Constraints from U-Pb and Hf Isotopic Data of Detrital Zi
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Geologic Map of the Central San Juan Caldera Cluster, Southwestern Colorado by Peter W
Geologic Map of the Central San Juan Caldera Cluster, Southwestern Colorado By Peter W. Lipman Pamphlet to accompany Geologic Investigations Series I–2799 dacite Ceobolla Creek Tuff Nelson Mountain Tuff, rhyolite Rat Creek Tuff, dacite Cebolla Creek Tuff Rat Creek Tuff, rhyolite Wheeler Geologic Monument (Half Moon Pass quadrangle) provides exceptional exposures of three outflow tuff sheets erupted from the San Luis caldera complex. Lowest sheet is Rat Creek Tuff, which is nonwelded throughout but grades upward from light-tan rhyolite (~74% SiO2) into pale brown dacite (~66% SiO2) that contains sparse dark-brown andesitic scoria. Distinctive hornblende-rich middle Cebolla Creek Tuff contains basal surge beds, overlain by vitrophyre of uniform mafic dacite that becomes less welded upward. Uppermost Nelson Mountain Tuff consists of nonwelded to weakly welded, crystal-poor rhyolite, which grades upward to a densely welded caprock of crystal-rich dacite (~68% SiO2). White arrows show contacts between outflow units. 2006 U.S. Department of the Interior U.S. Geological Survey CONTENTS Geologic setting . 1 Volcanism . 1 Structure . 2 Methods of study . 3 Description of map units . 4 Surficial deposits . 4 Glacial deposits . 4 Postcaldera volcanic rocks . 4 Hinsdale Formation . 4 Los Pinos Formation . 5 Oligocene volcanic rocks . 5 Rocks of the Creede Caldera cycle . 5 Creede Formation . 5 Fisher Dacite . 5 Snowshoe Mountain Tuff . 6 Rocks of the San Luis caldera complex . 7 Rocks of the Nelson Mountain caldera cycle . 7 Rocks of the Cebolla Creek caldera cycle . 9 Rocks of the Rat Creek caldera cycle . 10 Lava flows premonitory(?) to San Luis caldera complex . .11 Rocks of the South River caldera cycle . -
Muntean/Einaudi
Economic Geology Vol. 95, 2000, pp. 1445–1472 Porphyry Gold Deposits of the Refugio District, Maricunga Belt, Northern Chile JOHN L. MUNTEAN†,* AND MARCO T. EINAUDI Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305-2115 Abstract The porphyry gold deposits of the Refugio district and similar deposits in the Maricunga belt contain the lowest known copper to gold ratios (% Cu/ppm Au = ~0.03) of any porphyry-type deposit. The gold deposits are associated with subvolcanic andesitic to dacitic intrusions emplaced into coeval volcanic rocks. Both the Verde and Pancho deposits are zoned in space from a deeper zone of banded quartz veinlets associated with chlorite-magnetite-albite and/or pyrite-albite-clay alteration to a shallow zone of pyrite-albite-clay and local quartz-alunite ledges. Pancho contains an additional, deepest, porphyry copperlike zone, with quartz veinlets (A-veinlets) and potassic alteration. Relative to Verde, Pancho is telescoped, with all three zones present within a 400-m-vertical interval. The porphyry copperlike zone at Pancho is characterized by A-veinlets and pervasive potassic alteration, both restricted to intrusive rocks. A-veinlets range from hairline streaks of magnetite ± biotite with minor quartz and chalcopyrite, and K feldspar alteration envelopes to sugary quartz veinlets <1 cm in width with mag- netite and chalcopyrite and no alteration envelopes. Hypersaline liquid inclusions coexisting with vapor-rich in- clusions indicate temperatures above 600°C and salinities as high as 84 wt percent NaCl equiv. A pressure es- timate of 250 bars indicates a depth of 1,000 m, assuming lithostatic pressure. -
Assembly, Configuration, and Break-Up History of Rodinia
