Volcanoes: Ice and Fire

Total Page:16

File Type:pdf, Size:1020Kb

Volcanoes: Ice and Fire Journeys@Home Volcanoes: Ice and Fire Parinacota Looking Due North across Lago Chungara—5 Days at 15,400’, 2015 Tony Foster went to Chile on the advice of renowned volcanologist, Sir Stephen Sparks, to paint a beautiful volcano for his Exploring Beauty Journey. Tony told Sir Sparks that he had painted this particular volcano before. To that Sir Sparks replied, “not from the Chilean side.” Tony could not argue. He painted Parinacota from its Bolivian side in 1997 for his Ice and Fire Journey. Volcanoes are known to be subjects of destruction and creation. When one thinks of a volcano, one may recall lava, magma, and eruptions. These giants of the earth loom large above their landscapes. Some are so high that they are Cerro Parinacota SW from a Ridge below Cerro Pomerape, 1997 covered with snow all year round! The Foster | 940 Commercial St., Palo Alto, CA 94303 | www.thefoster.org Activity: Citrus Volcanoes Try your very own citrus volcano. We used a lemon, but you can try different citrus fruits to see the reactions they can make. How do you think limes, oranges, grapefruits, or tangerines would react? The Tools You’ll Need: ◆ Citrus Fruit ◆ Dish to Contain the Citrus Volcano ◆ Baking Soda ◆ Food Coloring ◆ Extra Citrus Fruit Juice ◆ Spoon ◆ Small Cup for Baking Soda (We used a recycled apple sauce cup!) STEP 1: Cut off the base STEP 2: Put the fruit in STEP 3: Drop the food STEP 4: Pour a generous of your fruit to make a flat the dish. Use a craft stick coloring onto the citrus amount of baking soda on spot on the bottom. Then to poke holes in your fruit. fruit. Add extra citrus fruit top of the fruit and poke cut your fruit in half. juice to the fruit. with a craft stick. A Few Volcano Facts There are three types of volcanic classifications:active , dormant, and extinct. These classifications refer to the activity of the volcano. Active—An active volcano has regular activity. These activities may include signs of smoke, eruptions, and earthquakes. Dormant—A dormant volcano has erupted in recent history, but remains quiet now. Extinct—An extinct volcano has not had an eruption for a very long time, so long that it is unlikely to ever erupt again. The Foster | 940 Commercial St., Palo Alto, CA 94303 | www.thefoster.org Two Main Types of Volcanoes SHIELD VOLCANO A cone-shaped volcano with steep slopes is called a shield volcano. Parinacota in Chile is an example of a shield volcano. Tony Foster painted Parinacota as part of two Journeys: Exploring Beauty and Ice and Fire. Parinacota volcano at Parque Nacional Lauca, Chile. October 2015. Photo by Mattias Lanas. COMPOSITE VOLCANO A wide-shaped volcano with gentle slopes is called a composite volcano. Kilauea in Hawaii is an example of a composite volcano. Tony Foster painted Kilauea as part of his Ice and Fire Journey. The rim of Kilauea, Hawaii, taken from the Volcano Observatory helicopter, October 2, 1997. Activity: Lava Slime Gather a few ingredients to make your own lava slime! The Tools You’ll Need: ◆ Elmers Glue ◆ Water ◆ Liquid Starch ◆ Food Coloring ◆ Bowl ◆ Spoon ◆ Small Cup for Measuring (We used a recycled apple sauce cup!) Step 1: Pour a cup of Step 2: Add a cup of Step 3: Knead the slime Step 4: Enjoy playing with your glue, a cup of water, and liquid starch and quickly with your hands. It will lava slime! some food coloring into a mix. The slime will start be sticky at first, but will bowl. Mix thoroughly. to thicken. Keep stirring come together. until it comes together. The Foster | 940 Commercial St., Palo Alto, CA 94303 | www.thefoster.org August 2020.
