DOCSLIB.ORG

Geochemical Behavior and Emplacement Conditions of the Ibagué Batholith: Regional Implications

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geochemical Behavior and Emplacement Conditions of the Ibagué Batholith: Regional Implications GEOCHEMICAL BEHAVIOR AND EMPLACEMENT CONDITIONS OF THE IBAGUÉ BATHOLITH: REGIONAL IMPLICATIONS EDGAR ALEJANDRO CORTÉS CALDERÓN UNIVERSIDAD DE LOS ANDES FACULTAD DE CIENCIAS DEPARTAMENTO DE GEOCIENCIAS BOGOTÁ D.C – 2015 1 2 GEOCHEMICAL BEHAVIOR AND EMPLACEMENT CONDITIONS OF THE IBAGUÉ BATHOLITH: REGIONAL IMPLICATIONS EDGAR ALEJANDRO CORTÉS CALDERÓN Trabajo de grado para optar al título de: Geocientífico Director: IDAEL FRANCISCO BLANCO QUINTERO, PhD. UNIVERSIDAD DE LOS ANDES FACULTAD DE CIENCIAS DEPARTAMENTO DE GEOCIENCIAS BOGOTÁ D.C - 2015 3 4 Agradecimientos En primer lugar, quiero agradecer a mi director de tesis Dr. Idael Francisco Blanco Quintero por su apoyo, consejos y enseñanzas durante el tiempo que lo conozco, por las oportunidades que me ha dado, por mostrarme que con esfuerzo y dedicación se pueden lograr los objetivos que uno se propone, obviamente sin olvidar las risas y los buenos momentos. También, quiero agradecer al profesor Dr. Camilo Montes Rodríguez, un excelente investigador, por motivarme a querer estudiar esta carrera y tener pasión por la ciencia. A la Beca para tesis de pregrado financiada por el Fondo Corrigan-ACGGP- ARES y al fondo FAPA del Dr. Idael Blanco otorgado por la Vicerrectoría de Investigación de la Universidad de los Andes, cuyo apoyo económico permitió la realización de esta investigación. A mis padres, quienes me han apoyado y acompañado en todos mis objetivos. Gracias por el esfuerzo que han realizado para darme todas las comodidades y oportunidades que he tenido hasta ahora. A mis viejitos, Julio y Blanca por sus cariños, sus cuidados y ser mi ejemplo de vida. A mi hermano Santiago y a toda mi familia, por los buenos momentos y las enseñanzas que me han dejado hasta ahora. A mis amigos y compañeros con los que he compartido buenas experiencias, logros personales y académicos. Gracias por la compañía y consejos tanto en los buenos momentos como en los difíciles, por las retroalimentaciones y ayudas a este proyecto. Muchas gracias a todos. 5 6 INDEX 1. Abstract .................................................................................................................................... 9 2. Introduction ........................................................................................................................... 13 2.1 The origin of granitoid magmas .......................................................................................... 13 2.2 Emplacement of large volumes of magma ..................................................................... 14 2.3 Jurassic Subduction at northern Andes .......................................................................... 15 3. Regional geology ................................................................................................................ 16 4. Methodology and Analytical techniques .................................................................. 20 4.1 Whole-rock chemistry ............................................................................................................. 21 4.2 Microprobe analyses ............................................................................................................... 23 4.3 Thermobarometric analyses ................................................................................................. 24 4.4 Crystallization modelling ........................................................................................................ 25 5. Results .................................................................................................................................... 25 5.1 Whole rock composition ........................................................................................................ 