Author's personal copy Available online at www.sciencedirect.com Precambrian Research 160 (2008) 179–210 Assembly, configuration, and break-up history of Rodinia: A synthesis Z.X. Li a,g,∗, S.V. Bogdanova b, A.S. Collins c, A. Davidson d, B. De Waele a, R.E. Ernst e,f, I.C.W. Fitzsimons g, R.A. Fuck h, D.P. Gladkochub i, J. Jacobs j, K.E. Karlstrom k, S. Lu l, L.M. Natapov m, V. Pease n, S.A. Pisarevsky a, K. Thrane o, V. Vernikovsky p a Tectonics Special Research Centre, School of Earth and Geographical Sciences, The University of Western Australia, Crawley, WA 6009, Australia b Department of Geology, Lund University, Solvegatan 12, 223 62 Lund, Sweden c Continental Evolution Research Group, School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia d Geological Survey of Canada (retired), 601 Booth Street, Ottawa, Canada K1A 0E8 e Ernst Geosciences, 43 Margrave Avenue, Ottawa, Canada K1T 3Y2 f Department of Earth Sciences, Carleton U., Ottawa, Canada K1S 5B6 g Tectonics Special Research Centre, Department of Applied Geology, Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia h Universidade de Bras´ılia, 70910-000 Bras´ılia, Brazil i Institute of the Earth’s Crust SB RAS, Lermontova Street, 128, 664033 Irkutsk, Russia j Department of Earth Science, University of Bergen, Allegaten 41, N-5007 Bergen, Norway k Department of Earth and Planetary Sciences, Northrop Hall University of New Mexico, Albuquerque, NM 87131, USA l Tianjin Institute of Geology and Mineral Resources, CGS, No. -
Field Excursion Report 2010
Presented at “Short Course on Geothermal Drilling, Resource Development and Power Plants”, organized by UNU-GTP and LaGeo, in Santa Tecla, El Salvador, January 16-22, 2011. GEOTHERMAL TRAINING PROGRAMME LaGeo S.A. de C.V. GEOTHERMAL ACTIVITY AND DEVELOPMENT IN SOUTH AMERICA: SHORT OVERVIEW OF THE STATUS IN BOLIVIA, CHILE, ECUADOR AND PERU Ingimar G. Haraldsson United Nations University Geothermal Training Programme Orkustofnun, Grensasvegi 9, 108 Reykjavik ICELAND [email protected] ABSTRACT South America holds vast stores of geothermal energy that are largely unexploited. These resources are largely the product of the convergence of the South American tectonic plate and the Nazca plate that has given rise to the Andes mountain chain, with its countless volcanoes. High-temperature geothermal resources in Bolivia, Chile, Ecuador and Peru are mainly associated with the volcanically active regions, although low temperature resources are also found outside them. All of these countries have a history of geothermal exploration, which has been reinvigorated with recent changes in global energy prices and the increased emphasis on renewables to combat global warming. The paper gives an overview of their main regions of geothermal activity and the latest developments in the geothermal sector are reviewed. 1. INTRODUCTION South America has abundant geothermal energy resources. In 1999, the Geothermal Energy Association estimated the continent’s potential for electricity generation from geothermal resources to be in the range of 3,970-8,610 MW, based on available information and assuming the use of technology available at that time (Gawell et al., 1999). Subsequent studies have put the potential much higher, as a preliminary analysis of Chile alone assumes a generation potential of 16,000 MW for at least 50 years from geothermal fluids with temperatures exceeding 150°C, extracted from within a depth of 3,000 m (Lahsen et al., 2010). -
Counterclockwise Rotation of Late Eocene – Oligocene Forearc Deposits in Southern Peru and Its Significance for Oroclinal Bend
