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The Aeolian Islands form one of the most active geological structures in the Mediterranean area, comprising a number of active (Stromboli and Vulcano) and dormant (Panarea and Lipari) volcanoes. They have attracted the attention of scientists in modern and historical times and are the cradle of the scientific discipline of volcanology.

This Memoir provides information on geological features of the Aeolian Islands volcanoes at a regional scale and for each island. The stratigraphy, structural evolution, eruptive and magmatic history of the Islands is presented, along with the geodynamic setting of the Aeolian volcanism and implications for magma origin and evolution processes. Particular focus is given to the active and dormant volcanoes and the related natural hazards.

It includes new 1:10 000-scale geological maps of the Aeolian Islands and bathymetric maps of sectors of the Aeolian archipelago, together with an extended dataset of rock compositions.

  1. Page 1
  2. Page 3
    Abstract

    The Aeolian volcanism (c. 1 Ma active) develops within the Africa–Eurasia convergence setting, which is characterized by the subduction of the Ionian plate below the Calabrian Arc. Deep earthquakes occur to the east of a tear fault that divides the Aeolian Islands into two sectors: (a) an eastern sector characterized by active volcanism, reduced crustal thickness, high seismic flux, low P-wave velocity (Vp) and attenuation (Qp) and NE–SW extension; (b) a western sector where a NNW–SSE compressive strain along a WNW–ESE-striking fault system is acting. The geophysical and structural features of the eastern sector are consistent with upwelling and SE migration of the asthenospheric mantle. The extensional and strike-slip strain allow the magma to upraise along dyke-like conduits and to erupt. Earthquake-induced strain changes may trigger volcanic eruptions and degassing episodes. The oldest volcanism (Pliocene–Early Pleistocene) was controlled by a WNW–ESE-striking tear fault related to the SE rollback of the slab. A new tear, the Tindari–Letojanni Fault System, started during the Middle–Late Pleistocene and represents the active western boundary of the subducting slab. The present-day Aeolian volcanism is associated with rifting processes developing within an arc collision zone.

  3. Page 13
    Abstract

    The seven Aeolian Islands exist in much greater volumes below sea level than above sea level; study of the submarine portions is therefore fundamental for a better understanding of the development of volcanism in the area, tectonic control from the regional structural setting and the morphological evolution of volcanic edifices. The interplay between destructive processes (marine erosion, mass-wasting and flank instability) and constructive processes in the growth and evolution of the Aeolian volcanoes is discussed based on a study of their present-day morphology. In particular, the distribution and characteristics of insular shelves in the shallow-water sectors of volcanic edifices are compared and discussed, considering that variable geological/local factors combined with sea-level fluctuations controlled the development and morphology of these features. It is proposed that submerged shelves may furnish relative chronological constraints for the development of the Aeolian volcanoes, enhancing present knowledge which is mostly based on subaerial portions.

  4. Page 27
    Abstract
    Corresponding author (e-mail: claudia.romagnoli@unibo.it)

    An updated bathy-morphological setting of the Aeolian Islands is presented, based on new detailed bathymetric maps of the western, central and eastern sectors of the archipelago. In recent years, the acquisition of multibeam swath bathymetry has greatly expanded knowledge of the submarine portions of the Aeolian volcanic edifices, revealing that their submarine extension is much wider than that of the islands. Indications given by the submarine setting are fundamental for better understanding of the evolution of volcanism and the control exerted by main structural lineaments, as well as to locate large-scale flank instability events and recent submarine eruptive activity.

    DVD: Bathymetric maps of the eastern, central and western sectors are included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic

  5. Page 37
    Abstract

    A stratigraphic approach to geological fieldwork and mapping of the Aeolian archipelago is performed by primarily using unconformity-bounded units (UBUs) in addition to lithosomes and classical lithostratigraphic units, which are the basic mappable units. Lithosomes are largely used to identify the localization of eruptive vents or non-volcanic source areas through time. The UBUs display an encompassing framework of correlation on a scale from local (single islands) to regional (Aeolian archipelago), by placing particular emphasis on the stratigraphic role played by Late Quaternary marine terrace deposits and widespread tephra layers (e.g. Brown Tuffs). By establishing a direct relationship between UBUs and time-stratigraphic units, the volcanic successions are readable in terms of different and successive Eruptive Epochs (separated by prolonged non-volcanic periods), which are characterized by distinctive eruptive vents and eruption types. As such, the UBUs allow the reconstruction of the main steps of geological evolution of a volcano as the result of the interplay between volcanic activity of local and external provenance, sea-level fluctuations and volcano-tectonic or regional fault lineaments.

  6. Page 55
    Abstract
    Corresponding author (e-mail: federico.lucchi@unibo.it)

    A regional framework for stratigraphic correlations in the Aeolian archipelago is provided by widespread tephra layers and Late Quaternary marine terrace deposits combined with the available radiometric ages. Several tephra layers of Campanian and Aeolian provenance extending back to c. 110 ka are reported. The most important key-beds are the Ischia Tephra (56 ka), the Grey Porri Tuffs (70–67 ka) and Lower Pollara products (27.5 ka) from Salina, the M. Guardia pyroclastics from Lipari (27–24 ka) and the Brown Tuffs from Vulcano (c.70–8 ka). Late Quaternary marine terrace deposits are recognized along the coastal slopes of most of the Aeolian archipelago. They record distinct interglacial sea-level peaks during marine isotope stages (MIS) 5 and 7 in a context of prevalent long-term crustal uplift. Key erosional unconformities bounding the terrace deposits are the F1, UI, L3 and UII (in stratigraphic order). They are the ravinement surfaces formed at the onset of MIS 7.3 (F1), MIS 5e (UI) and MIS 5c interglacial peaks (L3), and the subaerial unconformity formed during the MIS 5a sea-level fall up to the emplacement of Brown Tuffs (UII). These unconformities are important regional-scale markers for chronostratigraphic classification and correlation between distant islands of the Aeolian archipelago.

  7. Page 83
    Abstract
    Corresponding author (e-mail: federico.lucchi@unibo.it)

    The Alicudi composite volcano (western Aeolian archipelago) was constructed between c. 106 and 28 ka by lava flows, domes and strombolian scoriae erupted during six Eruptive Epochs, interrupted by periods of dormancy and three caldera-type collapses in the summit area. Marine Isotope Stage (MIS) 5a (81 ka) terrace deposits and widespread Brown Tuffs of external origin are recognized and provide important marker beds for regional stratigraphic correlations. Volcanism was of central type, under control of the summit caldera collapses with negligible influence of regional tectonic trends. Alicudi rocks are basaltic to high-K andesitic and have the most primitive petrological compositions (high MgO, Ni, Cr contents), the lowest Sr–O and the highest Nd–He isotope ratios (87Sr/86Sr=0.70352 to 0.70410; 143Nd/144Nd=0.51289 to 0.51279; δ18O=+5.0 to 5.6; 3He/4He–R/Ra=c. 6.5 to 7.1) over the entire Aeolian archipelago. Their composition and variation through time are the result of polybaric crystal–liquid fractionation of parental calc-alkaline basalts to give basaltic andesitic and andesitic derivative melts. These underwent crustal assimilation during ascent, with basalts being contaminated more strongly than andesitic magmas. Sr–Nd–Pb isotopes suggest source metasomatic modification by fluids from an oceanic-type slab, with a minor role for subducted sediments.

    DVD: The 10 000 scale geological map of Alicudi is included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic. Also included is a geochemical dataset for Alicudi.

  8. Page 113
    Abstract
    Corresponding author (e-mail: federico.lucchi@unibo.it)

    The geological history of Filicudi in the Middle–Late Pleistocene (246–29 ka) is described by four successive Epochs of activity separated by quiescence stages, erosional episodes during marine isotope stage (MIS) 7 and MIS 5 and the Vallechiesa sector collapse. The partially overlapping Casa Ficarisi, Fossa Felci and Chiumento stratocones and the Monte Guardia scoria cone are built up under control of the WNW–ESE regional tectonic trend, with a subsequent progressive south-eastwards shift and chemical differentiation towards the Monte Terrione and Capo Graziano domes. The Monte Montagnola dome (64 ka) and Case dello Zucco Grande pyroclastics (<56 ka) are the youngest products, together with the Canna neck (29 ka) of an independent volcanic centre offshore of Filicudi. Filicudi rocks are calc-alkaline basalts, basaltic andesites and high-K andesites with minor dacites. Incompatible elements increase from basalts to dacites, with much scatter. Sr, Nd and Pb isotopes show moderate variations. δ18O‰ of clinopyroxene phenocrysts ranges from +5.37 to +6.20, and shows the highest values in the mafic rocks. Geochemical data suggest a complex interplay of different evolution processes (fractional crystallization, crustal assimilation and mixing) for the various eruptive centres of Filicudi. Variable incompatible element ratios of mafic rocks are suggested to reflect source heterogeneity.