25 5.2 Petrology ....................................................................................................................................... 29 5.2.1 Petrography ............................................................................................................................................ 29 5.2.2 Mineral chemistry ................................................................................................................................ 30 5.2.3 X-ray maps ............................................................................................................................................. 38 5.2.4 P-T crystallization conditions ........................................................................................................ 40 5.2.5 MELTS modelling ................................................................................................................................ 41 6. Discussion ............................................................................................................................. 42 6.1 Origin of the magma ................................................................................................................. 42 6.2 Regional implications .............................................................................................................. 44 7. Conclusions .......................................................................................................................... 45 8. References ............................................................................................................................ 46 7 8 1. Abstract The Ibagué batholith is a heterogeneous I-type granitoid located along the Cordillera Central of Colombia. It consists of many magmatic pulses that crystallized along Jurassic times (150-188 Ma). This work reports new geochemical and petrologic features from the Ibagué batholith in an area next to Coello river west of the town of Ibagué. The petrography and mineral chemistry of the samples show a mineral assemblage that consists of plagioclase (Oligoclase to Andesine) + quartz + amphibole (Edenite and Mg- Hornblende) + biotite (Fe-Biotite) as the main minerals, K-feldspar (Sanidine) + pyroxene (Diopside) as minor phases, and chlorite (Ripidolite-Pycnochlorite) + epidote as alteration products. Whole-rock geochemistry indicates a volcanic arc affinity that suggests melting of a metasomatized mantle wedge and assimilation of continental crust based on Y = 12.76-20.03 ppm, Yb = 1.15-1.78 ppm, Nb = 6.25-8.74 ppm, and Ba/Nb ratios = 73.11- 160.41. The Edenite-Andesine pair suggests maximum emplacement depth at 8.2-10.5 km (i.e. 2.5-3.2 Kbar and 750-850ºC). Therefore, Cajamarca and Tierradentro metamorphic complexes, and Payande limestones were located at this depth in order to be intruded when the batholith was emplaced. Furthermore, liquidus was found at 1074 ºC and 15 kbar using Rhyolite-Melts software. The thermodynamic models show that diopsidic pyroxenes should be xenocrystals and the order of crystallization was horblende-feldspars-biotite- quartz. Key words: Mineral Chemistry, Thermobarometry, X-ray maps, Ibagué batholith. 9 10 Resumen El batolito de Ibagué es un granitoide heterogéneo tipo-I ubicado a lo largo de la Cordillera Central de Colombia, el cual es el resultado de varios pulsos magmáticos que cristalizaron durante el Jurásico (150-188 Ma). Este trabajo reporta nuevos datos geoquímicos y petrológicos para el batolito de Ibagué en un área cerca al rio Coello (i.e. al oeste de la ciudad de Ibagué). La petrografía y química mineral de las muestras analizadas muestran una asociación de fases que consiste de plagioclasa (oligoclase-andesina) + cuarzo + anfíbol (edenite – Mg-Hornblenda) + biotita (Fe-Biotita) como minerales princiaples, feldespato potásico (Sanidina) + piroxeno (Diópsido) como fases secundarias, y clorita (ripidolite-picnoclorita) + epidota como productos de alteración. La geoquímica de