Recommended publications
  • Appendix A. Supplementary Material to the Manuscript
    Appendix A. Supplementary material to the manuscript: The role of crustal and eruptive processes versus source variations in controlling the oxidation state of iron in Central Andean magmas 1. Continental crust beneath the CVZ Country Rock The basement beneath the sampled portion of the CVZ belongs to the Paleozoic Arequipa- Antofalla terrain – a high temperature metamorphic terrain with abundant granitoid intrusions that formed in response to Paleozoic subduction (Lucassen et al., 2000; Ramos et al., 1986). In Northern Chile and Northwestern Argentina this Paleozoic metamorphic-magmatic basement is largely homogeneous and felsic in composition, consistent with the thick, weak, and felsic properties of the crust beneath the CVZ (Beck et al., 1996; Fig. A.1). Neodymium model ages of exposed Paleozoic metamorphic-magmatic basement and sediments suggest a uniform Proterozoic protolith, itself derived from intrusions and sedimentary rock (Lucassen et al., 2001). AFC Model Parameters Pervasive assimilation of continental crust in the Central Andean ignimbrite magmas is well established (Hildreth and Moorbath, 1988; Klerkx et al., 1977; Fig. A.1) and has been verified by detailed analysis of radiogenic isotopes (e.g. 87Sr/86Sr and 143Nd/144Nd) on specific systems within the CVZ (Kay et al., 2011; Lindsay et al., 2001; Schmitt et al., 2001; Soler et al., 2007). Isotopic results indicate that the CVZ magmas are the result of mixing between a crustal endmember, mainly gneisses and plutonics that have a characteristic crustal signature of high 87Sr/86Sr and low 145Nd/144Nd, and the asthenospheric mantle (low 87Sr/86Sr and high 145Nd/144Nd; Fig. 2). In Figure 2, we model the amount of crustal assimilation required to produce the CVZ magmas that are targeted in this study.
    [Show full text]
  • Volcán Lascar
    Volcán Lascar Región: Antofagasta Provincia: El Loa Comuna: San Pedro de Atacama Coordenadas: 21°22’S – 67°44’O Poblados más cercanos: Talabre – Camar – Socaire Tipo: Estratovolcán Altura: 5.592 m s.n.m. Diámetro basal: 8.9 km Área basal: 62.2 km2 Volumen estimado: 28.5 km3 Última actividad: 2015 Última erupción mayor: 1993 Volcán Lascar. Vista desde el norte Ranking de riesgo (Fotografía: Gabriela Jara, SERNAGEOMIN) 14 específico: Generalidades El volcán Láscar corresponde a un estratovolcán compuesto, elongado en dirección este-oeste, activo desde hace unos 240 ka y emplazado en el margen oeste de la planicie altiplánica. Está conformado por lavas andesíticas, que alcanzan más de 10 km de longitud, y por potentes lavas dacíticas que se extienden hasta 5 km, las que fueron emitidas desde los flancos NO a SO. La lava más reciente se estima en 7 mil años de antigüedad. En los alrededores del volcán se reconocen depósitos de flujo y caída piroclástica, además de numerosos cráteres de impacto asociados a la eyección de bombas durante erupciones plinianas y subplinianas. El principal evento eruptivo durante su evolución se denomina Ignimbrita Soncor, generado hace unos 27 ka al oeste del volcán y con un volumen estimado cercano a los 10 km3. En la cima de este volcán se observan seis cráteres, algunos anidados, y el central de estos se encuentra activo. Registro eruptivo Este volcán ha presentado alrededor de 30 erupciones explosivas desde el siglo XIX, lo que lo convierte en el volcán más activo del norte de Chile. Estos eventos han consistido típicamente en erupciones vulcanianas de corta duración, con emisión de ceniza fina y proyecciones balísticas en un radio de 5 km, donde el último evento de este tipo ocurrió el 30 de octubre del 2015.
    [Show full text]
  • Actualización Plan Director De Infraestructura Mop
    REPÚBLICA DE CHILE MINISTERIO DE OBRAS PÚBLICAS DIRECCIÓN DE PLANEAMIENTO ACTUALIZACIÓN PLAN DIRECTOR DE INFRAESTRUCTURA MOP Informe Final Región de Antofagasta Chile, Noviembre de 2009 INECON, Ingenieros y Economistas Consultores S.A. ÍNDICE 1. CARACTERÍSTICAS DE LA REGIÓN DE ANTOFAGASTA ............................ 1 1.1. Características generales. ............................................................................. 1 1.2. Características económicas. .......................................................................... 1 1.3. Características de la población. ..................................................................... 2 1.4. Gasto histórico en infraestructura por parte del MOP. ...................................... 2 2. IMAGEN OBJETIVO DE LA REGIÓN DE ANTOFAGASTA ............................ 3 2.1. Diagnósticos, objetivos estratégicos y visiones pertinentes. .............................. 3 2.1.1. Estrategia de Desarrollo Regional (EDR) ................................................... 3 2.1.2. Visión 2020- Talleres MOP ..................................................................... 4 2.1.3. Reconocimiento Territorial ...................................................................... 4 2.2. Oportunidades y restricciones de la región. ..................................................... 5 2.2.1. Oportunidades ...................................................................................... 5 2.2.2. Restricciones .......................................................................................