Counterclockwise rotation of Late Eocene – Oligocene forearc deposits in southern Peru and its significance for oroclinal bending in the Central Andes Pierrick Roperch, Thierry Sempere, Orlando Macedo, César Arriagada, Michel Fornari, Claudio Tapia, Marcelo Garcia, Carlo Laj To cite this version: Pierrick Roperch, Thierry Sempere, Orlando Macedo, César Arriagada, Michel Fornari, et al.. Coun- terclockwise rotation of Late Eocene – Oligocene forearc deposits in southern Peru and its significance for oroclinal bending in the Central Andes. Tectonics, American Geophysical Union (AGU), 2006, 25 (3), pp.TC3010. 10.1029/2005TC001882. insu-00261209 HAL Id: insu-00261209 https://hal-insu.archives-ouvertes.fr/insu-00261209 Submitted on 29 Jun 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. TECTONICS, VOL. 25, TC3010, doi:10.1029/2005TC001882, 2006 Counterclockwise rotation of late Eocene–Oligocene fore-arc deposits in southern Peru and its significance for oroclinal bending in the central Andes Pierrick Roperch,1,2 Thierry Sempere,3 Orlando Macedo,4 Ce´sar Arriagada,2 Michel Fornari,5 Claudio Tapia,2 Marcelo Garcı´a,6 and Carlo Laj7 Received 6 July 2005; revised 20 February 2006; accepted 14 March 2006; published 1 June 2006. -
Plateau-Style Accumulation of Deformation: Southern Altiplano
TECTONICS, VOL. 24, TC4020, doi:10.1029/2004TC001675, 2005 Plateau-style accumulation of deformation: Southern Altiplano Kirsten Elger, Onno Oncken, and Johannes Glodny GeoForschungsZentrum Potsdam, Potsdam, Germany Received 5 May 2004; revised 17 December 2004; accepted 23 March 2005; published 31 August 2005. [1] Employing surface mapping of syntectonic during the Paleogene, initially reactivating crustal sediments, interpretation of industry reflection- weak zones and by thermal weakening of the crust seismic profiles, gravity data, and isotopic age dating, with active magmatism mainly in the Neogene stage. we reconstruct the tectonic evolution of the southern Citation: Elger, K., O. Oncken, and J. Glodny (2005), Plateau- Altiplano (20–22°S) between the cordilleras style accumulation of deformation: Southern Altiplano, Tectonics, defining its margins. The southern Altiplano crust 24, TC4020, doi:10.1029/2004TC001675. was deformed between the late Oligocene and the late Miocene with two main shortening stages in the Oligocene (33–27 Ma) and middle/late Miocene 1. Introduction (19–8 Ma) that succeeded Eocene onset of shortening at the protoplateau margins. Shortening [2] Although considerable advance has been made in recent years in understanding the processes involved in rates in the southern Altiplano ranged between 1 and the formation of orogenic plateaus, the precise temporal 4.7 mm/yr with maximum rates in the late Miocene. and spatial patterns of uplift and lateral progradation of Summing rates for the southern Altiplano and the -
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. -
Full-Text PDF (Final Published Version)
Pritchard, M. E., de Silva, S. L., Michelfelder, G., Zandt, G., McNutt, S. R., Gottsmann, J., West, M. E., Blundy, J., Christensen, D. H., Finnegan, N. J., Minaya, E., Sparks, R. S. J., Sunagua, M., Unsworth, M. J., Alvizuri, C., Comeau, M. J., del Potro, R., Díaz, D., Diez, M., ... Ward, K. M. (2018). Synthesis: PLUTONS: Investigating the relationship between pluton growth and volcanism in the Central Andes. Geosphere, 14(3), 954-982. https://doi.org/10.1130/GES01578.1 Publisher's PDF, also known as Version of record License (if available): CC BY-NC Link to published version (if available): 10.1130/GES01578.1 Link to publication record in Explore Bristol Research PDF-document This is the final published version of the article (version of record). It first appeared online via Geo Science World at https://doi.org/10.1130/GES01578.1 . Please refer to any applicable terms of use of the publisher. University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ Research Paper THEMED ISSUE: PLUTONS: Investigating the Relationship between Pluton Growth and Volcanism in the Central Andes GEOSPHERE Synthesis: PLUTONS: Investigating the relationship between pluton growth and volcanism in the Central Andes GEOSPHERE; v. 14, no. 3 M.E. Pritchard1,2, S.L. de Silva3, G. Michelfelder4, G. Zandt5, S.R. McNutt6, J. Gottsmann2, M.E. West7, J. Blundy2, D.H. -