roca total indica una afinidad de arco volcánico, lo cual sugiere un magma proveniente de una cuña mantélica metasomatizada por la infiltración de fluidos de la losa oceánica que subduce debajo de esta y una asimilación de corteza continental, basándose en Y = 12.76-20.03 ppm, Yb = 1.15-1.78 ppm, Nb = 6.25-8.74 ppm, and Ba/Nb ratios = 73.11- 160.41. Adicionalmente, parejas minerals de edenita-andesina sugieren una profundidad de emplazamiento máxima a 8.2-10.5 km (i.e. 2.5-3.2 kbar y 750-850ºC), donde se encontrarían los cuerpos intruidos por el batolito durante su emplazamiento. El liquidus fue encontrado a 1074 ºC y 15 kbar asumiendo la composición de roca total como parámetro de entrada para el fundido y solo las fases minerals observadas en las secciones delgadas como posibles productos de la cristalización. Como consecuencia, el modelo obtenido en el software Rhyolite-Melts sugiere que los piroxénos diopsídicos encontrados no proceden de la cristalización del magma, sino que deberían ser xenocristales. Palabras clave: Química mineral, Termobarometría, Mapas de rayos X, batolito de Ibagué. 11 12 2. Introduction Batholiths are the result of crystallization of large magma volumes emplaced in the crust. Although batholiths can be viewed as monotonous bodies, the origin and evolution of these rocks are still a matter of debate (Castro, 2014). Nowadays, the application of advanced tools within petrology, structural geology and geophysics give more information about batholiths, then the thermal structure of the mantle and tectonic settings can be improved (i.e. Castro, 2014; Taylor and McLennan, 1995). These batholith bodies have variable composition, predominantly intermediate to acid values in silica content and thus they are called granitoids. 2.1 The origin of granitoid magmas There are both on- and off- crust
Load more

Recommended publications
  • Late Cretaceous to Cenozoic Uplift of the Northern Andes: Paleogeographic Implications
    Volume 3 Quaternary Chapter 4 Neogene https://doi.org/10.32685/pub.esp.37.2019.04 Published online 26 November 2020 Late Cretaceous to Cenozoic Uplift of the Paleogene Northern Andes: Paleogeographic Implications Andrés MORA1 , Diego VILLAGÓMEZ2 , Mauricio PARRA3 , 1 [email protected] Ecopetrol, Brasil 4 5 6 Cretaceous Víctor M. CABALLERO , Richard SPIKINGS , Brian K. HORTON , Bogotá, Colombia 7 8 2 [email protected] Josué Alejandro MORA–BOHÓRQUEZ , Richard A. KETCHAM , University of Geneva 9 and Juan Pablo ARIAS–MARTÍNEZ Department of Earth Science Rue des Maraîchers13. CH–1205 Geneva, Switzerland Abstract In this chapter, we summarize recent work on the geologic evolution of the Jurassic 3 [email protected] northern Andes. Our intention is to present current information so that scientists Universidade de São Paulo Instituto de Energia e Ambiente from other disciplines can differentiate data from interpretations. In this effort, we Av. Professor Luciano Gualberto 1289, Cidade focus on thermochronological data that provide precise places, dates, and rates. Universitária, 05508–010 São Paulo, Brasil Thermochronological data provide cooling histories for rocks of the upper crust, 4 [email protected] Triassic whereas provenance data offer insights on rocks that have been eroded away. In Ecopetrol S.A. Instituto Colombiano del Petróleo reviewing published data, we provide a critical overview of recent paleogeographic Centro de Innovación y Tecnología interpretations. Specifically, we discuss hypotheses such as (i) Eocene proto–Magda- Km7 via Bucaramanga–Piedecuesta Piedecuesta–Santander, Colombia lena River draining toward the Maracaibo Basin, (ii) the presence of a closed proto– 5 [email protected] Magdalena basin from the late Eocene to middle Miocene, (iii) the Miocene closure of University of Geneva Permian Department of Earth Sciences and the the Isthmus of Panamá, (iv) the late Cenozoic surface uplift of the Eastern Cordillera, Environment and (v) the Cenozoic eastward advance of the Orinoco River.
