9 research outputs found
Volatile (Cl, F and S) and major element constraints on subduction-related mantle metasomatism along the alkaline basaltic backarc, Payenia, Argentina
No full textEnrichments of the mantle sources beneath the Southern Volcanic Zone (Andes) by fluids and melts derived from abraded upper continental crust
No full textSatellite Regional Magnetic Anomalies as a Reflection of the Geological and Geophysical Properties of the Lithosphere (According to Champ Data)
No full textTransient mantle cooling linked to regional volcanic shut-down and early rifting in the North Atlantic Igneous Province
No full textThe Miocene Magmatism in the Malargüe and Chos Malal Fold and Thrust Belts
No full textLate Oligocene to Pliocene magmatism at the latitudes of Malargüe and Chos Malal fold and thrust belts, in Neuquén basin, is distributed from the main Andean axis to the retroarc zone. While arc magmatism maintained relatively similar compositional and geochemical features during late Oligocene to Pliocene times, major variations are seen in volcanic sequences developed in the retroarc zone, due to the development of the shallow subduction regime by mid-late Miocene times. Thus, late Oligocene-early Miocene period is characterized by an extensional regime that conditioned mainly tholeiitic magmas in the main Andean axis and alkaline, intraplate magmas in the retroarc zone. Early-late Miocene marks a change to more compressional tectonics in the Andean margin. Main arc magmatism showed a change to clearer arc, calc-alkaline signature, while retroarc magmatism showed the progressing input of slab-derived products as the shallow subduction regime triggered the eastward migration of the asthenospheric wedge. Thus, arc-derived lavas expanded into the mid to far retroarc zone (~69°30? to 68°30?) with arc-like andesitic to dacitic compositions.With the progressive influence of the shallow subduction regime, arc-derived products reached almost 500 km away from the Chilean trench at ∽36°S by latest Miocene-Pliocene. By middle Pliocene, re-steepening of the slab conditioned extensional tectonics that favored a widespread alkaline volcanism in the present-day Payenia retroarc and rhyolitic calderas main arc zone. After ∽3.5 Ma, retroarc magmatism at the latitudes of the Malargüe and Chos Malal fold and thrust belts lack of clear arc-related geochemical features.Fil: Litvak, Vanesa Dafne. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; ArgentinaFil: Iannelli, Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; ArgentinaFil: Fernández Paz, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; ArgentinaFil: Folguera Telichevsky, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; Argentin
Copper partitioning between olivine and melt inclusions and its content in primitive island-arc magmas of Kamchatka
No full textPlume Subduction Beneath the Neuquén Basin and the Last Mountain Building Stage of the Southern Central Andes
No full textThe occurrence of a Neogene shallow subduction stage, as well as, a Pliocene slab-tearing, and steepening of the Nazca plate in the southern Central Andes are well established. However, a satisfactory explanation for the origin and connection between these complex processes is still elusive. In this contribution, we revise the late Cenozoic tectonic and magmatic evolution of the southern Central Andes between 35° and 38° S and discuss different proposals for the Miocene slab shallowing and its Pliocene destabilization. Recent plate kinematic reconstructions show that Neogene arc-front expansion linked to slab shallowing, fold belt reactivation in the main cordillera and intraplate contraction in the San Rafael Block correlates with the subduction of the ancient Payenia plume, a deep mantle anomaly potentially rooted in the lower mantle. Also, the Nazca slab tear determined from tomographic analyses and subsequent slab steepening may also be a direct consequence of this plume subduction process. Considering the westward drift of South America and the presence of several neighbor hotspots over the Nazca plate, the Payenia plume overriding could be the first of future episodes of plume?trench interaction in the Andes.Fil: Gianni, Guido Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: Pesce, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: García, Luciano Héctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: Lupari, Marianela Nadia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: Correa Otto, Sebastian Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: Nacif Suvire, Silvina Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: Folguera Telichevsky, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentin
