CENOZOIC VOLCANISM IN THE TYRRHENIAN SEA REGION
CONTENTS MAGMATISM IN THE TYRRHENIAN SEA REGION: AN INTRODUCTORY OVERVIEW INTRODUCTION GEOCHRONOLOGY AND PETROLOGY REGIONAL DISTRIBUTION OF MAGMA TYPES REGIONAL VARIATION OF TRACE ELEMENT AND SR-ND–PB-O ISOTOPIC COMPOSITIONS MAGMATIC PROVINCES IN THE TYRRHENIAN SEA REGION PETROGENESIS AND GEODYNAMIC SETTING: A PRELIMINARY PERSPECTIVE SUMMARY AND CONCLUSIONS REFERENCES THE TUSCANY PROVINCE REGIONAL GEOLOGY COMPOSITION AND CLASSIFICATION OF TUSCANY MAGMATISM SILICIC MAGMATISM EFFUSIVE ROCKS PLUTONIC ROCKS MAFIC MAGMATISM PETROGENESIS OF THE TUSCANY MAGMATIC PROVINCE ORIGIN OF SILICIC MAGMAS ORIGIN OF MAFIC MAGMAS GEODYNAMIC IMPLICATIONS THE INTRA-APENNINE PROVINCE COMPOSITIONAL CHARACTERISTICS OF INTRA-APENNINE MAGMATISM SAN VENANZO CUPAELLO POLINO ORICOLA INTRA-APENNINE PYROCLASTIC DEPOSITS COLLE FABBRI PETROGENESIS OF THE INTRA-APENNINE PROVINCE KAMAFUGITIC ROCKS CARBONATE-RICH ROCKS THE ROMAN PROVINCE VULSINI DISTRICT VOLCANOLOGY AND STRATIGRAPHY PETROGRAPHY AND MINERAL CHEMISTRY PETROLOGY AND GEOCHEMISTRY EVOLUTION OF VULSINI MAGMAS VICO VOLCANO EVOLUTION OF VICO MAGMAS SABATINI DISTRICT EVOLUTION OF SABATINI MAGMAS COLLI ALBANI (ALBAN HILLS) EVOLUTION OF COLLI ALBANI MAGMAS PETROGENESIS OF THE ROMAN PROVINCE MAGMA EVOLUTION PROCESSES GENESIS OF PRIMARY MAGMAS AGE OF MANTLE METASOMATISM AND GEODYNAMIC IMPLICATIONS PHYSICAL MODELS OF MANTLE METASOMATISM THE ERNICI-ROCCAMONFINA PROVINCE ERNICI EVOLUTION OF ERNICI MAGMAS ROCCAMONFINA EVOLUTION OF ROCCAMONFINA MAGMAS PETROGENESIS OF THE ERNICI-ROCCAMONFINA PROVINCE MANTLE METASOMATISM AND GEODYNAMIC IMPLICATIONS THE PONTINE ISLANDS WESTERN PONTINE ISLANDS: PONZA, LA BOTTE, PALMAROLA AND ZANNONE VENTOTENE AND SANTO STEFANO PETROGENESIS AND GEODYNAMIC SIGNIFICANCE OF PONTINE ISLANDS THE CAMPANIA PROVINCE SOMMA-VESUVIO EVOLUTION OF SOMMA-VESUVIO MAGMAS CAMPI FLEGREI (PHLEGRAEAN FIELDS) EVOLUTION OF CAMPI FLEGREI MAGMAS ISCHIA ISLAND EVOLUTION OF ISCHIA MAGMAS PROCIDA AND VIVARA EVOLUTION OF PROCIDA AND VIVARA MAGMAS BURIED VOLCANISM BENEATH THE CAMPANIAN PLAIN PETROGENESIS OF CAMPANIA MAGMAS GEODYNAMIC SIGNIFICANCE THE APULIAN PROVINCE (MOUNT