    [Show full text]
  • Structural Evolution of the Northernmost Andes, Colombia
    Structural Evolution of the Northernmost Andes, Colombia GEOLOGICAL SURVEY PROFESSIONAL PAPER 846 Prepared in coopeTation ·with the lnstituto Nacional de Investigaciones Geologico-MineTas under the auspices of the Government of Colombia and the Agency for International Development) United States DepaTtment of State Structural Evolution of the Northernmost Andes, Colombia By EARL M. IRVING GEOLOGICAL SURVEY PROFESSIONAL PAPER 846 Prepared in cooperation ·with the lnstituto Nacional de Investigaciones Geologico-Min eras under the auspices of the Government of Colombia and the Agency for International Development) United States Department of State An interpretation of the geologic history of a complex mountain system UNITED STATES GOVERNlVIENT PRINTING OFFICE, vVASHINGTON 1975 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress Cataloging in Publication Data Irving, Earl Montgomery, 1911- Structural evolution of the northernmost Andes, Columbia. (Geological Survey professional paper ; 846) Bibliography: p Includes index. Supt. of Docs. no.: I 19.16:846 1. Geology-Colombia. 2. Geosynclines----Colombia. I. Instituto Nacional de Investigaciones Geologico­ Mineras.. II. Title. III. Series: United States. Geological Survey. Professional paper ; 846. QE239.175 558.61 74-600149 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402- Price $1.30 (paper cover) Stock Number 2401-02553 CONTENTS Page Pasre Abstract ----------------------------------------
    [Show full text]
  • Evaluación Probabilística De La Amenaza Sísmica Regional Para La Ciudad De Ibagué
    Universidad de La Salle Ciencia Unisalle Ingeniería Civil Facultad de Ingeniería 2007 Evaluación probabilística de la amenaza sísmica regional para la ciudad de Ibagué Mario Cesar Romero López Universidad de La Salle, Bogotá Follow this and additional works at: https://ciencia.lasalle.edu.co/ing_civil Part of the Civil Engineering Commons Citación recomendada Romero López, M. C. (2007). Evaluación probabilística de la amenaza sísmica regional para la ciudad de Ibagué. Retrieved from https://ciencia.lasalle.edu.co/ing_civil/180 This Trabajo de grado - Pregrado is brought to you for free and open access by the Facultad de Ingeniería at Ciencia Unisalle. It has been accepted for inclusion in Ingeniería Civil by an authorized administrator of Ciencia Unisalle. For more information, please contact [email protected]. EVALUACIÓN PROBABILÍSTICA DE LA AMENAZA SÍSMICA REGIONAL PARA LA CIUDAD DE IBAGUÉ MARIO CESAR ROMERO LÓPEZ UNIVERSIDAD DE LA SALLE FACULTAD DE INGENIERÍA CIVIL BOGOTÁ D.C. 2007 EVALUACIÓN PROBABILÍSTICA DE LA AMENAZA SÍSMICA REGIONAL PARA LA CIUDAD DE IBAGUÉ MARIO CESAR ROMERO LÓPEZ Trabajo de grado presentado como requisito parcial para optar al título de Ingeniero Civil Director Andrés José Alfaro Castillo Asesora metodológica Mag. Rosa Amparo Ruiz Saray UNIVERSIDAD DE LA SALLE FACULTAD DE INGENIERÍA CIVIL BOGOTÁ D.C. 2007 Nota de aceptación: _________________________________________ _________________________________________ _________________________________________ _________________________________________ _________________________________________
    [Show full text]
  • Influencia De La Actividad Tectónica Y Volcánica Reciente En La Dinámica Fluvial Del Río Anaime (Cajamarca, Cordillera Central De Colombia)
    Boletín de Geología ISSN: 0120-0283 ISSN: 2145-8553 Universidad Industrial de Santander Influencia de la actividad tectónica y volcánica reciente en la dinámica fluvial del río Anaime (Cajamarca, Cordillera Central de Colombia) García-Delgado, Helbert; Machuca, Silvia Influencia de la actividad tectónica y volcánica reciente en la dinámica fluvial del río Anaime (Cajamarca, Cordillera Central de Colombia) Boletín de Geología, vol. 41, núm. 3, 2019 Universidad Industrial de Santander Disponible en: http://www.redalyc.org/articulo.oa?id=349664643005 DOI: 10.18273/revbol.v41n3-2019003 PDF generado a partir de XML-JATS4R por Redalyc Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Artículos científicos Influencia de la actividad tectónica y volcánica reciente en la dinámica fluvial del río Anaime (Cajamarca, Cordillera Central de Colombia) Recent tectonic and volcanic influence on the fluvial dynamics of the Anaime River (Cajamarca, Central Cordillera of Colombia) Helbert García-Delgado 1* Servicio Geológico Colombiano, Colombia ORCID: hp://orcid.org/0000-0002-7714-7161 Silvia Machuca 1 [email protected] Servicio Geológico Colombiano, Colombia ORCID: hp://orcid.org/0000-0002-1052-4647 Boletín de Geología, vol. 41, núm. 3, 2019 Universidad Industrial de Santander RESUMEN: El valle del río Anaime, localizado en la parte central de la Cordillera Recepción: 28 Diciembre 2018 Central, se encuentra en una zona con influencia tectónica importante por estructuras Aprobación: 03 Julio 2019 regionales que hacen parte de los Sistemas de Fallas de Palestina e Ibagué. Además de DOI: 10.18273/revbol.v41n3-2019003 lo anterior, esta zona ha estado bajo influencia de eventos volcánicos regionales como producto de la actividad reciente durante los últimos 5000 años del Volcán Cerro CC BY Machín.
