The igneous rocks of Greece The anatomy of an orogen by Georgia Pe-Piper David J.W. Piper With 288 figures and 11 tables 2002 GEBRUDER BORNTRAEGER • BERLIN • STUTTGART Contents Preface V Abbreviations and acronyms XVI 1 Introduction 1 1.1 Igneous rocks within the Hellenide orogen 1 1.2 Organization of the book 3 1.2.1 Introduction 3 1.2.2 Rock and mineral nomenclature 3 1.3 Outline of the geology of Greece 6 1.3.1 Introduction 6 1.3.2 A brief history of geological studies in Greece 6 1.3.3 Terranes of the Hellenides 8 1.3.4 Pre-Mesozoic continental basement 10 1.3.5 Tectono-stratigraphy of the Hellenides 11 1.3.6 Mesozoic rifting and sedimentation 11 1.3.7 The ophiolites 14 1.3.8 Alpine orogenesis 14 1.3.9 Neogene extension and block rotation 15 1.3.10 Cenozoic igneous activity 16 1.4 The present geophysical fields 19 1.5 Plate tectonic evolution of Greece 21 2 Late Paleozoic plutonism and volcanism 25 2.1 Introduction: the Hercynian basement of Greece 25 2.2 Plutons in the Pelagonian zone of Thessaly and western Macedonia: type example 26 2.2.1 Regional structural setting 26 2.2.2 Geology of the Verdikoussa pluton 28 2.2.3 Geology of other plutons of the Pelagonian zone 28 2.3 Probable Hercynian plutonism in northeastern Greece 31 2.3.1 Vardar zone 31 2.3.2 Serbo-Macedonian and Rhodope zones 32 2.3.3 Basement rocks of western Anatolia 32 2.4 Hercynian basement rocks in southern Greece 33 2.4.1 Cyclades islands 33 VIII Contents 2.4.2 Crete, Dodecanese and the Peloponnese 34 2.4.3 Attiki, Othris, Evia and Chios 35 2.5 Geology of volcanic rocks of Karakaya suture zone 35 2.5.1 Introduction 35 2.5.2 Geological setting of Chios 36 2.5.3 Geological setting of Lesbos 37 2.5.4 The possible extension of the Karakaya suture to Greece 38 2.6 Petrography and geochemistry 38 2.6.1 Petrography of the granitoid rocks 38 2.6.2 Petrography of the mafic plutonic rocks 42 2.6.3 Geochemistry of the granitoid rocks and associated mafic rocks 42 2.6.4 Geochemistry of the Hercynian amphibolites 49 2.6.5 Geochemistry of the Paleozoic volcanic rocks of Chios 49 2.7 Synthesis of the regional setting of Carboniferous plutons 51 3 Triassic rifting and volcanism 57 3.1 General geologic history of the early Mesozoic of Greece 57 3.1.1 Introduction: the creation ofNeotethys 57 3.1.2 Plate-tectonic interpretation ofTriassic rifting 58 3.1.3 Permian-Triassic rifting in Greece 60 3.2 Othris and north Evia: a type example 61 3.2.1 Introduction 61 3.2.2 Geologic setting of the early to mid-Triassic early-rifting volcanic rocks.... 63 3.2.3 Geologic setting of the Carnian volcanic rocks of Othris 64 3.2.4 Geologic setting of Plate Triassic - PJurassic ocean-floor of Othris and Evia 65 3.2.5 Petrography and geochemistry of the early to mid-Triassic alkaline volcanic rocks :: 65 3.2.6 Petrography and geochemistry of mid-to late Triassic subalkaline volcanic rocks 67 3.2.7 Petrography and geochemistry of the late Triassic — early Jurassic ocean floor rocks ; 71 3.2.8 Regional implications of the Othris-Evia transect 71 3.3 Geology ofTriassic volcanic rocks of Apulia on the margin of the Pindos ocean 73 3.3.1 Phyllite-Quartzite Unit 73 3.3.2 Western margin of the Pindos zone 76 3.3.3 