VULTURE) MOUNT VULTURE PETROGENESIS OF VULTURE MAGMAS GEODYNAMIC SIGNIFICANCE OF MOUNT VULTURE THE AEOLIAN ARC ALICUDI MAGMA EVOLUTION AT ALICUDI FILICUDI MAGMA EVOLUTION AT FILICUDI SALINA MAGMA EVOLUTION AT SALINA LIPARI MAGMA EVOLUTION AT LIPARI VULCANO MAGMA EVOLUTION AT VULCANO PANAREA MAGMA EVOLUTION AT PANAREA STROMBOLI MAGMA EVOLUTION AT STROMBOLI AEOLIAN SEAMOUNTS PETROGENESIS OF THE AEOLIAN ARC MAGMAS ROLE OF MAGMA-EVOLUTION PROCESSES THE SICILY PROVINCE ETNA EVOLUTION OF ETNA MAGMAS AND IMPLICATIONS FOR THE PLUMBING SYSTEM IBLEI VOLCANOLOGY, STRATIGRAPHY, AND PETROGRAPHY EVOLUTION OF IBLEAN MAGMAS PANTELLERIA EVOLUTION OF PANTELLERIA MAGMAS LINOSA EVOLUTION OF LINOSA MAGMAS SICILY CHANNEL SEAMOUNTS USTICA EVOLUTION OF USTICA MAGMAS PETROGENESIS OF THE SICILY PROVINCE 10 10 GEODYNAMIC SIGNIFICANCE 10 11 SUMMARY AND CONCLUSIONS SARDINIA OLIGO-MIOCENE OROGENIC VOLCANIC STAGE PETROGENESIS OF OLIGO-MIOCENE OROGENIC MAGMAS MIOCENE-QUATERNARY ANOROGENIC VOLCANISM PETROGENESIS OF MIOCENE-QUATERNARY ANOROGENIC MAGMATISM GEODYNAMIC SETTING OF OROGENIC AND ANOROGENIC MAGMAS SOUTHERN TYRRHENIAN SEA GEOLOGICAL SETTING IGNEOUS ACTIVITY MORB-TYPE ROCKS OIB-TYPE ROCKS ARC-TYPE ROCKS PETROGENESIS OF THE TYRRHENIAN SEA MAGMATISM GEODYNAMIC SETTING MAGMATISM AND GEODYNAMICS IN THE TYRRHENIAN SEA REGION COMPOSITIONAL AND STRUCTURAL CHARACTERISTICS OF VOLCANISM IN THE TYRRHENIAN SEA REGION GEODYNAMIC EVOLUTION OF THE TYRRHENIAN SEA REGION: A SHORT SUMMARY RELATIONSHIP BETWEEN PETROGENESIS AND GEODYNAMICS PLUME-RELATED HYPOTHESES PASSIVE-RIFTING-RELATED HYPOTHESES SUBDUCTION-RELATED HYPOTHESES CONCLUSIONS MAGMATISM IN THE TYRRHENIAN SEA REGION: AN INTRODUCTORY OVERVIEW ABSTRACT CENOZOIC MAGMATISM IN THE TYRRHENIAN SEA REGION EXHIBITS A WIDE RANGE OF MAJOR, TRACE ELEMENT, AND RADIOGENIC ISOTOPE CHARACTERISTICS BASED ON PETROLOGICAL AND TRACE ELEMENT SIGNATURES, ESPECIALLY LILE/HFSE RATIOS OF MA?C ROCKS, TWO MAIN FAMILIES OF MAGMAS ARE RECOGNISED RESPECTIVELY SHOWING ARC-TYPE (OROGENIC) AND INTRAPLATE (ANOROGENIC) COMPOSITIONAL FEATURES OROGENIC MAGMAS HAVE CALCALKALINE, SHOSHONITIC AND POTASSIC ALKALINE AF?NITIES, AND ARE SPREAD OVER THE ENTIRE TYRRHENIAN