    [Show full text]
  • Stratigraphy of the Ordovician La Cristalina Formation, Puerto Berrío (Colombia)
    ____________________________ Director Doc. Rer. Nat., P.Doc. Pedro Calixto Patarroyo Gama ____________________________ Codirector Ph.D. José María Jaramillo Mejía II Stratigraphy of the Ordovician La Cristalina Formation, Puerto Berrío (Colombia) Stratigraphy of the Ordovician La Cristalina Formation, Puerto Berrío (Colombia) María Fernanda Almanza Meléndez Geologist, Universidad Nacional de Colombia Sede Bogotá Universidad Nacional de Colombia Facultad de Ciencias, Departamento de Geociencias Bogotá D. C., Colombia 2017 Stratigraphy of the Ordovician La Cristalina Formation, Puerto Berrío (Colombia) María Fernanda Almanza Meléndez Geologist, Universidad Nacional de Colombia-Sede Bogotá Thesis presented as partial requisite to get the title of: Mágister en Ciencias-Geología Director: Doc. Rer. Nat., P.Doc. Pedro Calixto Patarroyo Gama Co-Director: Ph.D. José María Jaramillo Mejía Research field: Stratigraphy Universidad Nacional de Colombia Facultad de Ciencias, Departamento de Geociencias Bogotá D. C., Colombia 2017 To those who enjoy each piece of the cake, who love researching and never forget to be a good human being. To my beloved father, mother and brother Acknowledgments The main reason to do this master theses was the curiosity I had for some poorly-known old rocks. So, I feel deeply grateful with those Ordovician complicated rocks for allowing me discover something new. I am grateful with my advisor Pedro Patarroyo for accompanings me during field work, and with my co-advisor professor José María Jaramillo, firstly, for the enlightining discussions during the best researching-breakfasts, secondly for guiding me to unlock dreams and build this master theses and its related peer-reviewed publications, lastly for introducing me to such metamorphic rocks and to encourage me to study them.
    [Show full text]
  • Fragments of a Permian Arc on the Western Margin of the Neoproterozoic Basement of Colombia a Gguajirauajira 78° W 75° W 72° W Regionregion Caribbean Sea Cuisa Fault
    Volume 1 Quaternary Chapter 10 Neogene https://doi.org/10.32685/pub.esp.35.2019.10 Fragments of a Permian Arc on the Western Published online 26 September 2019 Margin of the Neoproterozoic Basement of Colombia Paleogene Gabriel RODRÍGUEZ–GARCÍA1* , Ana María CORREA–MARTÍNEZ2 , 1 [email protected] Servicio Geológico Colombiano 3 4 Juan Pablo ZAPATA–VILLADA , and Gloria OBANDO–ERAZO Dirección de Geociencias Básicas Grupo de Estudios Geológicos Especiales Cretaceous Calle 75 n.° 79A–51 Abstract New petrographic, whole–rock geochemical, and U–Pb–zircon geochro- Medellín, Colombia nologic data combined with data from previous studies enabled identification of 2 [email protected] a fragmented Permian magmatic arc with ages ranging from 294 to 260 Ma in the Servicio Geológico Colombiano Dirección de Geociencias Básicas Colombian Andes. The arc is exposed along the southeastern slope of the Central Grupo de Estudios Geológicos Especiales Calle 75 n.° 79A–51 Jurassic Cordillera towards the Upper Magdalena Valley, serranía de San Lucas, and Sierra Medellín, Colombia Nevada de Santa Marta. 3 [email protected] Servicio Geológico Colombiano The arc fragments consist of plutons on the western margin of the Neoproterozo- Dirección de Geociencias Básicas ic basement and show wide lithological variation in both igneous (monzodiorites, Grupo de Estudios Geológicos Especiales Calle 75 n.° 79A–51 Triassic quartz monzonites, tonalites, granodiorites, monzogranites, and syenogranites) and Medellín, Colombia metamorphic (migmatites, gneisses, and mylonitic gneisses) rocks. The granites have 4 [email protected] Servicio Geológico Colombiano a metaluminous to peraluminous character and correspond to calc–alkaline to high– Dirección de Geociencias Básicas potassium calc–alkaline series formed in a continental arc environment.