    [Show full text]
  • English / French
    World Heritage 38 COM WHC-14/38.COM/INF.8B4.Rev Doha, 16 June 2014 Original: English / French UNITED NATIONS EDUCATIONAL, SCIENTIFIC AND CULTURAL ORGANIZATION CONVENTION CONCERNING THE PROTECTION OF THE WORLD CULTURAL AND NATURAL HERITAGE WORLD HERITAGE COMMITTEE Thirty-eighth session Doha, Qatar 15 – 25 June 2014 Item 8 of the Provisional Agenda: Establishment of the World Heritage List and of the List of World Heritage in Danger INF.8B4: Factual error letters SUMMARY This document contains the factual errors notifications received from States Parties by 2 June 2014 in compliance with paragraph 150 of the Operational Guidelines. This document cancels and replaces the previous one. Alphabetical list by State Party of notifications of factual errors in the evaluation reports of the Advisory Bodies relating to nominations to be examined at the 38th session of the World Heritage Committee (15-25 June 2014) State Party World Heritage nomination ID No. Recommendation Pp Argentina, Bolivia, Qhapaq Ñan, Andean Road System 1459 I 2 Chile, Colombia, Ecuador, Peru Belgium Plantin-Moretus House-Workshops-Museum Complex 1185 Bis N 9 (MBM) Botswana Okavango Delta 1432 I 11 China / Kazakhstan / Silk Roads: Initial Section of the Silk Roads, the Routes 1442 I 14 Kyrgyzstan Network of Tian-shan Corridor China / Kazakhstan / Silk Roads: Initial Section of the Silk Roads, the Routes 1442 I 17 Kyrgyzstan Network of Tian-shan Corridor Denmark Stevns Klint 1416 I 19 France Tectono-volcanic Ensemble of the Chaine des Puys and 1434 N 20 Limagne Fault Germany
    [Show full text]
  • The Origin and Emplacement of Domo Tinto, Guallatiri Volcano, Northern Chile Andean Geology, Vol
    Andean Geology ISSN: 0718-7092 [email protected] Servicio Nacional de Geología y Minería Chile Watts, Robert B.; Clavero Ribes, Jorge; J. Sparks, R. Stephen The origin and emplacement of Domo Tinto, Guallatiri volcano, Northern Chile Andean Geology, vol. 41, núm. 3, septiembre, 2014, pp. 558-588 Servicio Nacional de Geología y Minería Santiago, Chile Available in: http://www.redalyc.org/articulo.oa?id=173932124004 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Andean Geology 41 (3): 558-588. September, 2014 Andean Geology doi: 10.5027/andgeoV41n3-a0410.5027/andgeoV40n2-a?? formerly Revista Geológica de Chile www.andeangeology.cl The origin and emplacement of Domo Tinto, Guallatiri volcano, Northern Chile Robert B. Watts1, Jorge Clavero Ribes2, R. Stephen J. Sparks3 1 Office of Disaster Management, Jimmit, Roseau, Commonwealth of Dominica. [email protected] 2 Escuela de Geología, Universidad Mayor, Manuel Montt 367, Providencia, Santiago, Chile. [email protected] 3 Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol. BS8 1RJ. United Kingdom. [email protected] ABSTRACT. Guallatiri Volcano (18°25’S, 69°05’W) is a large edifice located on the Chilean Altiplano near the Bo- livia/Chile border. This Pleistocene-Holocene construct, situated at the southern end of the Nevados de Quimsachata chain, is an andesitic/dacitic complex formed of early stage lava flows and later stage coulées and lava domes.