    DVD: The 10 000 scale geological map of Filicudi is included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic. Also included are a full geochemical dataset and xenolith data for Filicudi.

  9. Page 155
    Abstract
    Corresponding author (e-mail: federico.lucchi@unibo.it)

    Stratigraphic, structural, volcanological and geochemical data allow a detailed reconstruction of the geological history of the island of Salina (central Aeolian sector). Its subaerial volcanism (c. 244 ka to 15.6 ka) developed through six successive Eruptive Epochs interrupted by major quiescence periods, volcano-tectonic collapses and recurrent episodes of marine terrace formation during MIS 7 and MIS 5. Several stratovolcanoes were constructed by strombolian and effusive (Pizzo Capo, Monte Rivi, Monte Fossa delle Felci, Monte dei Porri) to hydromagmatic and subplinian (Monte dei Porri, Pollara) activity, with a general east–west shift of active vents, controlled primarily by the dominant NNW–SSE and minor NE–SW regional tectonic trends, and a progressive chemical differentiation of the erupted products from calc-alkaline basalts to rhyolites. The magma compositions and variations through time are the result of contamination of primary magmas derived from a subduction-modified mantle source with the Calabro–Peloritano lower crust and subsequent differentiation dominated by polybaric fractional crystallization. Magma mixing and mingling processes occurred during individual eruptions. The early basalts were fed from deep reservoirs located near the crust–mantle boundary, whereas the later andesitic to dacitic and, ultimately, rhyolitic magmas originated through combined assimilation and fractional crystallization processes in magma reservoirs at mid- to upper-crustal levels.

    DVD: The 10 000 scale geological map of Salina is included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic. Also included is a full geochemical dataset for Salina.

  10. Page 213
    Abstract
    Corresponding author (e-mail: federico.lucchi@unibo.it)

    The Lipari volcanic complex, situated in the central Aeolian sector, was constructed between c. 267 ka and medieval ages by various lava flows, scoriaceous deposits, lava domes (coulees) and pyroclastic products related to hydromagmatic and strombolian activities. The eruptive history of Lipari is described by nine Epochs of activity interrupted by dormant periods, volcano-tectonic phases and episodes of terrace formation during the Last Interglacial. Several partially overlapping volcanic edifices were active through time, mostly under control of the NNW–SSE and north–south (minor east–west) regional tectonic trends. The latest eruptive events of M. Pilato and Rocche Rosse occurred from AD 776 to 1220. Lipari rocks range from calc-alkaline basaltic andesites to rhyolites, with silicic rocks dominating during the last 43 ka. There is a clear increase in K2O and incompatible elements with time, with distinct trends for mafic-intermediate and silicic rocks. Sr, Nd and Pb isotope ratios are highly variable. Petrographic and geochemical data suggest AFC (assimilation plus fractional crystallization) and mixing as the main magma evolution processes, with important effects of crustal anatexis, in the context of a polybaric feeding system.

    DVD: The 10 000 scale geological map of Lipari is included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic. Also included is a full geochemical data set for Lipari.