    [Show full text]
  • Tectonostratigraphic Terranes in Colombia: an Update. First Part
    Volume 1 Quaternary Chapter 3 Neogene https://doi.org/10.32685/pub.esp.35.2019.03 Tectonostratigraphic Terranes Published online 14 April 2020 in Colombia: An Update First Part: Continental Terranes Paleogene Jorge Julián RESTREPO1* and Jean–François TOUSSAINT2 1 [email protected] Universidad Nacional de Colombia Sede Medellín GEMMA Research Group Abstract The quite abundant geological information that has been produced in recent Cretaceous years in Colombia, especially in geochronological and geological mapping, necessitates Medellín, Colombia 2 [email protected] updating the mosaic of geological terranes that comprise the Colombian territory. Universidad Nacional de Colombia Several modifications to these characteristics and boundaries are proposed for ter- Medellín, Colombia * Corresponding author ranes such as Chibcha, Tahamí, and Calima. Some small terranes that have been de- Jurassic fined recently, including Anacona, Ebéjico (Quebradagrande), and Pozo (Arquía), are placed within the context of the larger terranes. In addition, some new terranes, in- cluding Yalcón, Bocaná, Aburrá, Kogi, and Tairona, are defined and their characteristics are described. With these new geochronological data, we propose that the metamor- phic Cajamarca Complex be replaced by two new lithodemical units: the Antioquia Triassic Complex, which covers mostly rocks that formed during Permian and Triassic meta- morphism, and the Coello Complex, which comprises metamorphic rocks that formed during Jurassic metamorphism. Future lines of investigation are proposed to solve remaining problems, especially the boundaries of some of the newly defined terranes. Permian Keywords: continental terranes, accretions, displaced terranes, Colombia, Andes. Resumen La abundante cantidad de información geológica que se ha generado en los últimos años en Colombia, en particular geocronológica y cartográfica, implica la necesidad de actualizar el mosaico de terrenos geológicos que constituyen el terri- Carboniferous torio colombiano.
    [Show full text]
  • Cajamarca, Cordillera Central De Colombia)
    vol. 41, n.° 3, septiembre-diciembre de 2019 ISSN impreso: 0120-0283 ISSN en línea: 2145-8553 Influencia de la actividad tectónica y volcánica reciente en la dinámica fluvial del río Anaime (Cajamarca, Cordillera Central de Colombia) Helbert García-Delgado1*, Silvia Machuca1 doi: http://dx.doi.org/10.18273/revbol.v41n3-2019003 Forma de citar: García-Delgado, H., y Machuca, S. (2019). Influencia de la actividad tectónica y volcánica reciente en la dinámica fluvial del río Anaime (Cajamarca, Cordillera Central de Colombia). Boletín de Geología, 41(3), 57-83. doi: 10.18273/revbol.v41n3-2019003. RESUMEN El valle del río Anaime, localizado en la parte central de la Cordillera Central, se encuentra en una zona con influencia tectónica importante por estructuras regionales que hacen parte de los Sistemas de Fallas de Palestina e Ibagué. Además de lo anterior, esta zona ha estado bajo influencia de eventos volcánicos regionales como producto de la actividad reciente durante los últimos 5000 años del Volcán Cerro Machín. En este trabajo se presenta un análisis geomorfológico cuantitativo a partir del uso de diferentes índices geomorfológicos tales como la curva e integral hipsométrica, el índice de forma de la cuenca, el factor de asimetría, la relación ancho-altura del valle, perfiles longitudinales normalizados y el índice de extensión pendiente-relativa con el objetivo de analizar la influencia de la tectónica y la actividad volcánica en la evolución reciente del paisaje en el río Anaime. Los análisis geomorfológicos muestran que la evolución reciente del paisaje a lo largo de la parte alta del valle del río Anaime ha estado controlada por caídas locales en el nivel base inducidas por actividad tectónica reciente de la Falla de Palestina y con menor influencia por la Falla de Ibagué.