    [Show full text]
  • Convergent Margin Magmatism in the Central Andes and Its Near Antipodes in Western Indonesia: Spatiotemporal and Geochemical Considerations
    AN ABSTRACT OF THE DISSERTATION OF Morgan J. Salisbury for the degree of Doctor of Philosophy in Geology presented on June 3, 2011. Title: Convergent Margin Magmatism in the Central Andes and its Near Antipodes in Western Indonesia: Spatiotemporal and Geochemical Considerations Abstract approved: ________________________________________________________________________ Adam J.R. Kent This dissertation combines volcanological research of three convergent continental margins. Chapters 1 and 5 are general introductions and conclusions, respectively. Chapter 2 examines the spatiotemporal development of the Altiplano-Puna volcanic complex in the Lípez region of southwest Bolivia, a locus of a major Neogene ignimbrite flare- up, yet the least studied portion of the Altiplano-Puna volcanic complex of the Central Andes. New mapping and laser-fusion 40Ar/39Ar dating of sanidine and biotite from 56 locations, coupled with paleomagnetic data, refine the timing and volumes of ignimbrite emplacement in Bolivia and northern Chile to reveal that monotonous intermediate volcanism was prodigious and episodic throughout the complex. 40Ar/39Ar age determinations of 13 ignimbrites from northern Chile previously dated by the K-Ar method improve the overall temporal resolution of Altiplano-Puna volcanic complex development. Together with new and updated volume estimates, the new age determinations demonstrate a distinct onset of Altiplano-Puna volcanic complex ignimbrite volcanism with modest output rates beginning ~11 Ma, an episodic middle phase with the highest eruption rates between 8 and 3 Ma, followed by a general decline in volcanic output. The cyclic nature of individual caldera complexes and the spatiotemporal pattern of the volcanic field as a whole are consistent with both incremental construction of plutons as well as a composite Cordilleran batholith.
    [Show full text]
  • Role of Differentiation and Mixing Processes in the Evolution of Central Andean Magma Systems: an Experimental Approach
    Geophysical Research Abstracts, Vol. 11, EGU2009-10444, 2009 EGU General Assembly 2009 © Author(s) 2009 Role of differentiation and mixing processes in the evolution of Central Andean magma systems: An experimental approach R.E. Botcharnikov (1), C. Bonecke (1), F. Holtz (1), G. Torresi (1), M. Banaszak (2), and G. Wörner (2) (1) Institut für Mineralogie Universität Hannover, Callinstr. 3, 30167 Hannover, Germany ([email protected]), (2) Geowissenschaftliches Zentrum Göttingen, Abt. Geochemie, Goldschmidtstr.1, 37077 Göttingen, Germany The compositional evolution of magmatic systems is controlled by many factors, numerous processes and prevail- ing conditions at depths of magma generation, storage and ascent. The most important processes responsible for the chemical variations observed in most erupted magmas are magma differentiation during crystallization and magma mixing/hybridization. We present preliminary results of the crystallization experiments on the two magma compositions representative of the least evolved basaltic andesite magmas from Parinacota volcano and of the dacitic magmas from Taapaca volcano (N.Chile). Although both volcanoes are related to the Central Andean magma systems, the geochemical characteristics of erupted materials from these two volcanoes represent distinct magmatic regimes and processes, occurring at depth of magma generation and storage (for details see Banaszak et al., this session). The lavas of Taapaca have relatively uniform dacitic compositions over a long period of volcanic activity (ca. 1270 ka) and low eruptive rates (0.024 km3/ka). In contrast, the rocks from Parinacota are younger (163 ka), and they have been produced in five stages of volcanic activity with eruptive rates that are at least one order of magnitude faster (0.5-1 km3/ka) than those of Taapaca.