Redalyc.Geochemistry, U-Pb SHRIMP Zircon Dating and Hf Isotopes of The
Andean Geology ISSN: 0718-7092 [email protected] Servicio Nacional de Geología y Minería Chile Poma, Stella; Zappettini, Eduardo O.; Quenardelle, Sonia; Santos, João O.; Koukharsky, Magdalena; Belousova, Elena; McNaughton, Neil Geochemistry, U-Pb SHRIMP zircon dating and Hf isotopes of the Gondwanan magmatism in NW Argentina: petrogenesis and geodynamic implications Andean Geology, vol. 41, núm. 2, mayo, 2014, pp. 267-292 Servicio Nacional de Geología y Minería Santiago, Chile Available in: http://www.redalyc.org/articulo.oa?id=173931252001 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 (2): 267-292. May, 2014 Andean Geology doi: 10.5027/andgeoV41n2-a01 formerly Revista Geológica de Chile www.andeangeology.cl Geochemistry, U-Pb SHRIMP zircon dating and Hf isotopes of the Gondwanan magmatism in NW Argentina: petrogenesis and geodynamic implications Stella Poma1, Eduardo O. Zappettini 2, Sonia Quenardelle 1, João O. Santos 3, † Magdalena Koukharsky 1, Elena Belousova 4, Neil McNaughton 3 1 Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires (IGEBA-CONICET), Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Ciencias Geológicas, Pabellón II-Ciudad Universitaria, Intendente Güiraldes 2160, C1428 EGA, Argentina. [email protected]; [email protected] 2 Servicio Geológico Minero Argentino (SEGEMAR), Avda. General Paz 5445, edificio 25, San Martín B1650WAB, Argentina. [email protected] 3 University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia. -
Geology, Petrology and Geochemical Characteristics of Alteration Zones Within the Seridune Prospect, Kerman, Iran
Geology, petrology and geochemical characteristics of alteration zones within the Seridune prospect, Kerman, Iran Von der Fakultät für Georessourcen und Materialtechnik der Rheinisch-Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von M.Sc. Hassan Barzegar aus Shiraz, Iran Berichter: Univ.-Prof. Dr.rer.nat. Franz Michael Meyer Univ.-Prof. Dr.rer.nat. Ulrich Kramm Tag der mündlichen Prüfung: 27. August 2007 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar For Melika and Mojan FOREWORD This research project was fully facilitated by the Institute of Mineralogy and Economic Geology, Rheinisch Westfälischen Technischen Hochschule (RWTH) Aachen University and supported by the Research Department of National Iranian Copper Industries Company (NICICO). The Institute of Mineralogy and Economic Geology, RWTH Aachen University sponsored sample preparations and geochemical analyses. First, I would like to thank my supervisor, Prof. Dr. F. Michael Meyer, Head of the Department of Mineralogy and Economic Geology, RWTH Aachen University, for his worthy support, guidance, continued interest, encouragement during this work, and for many hours of his time spent in discussions; Dr. Jochen Kolb who gave me guidance and encouragement through each stage of the work, for his interest, time spent in discussions and proof-reading this thesis; Annika Dziggel, Ph.D for her assistance and discussion and Dr. Sven Sindern for his support and assistance in XRF analyses. This thesis is also benefited by the suggestions and guidance of Prof. Dr. Ulrich Kramm and Prof. Dr. Helge Stanjek. Their interests are highly appreciated. My sincere thanks go to manager of Exploration Office, Dr. -
Late Mesozoic to Paleogene Stratigraphy of the Salar De Atacama Basin, Antofagasta, Northern Chile: Implications for the Tectonic Evolution of the Central Andes
Late Mesozoic to Paleogene stratigraphy of the Salar de Atacama Basin, Antofagasta, Northern Chile: Implications for the tectonic evolution of the Central Andes Constantino Mpodozisa,T,Ce´sar Arriagadab, Matilde Bassoc, Pierrick Roperchd, Peter Cobbolde, Martin Reichf aServicio Nacional de Geologı´a y Minerı´a, now at Sipetrol. SA, Santiago, Chile bDepartamento de Geologı´a, Universidad de Chile, Santiago, Chile cServicio Nacional de Geologı´a y Minerı´a, Santiago, Chile dIRD/Dep. de Geologı´a, Universidad de Chile, Santiago, Chile eGe´osciences-Rennes (UMR6118 du CNRS), France fDepartment of Geological Sciences University of Michigan, United States Abstract The Salar de Atacama basin, the largest bpre-AndeanQ basin in Northern Chile, was formed in the early Late Cretaceous as a consequence of the tectonic closure and inversion of the Jurassic–Early Cretaceous Tarapaca´ back arc basin. Inversion led to uplift of the Cordillera de Domeyko (CD), a thick-skinned basement range bounded by a system of reverse faults and blind thrusts with alternating vergence along strike. The almost 6000-m-thick, upper Cretaceous to lower Paleocene sequences (Purilactis Group) infilling the Salar de Atacama basin reflects rapid local subsidence to the east of the CD. Its oldest outcropping unit (Tonel Formation) comprises more than 1000 m of continental red sandstones and evaporites, which began to accumulate as syntectonic growth strata during the initial stages of CD uplift. Tonel strata are capped by almost 3000 m of sandstones and conglomerates of western provenance, representing the sedimentary response to renewed pulses of tectonic shortening, which were deposited in alluvial fan, fluvial and eolian settings together with minor lacustrine mudstone (Purilactis Formation). -
A Structural and Geochronological Study of Tromen Volcano
Volcanism in a compressional Andean setting: A structural and geochronological study of Tromen volcano (Neuqu`enprovince, Argentina) Olivier Galland, Erwan Hallot, Peter Cobbold, Gilles Ruffet, Jean De Bremond d'Ars To cite this version: Olivier Galland, Erwan Hallot, Peter Cobbold, Gilles Ruffet, Jean De Bremond d'Ars. Vol- canism in a compressional Andean setting: A structural and geochronological study of Tromen volcano (Neuqu`enprovince, Argentina). Tectonics, American Geophysical Union (AGU), 2007, 26 (4), pp.TC4010. <10.1029/2006TC002011>. <insu-00180007> HAL Id: insu-00180007 https://hal-insu.archives-ouvertes.fr/insu-00180007 Submitted on 29 Jun 2016 HAL is a multi-disciplinary open access L'archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destin´eeau d´ep^otet `ala diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publi´esou non, lished or not. The documents may come from ´emanant des ´etablissements d'enseignement et de teaching and research institutions in France or recherche fran¸caisou ´etrangers,des laboratoires abroad, or from public or private research centers. publics ou priv´es. TECTONICS, VOL. 26, TC4010, doi:10.1029/2006TC002011, 2007 Volcanism in a compressional Andean setting: A structural and geochronological study of Tromen volcano (Neuque´n province, Argentina) Olivier Galland,1,2 Erwan Hallot,1 Peter R. Cobbold,1 Gilles Ruffet,1 and Jean de Bremond d’Ars1 Received 28 June 2006; revised 6 February 2007; accepted 16 March 2007; published 2 August 2007. [1] We document evidence for growth of an active [3] In contrast, a context of crustal thickening, where the volcano in a compressional Andean setting.