Pindos zone of Crete and the south Aegean islands 77 3.3.4 Triassic volcanic rocks within melanges 77 3.3.5 Kerassies — Milea ophiolite zone 78 3.3.6 Parnassos zone 78 3.4 ?Triassic meta-igneous rocks of the Cyclades, south Evia and Thessaly 79 3.4.1 Introduction 79 3.4.2 Basal Unit of the Cyclades: volcanic rocks 79 3.4.3 Basal Unit of the Cyclades: granites 80 3.4.4 Intermediate Unit of the Cyclades 80 Contents IX 3.4.5 The Styra-Ochi unit of southern Evia 81 3.4.6 The blueschist units ofThessaly 82 3.5 Geology of Triassic volcanic rocks of Pelagonia 82 3.5.1 The Pelagonian nappes of mainland Greece 82 3.5.2 Upper Unit of the Cyclades and Pelagonian nappes of the eastern Aegean islands 83 3.6 Geology ofTriassic volcanic rocks of the Vardar and Serbo-Macedonian zones 84 3.6.1 Introduction 84 3.6.2 Circum-Rhodope belt 85 3.6.3 Summary 88 3.7 Petrography and geochemistry 88 3.7.1 Introduction 88 3.7.2 Subalkaline basaltic andesite and related rocks 88 3.7.3 Basalt and andesite of shoshonitic or calc-alkaline affinity 93 3.7.4 Alkaline basalt 94 3.7.5 MORB-related rocks 95 3.7.6 Subalkaline rocks with boninitic affinities 96 3.7.7 Rhyolite 97 3.8 Regional synthesis 99 3.8.1 Stratigraphic and paleogeographic distribution of volcanic rocks 99 3.8.2 The relationship ofTriassic volcanism to rifting and mantle plumes 100 3.8.3 The role of subduction and back-arc spreading in the genesis of Triassic volcanic rocks 101 4 Jurassic Pindos ocean basin: ophiolites and melanges 104 4.1 Introduction: the western ophiolite belt of Greece 104 4.2 Type example: the Vourinds and Pindos ophiolites 106 4.2.1 Geology of the Vburinos ophiolite 106 4.2.2 Geology of the Pindos ophiolite 109 4.2.3 Petrography and geochemistry of the Vourinos and Pindos ophiolites 112 4.2.4 The significance of sub-ophiolitic melange 117 4.2.5 Emplacement of the Vourinos and Pindos ophiolites 119 4.3 The western Jurassic ophiolite sequences and related rocks of the Pelagonian zone 123 4.3.1 Introduction 123 4.3.2 Ophiolites of northwestern Thessaly and western Macedonia 123 4.3.3 Ophiolites of Othris 124 4.3.4 Ophiolites of Evia and Pelion 126 4.3.5 Ophiolites of Beotia and Attiki 126 4.3.6 Ophiolites of Argolis 128 4.3.7 Melanges beneath the western ophiolite belt 129 4.3.8 The record of volcanism in the foreland basin created by the obducting ophiolites 130 4.3.9 Evidence for ophiolites in detrital conglomerates of the external Hellenides 131 X Contents 4.3.10 Tectonic slices in die Pindos basin of the Peloponnese 131 4.3.11 Clay-mineral and manganese evidence for volcanic activity 132 4.3.12 Ultramafic and mafic rocks of the lower nappe of the Phyllite-Quartzite unit 132 4.4 Meta-ophiolites in the Intermediate Unit of the Attico-Cycladic complex and possible correlatives inThessaly 133 4.4.1 Introduction 133 4.4.2 Cyclades 133 4.4.3 Blueschist unit ofThessaly 135 4.5 The "Ophiolite nappe" of Crete, the south Aegean islands, and the upper unit of the Cyclades 135 4.5.1 Introduction 135 4.5.2 Crete and Gavdos 135 4.5.3 Karpathos and Rhodos 136 4.5.4 Ophiolites of the Upper Unit of the Cyclades 136 4.6 Petrography and geochemistry of die western ophiolite belt 138 4.6.1 Volcanic and dyke rocks 138 4.6.2 Plutonic rocks 141 4.6.3 Ultramafic rocks 143 4.6.4 Chromite 144 4.6.5 Hydrothermal mineralization 145 4.7 Synthesis: distribution and origin of Jurassic oceanic igneous rocks 146 4.7.1 Oceanic environments revealed by geochemical studies 146 4.7.2 What oceans did the ophiolites come from? 147 5 Mesozoic ocean crust of northeast Greece 151 5.1 Tectonic and stratigraphic setting of northeast Greece 151 5.2 Mesozoic igneous rocks of the Vardar zone .... 