducion fluids on subducted MORB-derived melts (Sierra del Convento mélange, Cuba) Abstract Major and trace element signatures and Sr–Nd–Pb isotope data for muscovite (Ms)-bearing amphibolite blocks and associated muscovite-bearing trondhjemite and quartz-muscovite rocks from the Sierra del Convento mélange (eastern Cuba) indicate that Proto-Caribbean oceanic crust underwent wet partial melting processes during…

Barium-rich fluids and melts in the subduction environment (La Corea and Sierra del Convento mélanges, eastern Cuba) Abstract Whole-rock compositions of muscovite-bearing amphibolite, trondhjemite, pegmatite and quartz-muscovite rocks from Sierra del Convento and La Corea mélanges (eastern Cuba), as well as mineralogy, record complex circulation of Ba-rich fluids and melts in the subduction environment. Partial…

Tectonic blocks in serpentinite melange (eastern Cuba) reveal large-scale convective flow of the subduction channel Abstract Detailed petrological study of mid-oceanic ridge basalt−derived high-pressure amphibolite blocks from a fragment of the Caribbean subduction channel (La Corea serpentinite-matrix mélange, eastern Cuba) has revealed contrasted zoning patterns of garnet porphyroblasts, including well-defined complex oscillatory prograde-retrograde concentric zoning…

Las cromititas del Complejo Ofiolítico de Camagüey, Cuba: un ejemplo de cromitas ricas en Al Abstract El Complejo Ofiolítico de Camagüey se sitúa en la región centro-oriental de la Isla de Cuba. Este complejo ofiolítico contiene importantes depósitos de cromita rica en Al [Cr/(Cr+Al) = 0.31-0.6] y TiO2 (hasta 1% en peso), y representa el…

Garutiite, (Ni,Fe,Ir) a new hexagonal polymorph of native Ni from Loma Peguera, Dominican Republic Abstract Garutiite (Ni,Fe,Ir) is a new hexagonal polymorph of native Ni discovered in chromitite from Loma Peguera, Dominican Republic. The mineral was identified in heavy mineral concentrates obtained through the use of electric pulse disaggregation (EPD) and hydroseparation (HS) techniques. It…

Sorption of Ni by "lithiophorite-asbolane" intermediates in Moa Bay lateritic deposits, eastern Cuba Abstract The Moa Bay Ni-Co laterite deposits, placed in the so-called Mayari-Baracoa ophiolitic belt (eastern Cuba), are oxide type. Despite its geological relevance and economical impact no detailed studies exist with regards to cristallochemical characterization of Ni incorporated in (or attached to)…

In situ Re–Os isotopic analysis of platinum-group minerals from the Mayarí-Cristal ophiolitic massif (Mayarí-Baracoa Ophiolitic Belt, eastern Cuba): implications for the origin of Os-isotope heterogeneities in podiform chromitites Abstract Chromitite pods in the Mayarí-Cristal ophiolitic massif (eastern Cuba) were formed in the Late Cretaceous when island arc tholeiites and MORB-like back-arc basin basalts reacted with…

Chromite and platinum-group-elements mineralization in the Santa Elena ophiolitic ultramafic nappe (Costa Rica): geodynamic implications Abstract Chromitites associated with strongly altered peridotite from six distinct localities in the Santa Elena ultramafic nappe (Costa Rica) have been investigated for the first time. Santa Elena chromitites commonly display a compositional variation from extremely chromiferous (Cr/(Cr+Al)=0.81) to intermediate…

The metallogenic evolution of the Greater Antilles Abstract The Greater Antilles host some of the world’s most important deposits of bauxite and lateritic nickel as well as significant resources of gold and silver, copper, zinc, manganese, cobalt and chromium. Beginning in Jurassic time, sedimentary exhalative base metal deposits accumulated in marine sedimentary rift basins as…

Sorption of Ni by "lithiophorite-asbolane" intermediates in Moa Bay lateritic deposits, eastern Cuba Abstract The Moa Bay Ni–Co laterite deposits, placed in the so-called Mayari–Baracoa ophiolitic belt (eastern Cuba), are oxide type. Despite its geological relevance and economical impact no detailed studies exist with regards to cristallochemical characterization of Ni incorporated in (or attached to)…

Zircon ages, Sr-Nd-Hf isotopic compositions, and geochemistry of granitoids associated with the northern ophiolite mélange of central Cuba: Tectonic implication for late Cretaceous magmatism in the northwestern Caribbean Abstract The geology of Cuba is representative of the orogenic belt fringing the northwesternmost margin of the Caribbean plate. It is characterized by a tectonic collage made…

Metamorphic evolution of subducted hot oceanic crust (La Corea mélange, Cuba) Abstract Thermobarometric estimates and predictions of theoretical and experimental isochemical P-T phase diagrams for epidote±garnet amphibolite blocks from the serpentinite mélange of La Corea (eastern Cuba) indicate partial melting of subducted oceanic lithosphere occurred at peak metamorphic conditions of ca. 700 °C and 14…