REGION BECOMING YOUNGER EASTWARD, FROM THE OLIGO-MIOCENE VOLCANIC BELT OF SARDINIA TO THE YOUNG TO ACTIVE CALCALKALINE TO POTASSIC ALKALINE VOLCANOES OF THE ITALIAN PENINSULA AND THE SOUTHEASTERN TYRRHENIAN SEA LARGE VOLUMES OF QUATERNARY POTASSIC AND ULTRAPOTASSIC ROCKS IN CENTRAL ITALY REPRESENT THE MOST IMPORTANT MAGMA TYPES OF YOUNG OROGENIC ACTIVITY ANOROGENIC ROCKS INCLUDE THOLEIITES TO NA-ALKALINE COMPOSITIONS AND OCCUR IN SARDINIA, IN THE TYRRHENIAN SEA BASIN AND SICILY NO CLEAR AGE POLARITY IS OBSERVED FOR ANOROGENIC ROCKS AREAL DISTRIBUTION, AGES, AND MAJOR, TRACE ELEMENT AND RADIOGENIC ISOTOPE COMPOSITIONS ALLOW RECOGNISING SEVERAL DISTINCT VOLCANIC PROVINCES EXCEPT FOR A FEW RHYOLITES AND GRANITOID ROCKS FROM TUSCANY, THE BULK OF MAGMAS IS OF MANTLE ORIGIN, TESTIFYING TO EXTREMELY HETEROGENEOUS UPPER MANTLE SOURCES GEOCHRONOLOGICAL, PETRO- LOGICAL AND ISOTOPIC DATA SUGGEST THAT MULTIPLE METASOMATIC EVENTS OVER COMPOSITIONALLY VARIABLE PRE-METASOMATIC MANTLE ROCKS ARE RESPONSIBLE FOR THIS HETEROGENEITY KEYWORDS TYRRHENIAN SEA MAGMATIC PROVINCES OROGENIC MAGMATISM ANOROGENIC MAGMATISM MANTLE METASOMATISM APENNINES ALPS ITALY GEODYNAMICS TO 0 3 MA, AND GENERALLY YOUNG TOWARDS THE EAST, FROM THE TUSCAN ARCHIPELAGO TO THE MAINLAND THE AGE OF THIS MAGMATISM EXTENDS TO ABOUT TABLE 1 1 PETROLOGICAL CHARACTERISTICS AND AGES OF CENOZOIC VOLCANIC PROVINCES IN THE TYRRHENIAN SEA REGION MAGMATIC PROVINCE MAIN MAGMATIC CENTERS AND AGES (IN MA) PETROLOGY AND GEOCHEMISTRY SARDINIA OLIGO-MIOCENE (33– 15 MA; SINGLE DATING AT 38 MA) BOSA-LOGUDORO DISTRICT (38–15), ARCUENTU (*30–17), SARROCH (*24–22), SULCIS (*28–15) VOLCANISM EXTENDS TO OFFSHORE WESTERN COAST OF CORSICA, TO THE LIGURIAN SEA (20–7 MA WITH A SINGLE DATING AT 43 MA), AND PROVENCE (33–7 MA) - DISSECTED STRATOVOLCANOES, IGNIMBRITE SHEETS, SUBVOLCANIC BODIES, ETC FORMED OF DOMINANT CALCALKALINE BASALT TO RHYOLITE AND A FEW THOLEIITIC, SHOSHONITIC AND COMENDITIC ROCKS VARIABLE ISOTOPE SIGNATURES (E G 87SR/86SR * 0 704–0 710), MOSTLY RESULTING FROM CRUSTAL ASSIMILATION HIGH LILE/HFSE RATIOS, TYPICAL OF SUBDUCTION RELATED MAGMAS, WITH A VERY FEW OCCURRENCES IN THE LIGURIAN SEA AND PROVENCE, SOUTHEASTERN FRANCE, SHOWING INTRAPLATE-TYPE TRACE ELEMENT SIGNATURES TUSCANY (*14 TO 0 3 MA) ACID INTRUSIONS: ELBA (8 5–6 5), MONTECRISTO (7 1), GIGLIO (5), CAMPIGLIA-GAVORRANO (5– 4 3), VERCELLI SEAMOUNT (7 2) HIDDEN INTRUSIONS IN THE LARDERELLO AREA (<5) ACID VOLCANOES: SAN VINCENZO (4 5), ROCCASTRADA (2 5), AMIATA (0 3), OLDER CIMINI (1 3), TOLFA-MANZIANA-CERITE (3 5) MA?C CENTRES: SISCO (14 5), CAPRAIA (7 6– 4 6), EASTERN ELBA (5 8), CAMPIGLIA (4 3), ORCIATICO AND MONTECATINI (4 1), RADICOFANI (1 3), YOUNGER CIMINI (1 3–0 9), TORRE AL?NA (0 8) - ACID ROCKS: PERALUMINOUS TO METALUMINOUS MONZOGRANITE, GRANODIORITE, GRANITES, APLITES, PEGMATITES (ELBA, MONTECRISTO, GIGLIO, ETC ), LAVA ?OWS AND DOMES (E G SAN VINCENZO, ROCCASTRADA), AND A FEW IGNIMBRITES (CIMINI AND TOLFA) CRUSTAL-TYPE GEOCHEMICAL AND RADIOGENIC ISOTOPE SIGNATURES SUGGESTING CRUSTAL ANATEXIS PLUS MIXING WITH MA?C-INTERMEDIATE MELTS - MA?C-INTERMEDIATE ROCKS: MONOGENETIC EXTRUSIVE AND SUBVOLCANIC BODIES SOMETIMES CONTAINING MANTLE XENOLITHS, STRATOVOLCANO (CAPRAIA), MA?C ENCLAVES IN SILICIC ROCKS, SHOWING CALCALKALINE TO ULTRAPOTASSIC (LAMPROITE) COMPOSITIONS HIGH MG#, NI AND CR, INDICATING A MANTLE ORIGIN, COUPLED WITH CRUSTAL-LIKE TRACE ELEMENT AND RADIOGENIC ISOTOPE SIGNATURES (E G 87SR/86SR UP TO ABOUT 0 717) INTRA-APENNINE (*0 8–0 25 MA) SAN VENANZO (0 26), CUPAELLO (0 64), POLINO (0 25), ACQUASPARTA (0 39), ORICOLA (0 53), COLLE FABBRI (0 8), ETC - MONOGENIC MA?C TO FELSIC PYROCLASTIC CENTRES AND RARE MA?C LAVAS WITH AN ULTRAPOTASSIC MELILITITIC (KAMAFUGITE) COMPOSITION CALCITE-RICH PYROCLASTIC AND SUBVOLCANIC ROCKS INTERPRETED AS CARBONATITES MELILITOLITES OF DUBIOUS ORIGIN AT COLLE FABBRI TRACE ELEMENT AND RADIOGENIC ISOTOPE COMPOSITIONS SIMILAR TO THE ROMAN PROVINCE ROMAN (LATIUM) (>0 8–0 02 MA) VULSINI (>0 6–0 13), VICO (0 4–0 1), SABATINI (0 8–0 09), COLLI ALBANI (0 6–0 02) - LARGE VOLCANIC COMPLEXES (VULSINI, SABATINI) AND STRATOVOLCANOES (VICO, COLLI ALBANI) FORMED OF POTASSIC (TRACHYBASALT TO TRACHYTE) AND ULTRAPOTASSIC (LEUCITE TEPHRITE TO PHONOLITE) PYROCLASTICS AND MINOR LAVAS HIGH ENRICHMENTS IN INCOMPATIBLE ELEMENTS 87SR/86SR AROUND 0 709–0 711 (CONTINUED)