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Serpentinization and Metasomatism

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Serpentinization and Metasomatism National and Kapodistrian University of Athens Faculty of Geology and Geoenvironment Department of Mineralogy and Petrology Serpentinization and Metasomatism Constraints to their relationship through mineralogical, petrological and geochemical study of rodingitized dykes intruded ultramafic rocks of Kimi district, Evia, Greece Christos Karkalis MSc Thesis Supervisor Prof. Andreas Magganas 2018 Three-Member Committee Professor Andreas Magganas (Supervisor) Assistant Professor Panagiotis Pomonis Professor Konstantinos Kyriakopoulos 1 Contents Contents ................................................................................................................................................................ 1 Abstract ................................................................................................................................................................. 6 Περίληψη .............................................................................................................................................................. 7 Acknowledgments ............................................................................................................................................ 9 1 Introduction ............................................................................................................................................ 10 2 Serpentinization and Metasomatism – State of the Art ......................................................... 12 2.1 Description of metasomatism and metamorphism ....................................................... 12 2.2 Metasomatic features ................................................................................................................ 12 2.3 Metasomatic processes ............................................................................................................. 12 2.4 Metasomatism associated with ultramafic rocks ........................................................... 12 2.5 Serpentinization .......................................................................................................................... 13 2.5.1 Geotectonic environments of serpentinization ..................................................... 13 2.5.1.1 Abyssal or oceanic serpentinites ............................................................................ 14 2.5.1.2 Mantle wedge serpentinites ..................................................................................... 14 2.5.1.3 Subducted serpentinites ............................................................................................ 15 2.5.2 Serpentinite Subduction Channel ............................................................................... 15 2.5.3 The chemical process of serpentinization ............................................................... 15 2.5.4 Serpentinite deformation ............................................................................................... 16 2.6 Carbonization of ultramafic rocks ........................................................................................ 16 2.6.1 Magnesites - Ophimagnesites ....................................................................................... 16 2.6.2 Ophicalcites .......................................................................................................................... 18 2.6.3 Listwanite ............................................................................................................................. 19 2.6.4 Ophicalcites Listwanites and Magnesites in Evia ................................................. 20 2.7 Blackwall alteration and steatitization .............................................................................. 21 2.8 Diopsiditization ............................................................................................................................ 22 2.9 Rodingitization ............................................................................................................................. 22 2.9.1 Rodingite definition .......................................................................................................... 22 2.9.2 Chemistry of rodingitization & rodingites’ formation ........................................ 23 2.9.3 Physicochemical Conditions of rodingitization ..................................................... 24 2.9.4 Rodingitization and serpentinization ........................................................................ 24 2.9.5 Mineralogy and mineral chemistry of rodingites - Stages of rodingitization 25 2.9.6 Derodingitization and Metarodingites ...................................................................... 27 2.9.7 Rodingite occurrences in Greece ................................................................................. 28 2 2.9.7.1 Kimi rodingites .............................................................................................................. 30 3 Geological Background ....................................................................................................................... 32 3.1 Geological division of the Hellenides .................................................................................. 32 3.2 Pelagonian Zone ........................................................................................................................... 33 3.3 Vardar Zone ................................................................................................................................... 34 3.4 Attico-Cycladic Complex ........................................................................................................... 34 3.5 Evia geological setting ............................................................................................................... 34 3.6 Southern Evia ................................................................................................................................ 35 3.7 Central-Northern Evia and Kimi Geological Setting ...................................................... 35 3.8 The Kimi flysch ............................................................................................................................ 40 4 Field Work ................................................................................................................................................ 42 4.1 Sedimentary Rocks of Flysch .................................................................................................. 43 4.2 Ultramafic Rocks .......................................................................................................................... 44 4.1 Ophicalcites .................................................................................................................................... 47 4.2 Rodingites ....................................................................................................................................... 48 4.3 Talc Schists ..................................................................................................................................... 55 5 Analytical Methods ............................................................................................................................... 56 6 Petrography ............................................................................................................................................. 59 6.1 Rodingites ....................................................................................................................................... 59 6.1.1 Group-I Non-Carbonated Rodingites ......................................................................... 60 6.1.1.1 Rodingite Core Zones .................................................................................................. 60 6.1.1.2 Rodingite Marginal Zone ............................................................................................ 62 6.1.1.3 Rodingite Transitional Zone ..................................................................................... 63 6.1.2 Group-II Calcite bearing rodingites ............................................................................ 65 6.1.2.1 Rodingite Core Zones .................................................................................................. 65 6.1.2.2 Rodingite Marginal Zone ............................................................................................ 66 6.1.2.3 Rodingite Transitional Zone ..................................................................................... 68 6.2 Ultramafics ..................................................................................................................................... 72 6.2.1 Serpentinized Peridotites ............................................................................................... 72 6.2.2 Metasomatized Serpentinites ....................................................................................... 74 6.2.3 Chloritites ............................................................................................................................. 75 7 Mineral Chemistry ................................................................................................................................ 77 7.1 Vesuvianite ..................................................................................................................................... 77 7.2 Garnet and Hydrogarnet..........................................................................................................
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