    [Show full text]
  • La Colosa Au Porphyry Deposit, Colombia: Mineralization Styles, Structural Controls, and Age Constraints
    BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS Vol. 113 May No. 3 La Colosa Au Porphyry Deposit, Colombia: Mineralization Styles, Structural Controls, and Age Constraints Andrés Naranjo,¹,†,* Johannes Horner,² Rudolf Jahoda,¹ Larryn W. Diamond,3 Adriana Castro,¹ Aura Uribe,¹ Carolina Perez,¹ Hermel Paz,¹ Carlos Mejia,¹ and Jonas Weil² 1 AngloGold Ashanti Colombia, Carrera 19 Sur 162-70, Ibagué, Tolima 050026, Colombia 2 iC Consulenten, Zollhausweg 1, A5101, Salzburg, Austria 3 Institute of Geological Sciences, University of Bern, Baltzerstrasse 3, 3012 Bern, Switzerland Abstract The La Colosa porphyry Au deposit is located on the eastern flank of the Central Cordillera of Colombia, within the Middle Cauca metallogenic belt. The deposit contains more than 800 t (22.37 Moz) Au at grades up to 0.8 g/t and is hosted by a composite porphyry stock of dioritic to tonalitic composition, which was emplaced into Triassic-Cretaceous schists of the Cajamarca Complex in the late Miocene (~8 Ma). The country rocks underwent two ductile deformation events, including development of shear zones, folds, and penetrative foliation, prior to emplacement of the stock. Subsequent brittle deformation reactivated preex- isting N- and NNE-trending structures and formed secondary faults due to a change from right- to left-lateral shear sense on regional faults. This switch in stress orientations is attributed to a new plate configuration in the mid-Miocene. The left-lateral movement along regional faults favored emplacement of intrusive centers in dilational pull-apart zones, including the La Colosa stock within the regional Palestina fault zone. The La Colosa porphyry stock was intruded in three stages, termed early, intermineral, and late, all within a relatively short time interval of ~1.1 m.y.
    [Show full text]
  • Neotectonics of Arc-Continent Collision Manizales, Colombia
    Neotectonics of Arc-Continent Collision Manizales, Colombia Field Trip Guide 80°W 78°W 76°W 74°W 72°W 70°W 12°N Caribbean plate CART 10°N SMBF MONT CHEP 8°N 12Ma BUCM CP 12Ma 11Ma RION 11Ma 10Ma 6°N a 9M MZAL Sandra rift9Ma 10Ma 11Ma BOGO 12Ma 4°N MR South American Nazca plate plate LFS 2°N N 20 mm/yr 0 100 200 km 17-21 January, 2011 A GSA Penrose Meeting 1 The Geological Society of America, Penrose Meeting: Neotectonics of arc-continent collision Manizales, Colombia, January 17-21, 2011 Field guides for day excursions to the Nevado del Ruiz volcano on Tuesday, January 18, and to the Romeral fault system on Thursday, January 20, 2011 Part 1: Map showing routes for both field trips and general field trip information Part 2: Tectonic setting of the field trip areas from sedimentary basins to subducted slabs in the upper mantle (Discussion leaders: Carlos A. Vargas and Paul Mann) Part 3: Field guide to the tectonic setting and stratigraphy of the Nevado del Ruiz volcano (Field trip leader: Carlos Borrero, with assistance from Maria Luisa Monsalve and Carlos A. Vargas) Part 4: Field guide to the Romeral fault system, Colombia: A suture zone between continental and accreted oceanic crust (Field trip leader: Alvaro Nivia, with assistance from Fabio Cediel, Andreas Kammer, Hector Mora, Hans Diederix, and Carlos A. Vargas) 2 Part 1: Map showing routes for both field trips and general field trip information Figure 1 shows the regional setting of Colombia, the southwestern Caribbean and the eastern Pacific Ocean.
    [Show full text]
  • Santa Barbara Property, Colombia
    June, 2019 - Technical Report Santa Barbara Property, Colombia GEOLOGICAL REPORT ON THE SANTA BARBARA PROPERTY Licence IEV-16061C2 San Martin de Loba Municipality Bolivar Department (Colombia) -Prepared for- Malabar Gold Corp. 2001-1177 West Hastings Street Vancouver, British Columbia, V6E 2K3 -Prepared by- T.N.J. Hughes, P. Geo., P. Geol. Antediluvial Consulting Inc. Vancouver, British Columbia, Canada 26th June, 2019 June, 2019 - Geological Report Santa Barbara Property, Colombia GEOLOGICAL REPORT ON THE SANTA BARBARA PROPERTY Table of Contents 1 EXECUTIVE SUMMARY ..................................................................................................................... 1 2. INTRODUCTION & TERMS OF REFERENCE ........................................................................... 3 3. RELIANCE ON OTHER EXPERTS .................................................................................................. 6 4. PROPERTY DESCRIPTION AND LOCATION ............................................................................ 7 4.2 Legal Framework ........................................................................................................................................... 11 5. ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY ..................................................................................................................................... 23 6. HISTORY ..............................................................................................................................................
    [Show full text]
  • Tectonic Assembly of the Northern Andean Block, in C
    Cediel, F., R. P. Shaw, and C. Ca´ceres, 2003, Tectonic assembly of the Northern Andean Block, in C. Bartolini, R. T. Buffler, and J. Blickwede, eds., The Circum-Gulf of Mexico and the Caribbean: Hydrocarbon habitats, basin formation, and plate tectonics: AAPG Memoir 79, 37 p. 815–848. Tectonic Assembly of the Northern Andean Block Fabio Cediel Geotec Ltda., Bogota´, Colombia Robert P. Shaw Geotec Ltda., Bogota´, Colombia Carlos Ca´ceres Geotec Ltda., Bogota´, Colombia ABSTRACT ased primarily on geologic field observations as recorded by numerous geoscientists over the last three decades, backed by more recent geo- B chemical, seismic, gravity, magnetic, tomographic, and satellite-based techniques, an integrated synthesis and interpretation of the tectonic assembly of the entire Northern Andean Block (the Andes of Ecuador, Colombia, and Ven- ezuela) is presented. Tectonic reconstruction is based on the identification and characterization of more than 30 distinct lithotectonic and morphostructural units (including terranes, terrane assemblages, physiographic domains, etc.) and their bounding suture and fault systems, which, based on geologic, geophysical, and dynamo-tectonic considerations, define four distinct tectonic realms representing the entire Northern Andean region. These include the Guiana Shield Realm (GSR), the Maracaibo subplate Realm (MSP), the Central Continental subplate Realm (CCSP), and the Western Tectonic Realm (WTR). The GSR pro- vided the backstop for the progressive, accretionary continental growth of northwestern South America in the middle–late Proterozoic, in the middle Paleozoic, and finally during the Mesozoic-Cenozoic Northern Andean orogeny. Middle Cretaceous through Miocene time slices illustrate how, beginning in the Aptian, the sequential dextral-oblique accretion of the allochthonous oceanic WTR along the Pacific margin acted simultaneously with the northwest migration of the MSP (a detached segment of the Guiana Shield) into and over the Caribbean plate, exerting enormous transpression upon the CCSP trapped between them.
    [Show full text]