The Cretaceous Alkaline Magmatism in Northeast Iberia: Igneus Processes and Geodynamic Implications
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2013 147 Teresa Ubide Garralda The Cretaceous alkaline magmatism in northeast Iberia: igneus processes and geodynamic implications Departamento Ciencias de la Tierra Director/es Arranz Yagüe, Enrique Lago San José, Marceliano Tesis Doctoral Autor Director/es UNIVERSIDAD DE ZARAGOZA Repositorio de la Universidad de Zaragoza – Zaguan http://zaguan.unizar.es Departamento Director/es Tesis Doctoral THE CRETACEOUS ALKALINE MAGMATISM IN NORTHEAST IBERIA: IGNEUS PROCESSES AND GEODYNAMIC IMPLICATIONS Autor Teresa Ubide Garralda Director/es Arranz Yagüe, Enrique Lago San José, Marceliano UNIVERSIDAD DE ZARAGOZA Ciencias de la Tierra 2013 Repositorio de la Universidad de Zaragoza – Zaguan http://zaguan.unizar.es Departamento Director/es Tesis Doctoral Autor Director/es UNIVERSIDAD DE ZARAGOZA Repositorio de la Universidad de Zaragoza – Zaguan http://zaguan.unizar.es THE CRETACEOUS ALKALINE MAGMATISM IN NORTHEAST IBERIA. IGNEOUS PROCESSES AND GEODYNAMIC IMPLICATIONS TERESA UBIDE GARRALDA PhD THESIS 2013 UNIVERSIDAD DE ZARAGOZA FACULTAD DE CIENCIAS DEPARTAMENTO DE CIENCIAS DE LA TIERRA GRUPO DE INVESTIGACIÓN GEOTRANSFER Supervisors Dr. Enrique Arranz Yagüe Dr. Marceliano Lago San José A mis padres Contents Agradecimientos Resumen Summary Chapter 1. Introduction ........................................................................................... 1 1.1. Interest ....................................................................................................................................... 3 1.2. Objectives ................................................................................................................................... 7 1.3. Outline ........................................................................................................................................ 8 Chapter 2. Materials and Methods ........................................................................ 11 2.1. Samples .....................................................................................................................................13 2.2. Methodology .............................................................................................................................13 2.2.1. Field work .......................................................................................................................13 2.2.2. Laboratory work .............................................................................................................13 2.2.3. Data treatment ...............................................................................................................18 2.2.4. Presentation of results ...................................................................................................18 Chapter 3. Age of the Cretaceous alkaline magmatism in northeast Iberia: implications for the Alpine cycle in the Pyrenees .................................................. 21 3.1. Introduction ...............................................................................................................................23 3.2. The Cretaceous magmatism in northeast Iberia: geological context, characterisation and previous dating results ..............................................................................................................24 3.2.1. Pyrenees .........................................................................................................................24 3.2.2. Catalonian Coastal Ranges ..............................................................................................26 3.3. Samples and methods ...............................................................................................................27 3.3.1. Location and description of the samples ........................................................................27 3.3.2. 40Ar/39Ar methodology ....................................................................................................30 3.4. Results .......................................................................................................................................32 3.5. Discussion ..................................................................................................................................36 3.5.1. The Triassic-Jurassic rifting in the Central Pyrenees ......................................................36 3.5.2. The Cretaceous opening of the Bay of Biscay and rotation of Iberia .............................37 3.5.3. The onset of Alpine compression in the Late Cretaceous ..............................................43 3.6. Conclusions ................................................................................................................................45 3.7. Appendix ....................................................................................................................................47 Chapter 4. Petrogenesis of the Cretaceous alkaline magmatism in northeast Iberia: new insights into the evolution of the mantle source ................................ 51 4.1. Introduction .............................................................................................................................. 53 4.2. Geological context, igneous typologies and previous studies .................................................. 53 4.3. Samples and methods .............................................................................................................. 55 4.4. Petrology .................................................................................................................................. 62 4.5. Geochemistry ........................................................................................................................... 65 4.5.1. Classification and affinity ............................................................................................... 65 4.5.2. Major and trace element variations .............................................................................. 67 4.5.3. Sr-Nd-Pb isotope composition ....................................................................................... 71 4.6. Discussion ................................................................................................................................. 73 4.6.1. Source enrichment and mantle heterogeneity ............................................................. 73 4.6.2. Evolution of the mantle source since the beginning of the Alpine cycle ...................... 78 4.7. Conclusions ............................................................................................................................... 83 Chapter 5. The Cretaceous lamprophyre suite in the Catalonian Coastal Ranges: complex antecryst populations and their effect on whole rock compositions ...... 85 5.1. Introduction .............................................................................................................................. 87 5.2. Geological context .................................................................................................................... 88 5.3. Field appearance of the lamprophyres .................................................................................... 88 5.4. Samples and methods .............................................................................................................. 95 5.5. Petrography .............................................................................................................................. 97 5.5.1. The macrocryst assemblage .......................................................................................... 97 5.5.2. The groundmass .......................................................................................................... 100 5.6. Mineral chemistry ................................................................................................................... 101 5.6.1. Major element composition ........................................................................................ 101 5.6.2. Trace element composition ......................................................................................... 111 5.7. Whole rock chemistry ............................................................................................................. 113 5.7.1. Major element composition ........................................................................................ 113 5.7.2. Trace element composition ......................................................................................... 116 5.8. Discussion ............................................................................................................................... 117 5.8.1. Origin of mineral compositional variations ................................................................. 117 5.8.2. Origin of whole rock compositional variations ............................................................ 123 5.8.3. Reconstruction of the magmatic plumbing system ..................................................... 126 5.9. Conclusions ............................................................................................................................. 129 Chapter 6. The influence of crystal settling on the compositional zoning of a thin lamprophyre sill: a multi-method approach ................................................. 131 6.1. Introduction ............................................................................................................................ 131 6.2. Field observations