    [Show full text]
  • RESEARCH Geochemistry and 40Ar/39Ar
    RESEARCH Geochemistry and 40Ar/39Ar geochronology of lavas from Tunupa volcano, Bolivia: Implications for plateau volcanism in the central Andean Plateau Morgan J. Salisbury1,2, Adam J.R. Kent1, Néstor Jiménez3, and Brian R. Jicha4 1COLLEGE OF EARTH, OCEAN, AND ATMOSPHERIC SCIENCES, OREGON STATE UNIVERSITY, CORVALLIS, OREGON 97331, USA 2DEPARTMENT OF EARTH SCIENCES, DURHAM UNIVERSITY, DURHAM DH1 3LE, UK 3UNIVERSIDAD MAYOR DE SAN ANDRÉS, INSTITUTO DE INVESTIGACIONES GEOLÓGICAS Y DEL MEDIO AMBIENTE, CASILLA 3-35140, LA PAZ, BOLIVIA 4DEPARTMENT OF GEOSCIENCE, UNIVERSITY OF WISCONSIN–MADISON, MADISON, WISCONSIN 53706, USA ABSTRACT Tunupa volcano is a composite cone in the central Andean arc of South America located ~115 km behind the arc front. We present new geochemical data and 40Ar/39Ar age determinations from Tunupa volcano and the nearby Huayrana lavas, and we discuss their petrogenesis within the context of the lithospheric dynamics and orogenic volcanism of the southern Altiplano region (~18.5°S–21°S). The Tunupa edifice was constructed between 1.55 ± 0.01 and 1.40 ± 0.04 Ma, and the lavas exhibit typical subduction signatures with positive large ion lithophile element (LILE) and negative high field strength element (HFSE) anomalies. Relative to composite centers of the frontal arc, the Tunupa lavas are enriched in HFSEs, particularly Nb, Ta, and Ti. Nb-Ta-Ti enrichments are also observed in Pliocene and younger monogenetic lavas in the Altiplano Basin to the east of Tunupa, as well as in rear arc lavas elsewhere on the central Andean Plateau. Nb concentrations show very little variation with silica content or other indices of differentiation at Tunupa and most other central Andean composite centers.
    [Show full text]
  • USGS Open-File Report 2009-1133, V. 1.2, Table 3
    Table 3. (following pages). Spreadsheet of volcanoes of the world with eruption type assignments for each volcano. [Columns are as follows: A, Catalog of Active Volcanoes of the World (CAVW) volcano identification number; E, volcano name; F, country in which the volcano resides; H, volcano latitude; I, position north or south of the equator (N, north, S, south); K, volcano longitude; L, position east or west of the Greenwich Meridian (E, east, W, west); M, volcano elevation in meters above mean sea level; N, volcano type as defined in the Smithsonian database (Siebert and Simkin, 2002-9); P, eruption type for eruption source parameter assignment, as described in this document. An Excel spreadsheet of this table accompanies this document.] Volcanoes of the World with ESP, v 1.2.xls AE FHIKLMNP 1 NUMBER NAME LOCATION LATITUDE NS LONGITUDE EW ELEV TYPE ERUPTION TYPE 2 0100-01- West Eifel Volc Field Germany 50.17 N 6.85 E 600 Maars S0 3 0100-02- Chaîne des Puys France 45.775 N 2.97 E 1464 Cinder cones M0 4 0100-03- Olot Volc Field Spain 42.17 N 2.53 E 893 Pyroclastic cones M0 5 0100-04- Calatrava Volc Field Spain 38.87 N 4.02 W 1117 Pyroclastic cones M0 6 0101-001 Larderello Italy 43.25 N 10.87 E 500 Explosion craters S0 7 0101-003 Vulsini Italy 42.60 N 11.93 E 800 Caldera S0 8 0101-004 Alban Hills Italy 41.73 N 12.70 E 949 Caldera S0 9 0101-01= Campi Flegrei Italy 40.827 N 14.139 E 458 Caldera S0 10 0101-02= Vesuvius Italy 40.821 N 14.426 E 1281 Somma volcano S2 11 0101-03= Ischia Italy 40.73 N 13.897 E 789 Complex volcano S0 12 0101-041
    [Show full text]
  • First Measurements of Gas Flux with a Low-Cost Smartphone Sensor-Based UV Camera on the Volcanoes of Northern Chile
    remote sensing Article First Measurements of Gas Flux with a Low-Cost Smartphone Sensor-Based UV Camera on the Volcanoes of Northern Chile Felipe Aguilera 1,2,3,* , Susana Layana 1,3,4 , Felipe Rojas 1 , Pilar Arratia 1, Thomas C. Wilkes 5 , Cristóbal González 1,4 , Manuel Inostroza 1,4 , Andrew J.S. McGonigle 5 , Tom D. Pering 5 and Gabriel Ureta 1,3,4 1 Núcleo de Investigación en Riesgo Volcánico—Ckelar Volcanes, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta 1270709, Chile; [email protected] (S.L.); [email protected] (F.R.); [email protected] (P.A.); [email protected] (C.G.); [email protected] (M.I.); [email protected] (G.U.) 2 Departamento de Ciencias Geológicas, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta 1270709, Chile 3 Centro de Investigación para la Gestión Integrada del Riesgo de Desastres (CIGIDEN), Av. Vicuña Mackenna 4860, Santiago 7810000, Chile 4 Programa de Doctorado en Ciencias mención Geología, Universidad Católica del Norte, Avenida Angamos 0610, Antofagasta 1270709, Chile 5 Department of Geography, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK; tcwilkes1@sheffield.ac.uk (T.C.W.); a.mcgonigle@sheffield.ac.uk (A.J.S.M.); t.pering@sheffield.ac.uk (T.D.P.) * Correspondence: [email protected] Received: 25 April 2020; Accepted: 29 June 2020; Published: 2 July 2020 Abstract: UV cameras have been used for over a decade in order to remotely sense SO2 emission rates from active volcanoes, and to thereby enhance our understanding of processes related to active and passive degassing.