154 5-2.1 Almopias subzone: geological summary 154 5.2.2 Ophiolites of the eastern Almopias subzone 158 5.2.3 Dismembered ophiolites of the central Almopias subzone 159 5-2.4 Ophiolites of the western Almopias subzone 160 5.2.5 Eastern Thessaly and Pelion 160 5.2.6 Eohellenic unit of the islands of the northwest Aegean Sea 163 5.2.7 Palkon subzone 165 5.2.8 Peonias subzone: overview 167 5-2.9 Guevgueli ophiolites 169 5.2.10 Granites of the Peonias subzone 171 5.2.11 Stip-Axios massif 171 5.2.12 Thessaloniki ophiolites 171 5.2.13 Oreokastro ophiolite 172 5.2.14 Aspro Vrissi Formation 173 5.2.15 Chortiatis magmatic suite of nordiern Chalkidiki 173 5.2.16 Chortiatis magmatic suite of Sithonia 174 5.2.17 Sithonia ophiolitic rift complex 175 5.2.18 The circum-Rhodope belt in Samothraki 178 Contents XI 5.2.19 The circum-Rhodope belt of southeastern Thrace 180 5.2.20 Ophiolites of the northeast Aegean 183 5.3 Mesozoic igneous rocks of the Rhodope and Serbo-Macedonian zones... 185 5.3.1 Outline of the geology of the Rhodope and Serbo-Macedonian zones .... 185 5.3.2 Geology of meta-igneous rocks of the Rhodope zone 189 5.3.3 Geology of meta-ophiolites and amphibolites of the Serbo-Macedonian zone 190 5.3.4 Granites of the Serbo-Macedonian zone 192 5.4 Petrography and geochemistry of Mesozoic igneous rocks of northeastern Greece 193 5.4.1 Ophiolitic rocks of the Almopias subzone 193 5.4.2 Ophiolitic rocks of the eastern Peonias subzone 196 5.4.3 Guevgueli ophiolites 199 5.4.4 Sithonia ophiolites 201 5.4.5 Ophiolitic rocks of Samothraki and Thrace 204 5.4.6 Ophiolitic rocks of the Rhodope and Serbo-Macedonian zones 206 5.4.7 Ophiolitic rocks of Lesbos 207 5.4.8 Subduction-related volcanism of the Pa'ikon subzone 210 5.4.9 Chortiatis suite 210 5.4.10 Jurassic dykes and granites of the Vardar zone 212 5.4.11 Older granites of the Serbo-Macedonian zone 213 5.5 Regional synthesis 216 5.5.1 Regional tectonic framework 216 5.5.2 The ophiolites of the Vardar zone and circum-Rhodope belt 218 5.5.3 Tectonic evolution of the Serbo-Macedonian and Rhodope zones 222 5.5.4 A plate tectonic model 223 6 Cretaceous ophiolites and subduction in central and south Greece 226 6.1 Late Cretaceous ophiolitic rocks 226 6.1.1 Late Cretaceous oceanic crust in central Evia 226 6.1.2 Possible latest Cretaceous oceanic crust in the Sporades, Pelion, Skyros and Macedonia ; 226 6.1.3 The Ermioni Complex of Argolis 228 6.1.4 Cretaceous oceanic crust in the south Aegean islands 228 6.1.5 Stratigraphic distribution of manganiferous sedimentary rocks in the Pindos basin 229 6.1.6 Petrography and geochemistry of the ophiolitic rocks 229 6.2 Cretaceous subduction/accretion complexes 231 6.2.1 Crete 231 6.2.2 Cyclades 233 6.2.3