Geochemical constraints on blueschist- and amphibolite-facies rocks of the Central Cordillera of Colombia: the Andean Barragán region

Subduction zones are one of the most characteristic features of planet Earth. Convergent plate junctions exert enormous influence on the formation and recycling of continental crust, and they are also responsible for major mineral resources and earthquakes, which are of crucial importance for society. A subduction-related geologic unit containing high-pressure rocks occurs in the Barragán area (Valle del Cauca Department) on the western flank of the Central Cordillera of the Colombian Andes. Blueschists and amphibolites, serpentinized meta-ultramafic rocks, graphite-chlorite-muscovite-quartz schists, protocataclasites, and graphite-chlorite-andalusite-andesine-garnet-muscovite ±  titanite schists are exposed in this region. In spite of the petrotectonic importance of blueschists, the high-pressure metamorphism of the Central Cordillera of Colombia has been rarely studied. New geochemical data indicate that protoliths of the blueschist- and amphibolite-facies rocks possessed normal mid-ocean ridge basalt bulk compositions. 40Ar/39Ar geochronology for a metapelite rock associated with the blueschists shows a plateau age of ∼120 million years. We suggest that high-P/T conditions were present from ∼150 to 125 Ma, depending on the model of generation and exhumation considered.

[1]  H. A. Lallemant.  Displacement Partitioning and Arc‐Parallel Extension: Example from the Southeastern Caribbean Plate Margin , 2013 .

[2]  C. Juliani,et al.  40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia: implications on the styles of accretion in the Northern Andes , 2011 .

[3]  T. Harrison,et al.  Diffusion of 40Ar in muscovite , 2009 .

[4]  T. Harrison,et al.  Diffusion of 40 Ar in muscovite , 2009 .

[5]  J. Pindell,et al.  Tectonic evolution of the Gulf of Mexico, Caribbean and northern South America in the mantle reference frame: an update , 2009 .

[6]  Andrés Bustamante Londoño.  Geotermobarometria, geoquímica, geocronologia e evolução tectônica das rochas da fácies xisto azul da Colômbia nas áreas de Jambaló (Cauca) e Barragán (Valle del Cauca) , 2008 .

[7]  J. Pearce.  Geochemical fingerprinting of oceanic basalts with applications to ophiolite classification and the search for Archean oceanic crust , 2008 .

[8]  M. Cosca,et al.  Isotopic constraints on the thermal history of the Wind River Range, Wyoming: implications for Archean metamorphism , 2006 .

[9]  U. Cordani,et al.  Geochronological, isotopic, and geochemical data from Permo-Triassic granitic gneisses and granitoids of the Colombian Central Andes , 2006 .

[10]  A. Kerr,et al.  The Quebradagrande Complex: A Lower Cretaceous ensialic marginal basin in the Central Cordillera of the Colombian Andes , 2006 .

[11]  E. Ghent,et al.  Coherent French Range blueschist: Subduction to exhumation in <2.5 m.y.? , 2004 .

[12]  K. Schulmann,et al.  Evolutionary Model for Exhumation of the Meliata Blueschists, Western Carpathians (Slovakia) , 2004 .

[13]  A. Kerr,et al.  The nature and provenance of accreted oceanic terranes in western Ecuador: geochemical and tectonic constraints , 2002, Journal of the Geological Society.

[14]  L. Beccaluva,et al.  The southern margin of the Caribbean Plate in Venezuela: tectono-magmatic setting of the ophiolitic units and kinematic evolution , 2002 .

[15]  H. Lapierre,et al.  Geodynamic significance of the Raspas Metamorphic Complex (SW Ecuador): geochemical and isotopic constraints , 2002 .

[16]  R. W. Le Maitre,et al.  Igneous Rocks: A Classification and Glossary of Terms , 2002 .

[17]  B. Pluijm,et al.  Late Proterozoic (ca. 930 Ma) extension in eastern Laurentia , 2000 .

[18]  V. Ramos.  Plate tectonic setting of the Andean Cordillera , 1999 .

[19]  A. Kerr,et al.  Cretaceous Basaltic Terranes in Western Colombia: Elemental, Chronological and Sr-Nd Isotopic Constraints on Petrogenesis , 1997 .

[20]  H. G. Iregui.  Metagabros y Eclogitas Asociadas en el Area de Barragán, Departamento del Valle, Colombia , 1997 .

[21]  H. González,et al.  Unidades litodémicas en la cordillera Central de Colombia , 1995, Boletín Geológico.

[22]  G. Draper,et al.  Metamorphic belts in central Hispaniola , 1991 .

[23]  B. Cabanis.  Le diagramme La/10-Y/15-Nb/8 : unoutil pour la discrimination des series volcaniques et la mise en evidence des processus de melande et/ou de contamination crustale , 1989 .

[24]  R. W. Le Maitre,et al.  A Classification of igneous rocks and glossary of terms : recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks , 1989 .

[25]  J. Toussaint,et al.  Terranes and Continental Accretion in the Colombian Andes , 1988 .

[26]  J. Bourgois,et al.  Geological history of the Cretaceous ophiolitic complexes of northwestern South America (Colombian Andes) , 1987 .

[27]  M. Meschede.  A method of discriminating between different types of mid-ocean ridge basalts and continental tholeiites with the Nb1bZr1bY diagram , 1986 .

[28]  J. Aspden,et al.  Mesozoic oceanic terrane in the Central Andes of Colombia , 1986 .

[29]  John W. Shervais,et al.  Ti-V plots and the petrogenesis of modern and ophiolitic lavas , 1982 .

[30]  Julian A. Pearce,et al.  Trace element characteristics of lavas from destructive plate boundaries , 1982 .

[31]  David A. Wood,et al.  The application of a ThHfTa diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary Volcanic Province , 1980 .

[32]  T. Feininger.  Eclogite and Related High-Pressure Regional Metamorphic Rocks from the Andes of Ecuador , 1980 .

[33]  J. Pearce,et al.  Petrogenetic implications of Ti, Zr, Y, and Nb variations in volcanic rocks , 1979 .

[34]  J. Winchester,et al.  Geochemical discrimination of different magma series and their differentiation products using immobile elements , 1977 .

[35]  A. Miyashiro,et al.  Tholeiitic and calc-alkalic series in relation to the behaviors of titanium, vanadium, chromium, and nickel , 1975 .

[36]  T. Irvine,et al.  A Guide to the Chemical Classification of the Common Volcanic Rocks , 1971 .