    [Show full text]
  • Taapaca Volcanic Complex (North Chile) Versus El Misti Volcano (South Peru) Distinct Evolution of Two CVZ Volcanoes and a Comparison Based on U-Series Isotopes A
    Geophysical Research Abstracts, Vol. 7, 09923, 2005 SRef-ID: 1607-7962/gra/EGU05-A-09923 © European Geosciences Union 2005 Taapaca Volcanic Complex (North Chile) versus El Misti volcano (South Peru) distinct evolution of two CVZ volcanoes and a comparison based on U-series isotopes A. Kiebala (1), A. Heumann (1), G. Wörner (1) (1) GZG, Abt. Geochemie, Goldschmidtstr. 1, 37077 Göttingen, Germany Taapaca volcano (North Chile) and El Misti (South Peru) of the Central Andean Vol- canic Zone (CVZ) have been studied in order to place constraints on the evolution of their distinct magmatic systems. Taapaca is along-lived dome cluster (3,7 Ma to Holocene, Wörner et al., 2004; Clavero et al., 2004), which erupted magmas ranging between 60 and 71 wt%. However, the large majority (69%) of samples fall into the narrow range of 63 to 67wt% SiO2. By contrast, the composition of El Misti magmas shows a wider range between 58-68 wt% SiO2. Eruption rates at El Misti volcano are of 0.63-0.75m3/a based on a volume of 70- 83km3 and an age for the main stratocone of 112 ka (Thouret et al., 2000). Taapaca erupted 95km3 magma at a rate of 0,026m3/a during the 3.7 Ma maximum age of Taapaca (Wörner et al, 2004a). The two distinct volcanic systems are also very different in their U-Th disequilibria measured by TIMS. In fact, Th/U isotopic compositions of the Taapaca and El Misti volcanoes define the end members of the whole of CVZ: El Misti volcanics have very low (230Th/232Th) activity ratios of 0.32-0.40, possibly the lowest ever measured in volcanic rocks.
    [Show full text]
  • Magmatic Processes by U-Th Disequilibria Method
    Magmatic processes by U-Th disequilibria method. Comparison of two Andean systems: El Misti Volcano (S. Peru) and Taapaca Volcanic Center (N. Chile). Dissertation zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultäten der Georg-August-Universität zu Göttingen vorgelegt von Aneta Kiebala aus Rzeszów (Polen) Göttingen 2008 D 7 Referent: Prof. Dr. G. Wörner Korreferent: Prof. Dr. B. Hansen Tag der mündlichen Prüfung: 03.04.2008 2 Abstract El MistiVolcano (South Peru) and Taapaca Volcanic Complex (North Chile) both located in the Central Andean Volcanic Zone in South America have been studied in order to place constrains on the evolution of their distinct magmatic systems. Althought both volcanic ceneters are located in similar general geological settings (CVZ) they show very contrasting magmatic evolution. El Misti volcano is a single stratocone (<112ka, Thouret et al., 2001), which erupted magmas ranging between 58 and 68wt% SiO2. By contrast Taapaca is a long- lived dome cluster (1.27 Ma to Holocene, Wörner et al., 2004a; Clavero et al., 2004), which erupted magmas ranging between 60 and 71wt% SiO2. However the majority (69%) of samples fall into the narrow range of 63 to 67wt% SiO2. The radiogenic Sr-isotopic compositions are slightly higher for El Misti (0.7075-7078) than for Taapaca (0.7063-7067). Pb isotopic compositions are different, most likely reflecting the composition of assimilated continental crust (e.g. 206Pb/204Pb=17.68-17.84 for El Misti and 18.10 for Taapaca (Mamani et al., 2004)). The two studied volcanic systems are very different in their U-Th disequilibria measured by TIMS.
    [Show full text]