  11. Page 281
    Abstract
    Corresponding author (e-mail: federico.lucchi@unibo.it)

    Vulcano is an active NW–SE-elongated composite volcano located in the central Aeolian archipelago. Based on available radiometric ages and tephrochronology, the exposed volcanism started at c. 127 ka and spread through eight Eruptive Epochs separated by volcano-tectonic events and major quiescent stages. Various eruptive centres and two intersecting multi-stage calderas resulted from such evolution. Vulcano geological history displays several changes of eruption magnitude, eruption styles and composition of magmas through time. Vulcano rocks range from basalt to rhyolite and show variable alkali contents, roughly increasing during time. Magmas with low to intermediate SiO2 contents and high-K to shoshonite affinity prevail in the early Epochs 1–5 (c. 127–28 ka), whereas intermediate to high-SiO2 shoshonite and potassic alkaline products dominate the last three Epochs (<30 ka). This sharp increase in silicic products is related to the shallowing of the plumbing system and resulting major role of the differentiation processes in shallow-level reservoirs. Radiogenic isotope compositions are variable (87Sr/86Sr=0.70424–0.70587, 143Nd/144Nd=0.51254–0.51276, 206Pb/204Pb=19.305–19.759, 207Pb/204Pb=15.659–15.752, 208Pb/204Pb=39.208–39.559) as a result of both source heterogeneities and shallow-level interaction of magmas with continental crust. The compositional variations of mafic magmatism with time suggest that the source zone changed from a metasomatized, fertile, ocean island basalt- (OIB-) like mantle to a metasomatized depleted lithospheric mantle.

    DVD: The 10 000 scale geological map of Vulcano is included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic. Also included is a full geochemical data set for Vulcano.

  12. Page 351
    Abstract
    Corresponding author (e-mail: federico.lucchi@unibo.it)

    The Panarea volcanic group is made up of dome-fields that are the subaerial culminations of a largely dissected volcanic complex mostly located below sea level. The correlation of marine isotope stage (MIS) 5 marine terrace deposits and numerous tephra layers, combined with the available radiometric ages, shows that the Panarea dome-fields mostly developed between c. 155–149 and 124–118 ka through the emplacement of successive lava domes, lava flows and minor pyroclastic products, interrupted by dormant periods and episodes of faulting in a context of regional uplift, plus volcano-related deformation. Recurrent explosive phases subsequently occurred in the area of minor islets at c. 100 ka (Punta Falcone), 67–56 ka (p1) and 24–8.7 ka (Drauto), together with the emission of the c. 54 ka Basiluzzo dome. The Panarea volcanic group is presently in a quiescent state with fumarolic activity and episodic gas outbursts. Panarea rocks show basaltic andesite and high-K basaltic andesite to high-K dacite and rhyolite compositions, with minor shoshonites. Radiogenic isotope signatures range between those typical of the western Aeolian islands and Stromboli. This reveals a heterogeneous mantle source, which resulted from migration of more primitive asthenospheric mantle from the west during slab rollback, and its admixture with more strongly contaminated Stromboli-type resident mantle.

    DVD: The 10 000 scale geological map of Panarea is included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic. Also included is a full geochemical data set for the Panarea volcanic group.

  13. Page 397
    Abstract
    Corresponding authors (e-mail: lorella.francalanci@unifi.it, federico.lucchi@unibo.it)

    Stromboli is famous for its persistent volcanic activity consisting of periodic discrete explosions alternating with lava effusion and more violent explosions. This paper presents a detailed reconstruction of the geological history of Stromboli and description of the characteristics and distribution of the volcanic units and structural features. Six main growth stages (Eruptive Epochs 1–6), in addition to the c. 200 ka activity of Strombolicchio, are recognized between c. 85 ka and the present day, displaying a magma composition ranging from calc-alkaline to potassic series which usually varies with changing Eruptive Epochs. The Epochs are subdivided into sequences of eruptions and characterized by dominant central-vent summit activity with episodic phases of flank activity along fissures and eccentric vents. The activity was repeatedly interrupted by erosional and destructive phases driven by recurrent vertical caldera-type (cc1–5) and sector (and flank) collapses (sc1–7) and generally associated with significant quiescences. The different serial character of the Stromboli rocks is associated with largely variable trace element contents and isotope ratios. These petrochemical characteristics together with our new stratigraphy indicate that magmas, generated in a heterogeneous mantle wedge, underwent complex differentiation processes during their ascent. Magmas are characterized by polybaric evolution residing in small magma reservoirs that are alternatively tapped by the different collapses.

    DVD: The 10 000 scale geological map of Stromboli is included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic. Also included is a full geochemical dataset for Stromboli.

  14. Page 473
    Abstract
    Corresponding author (e-mail: pistolesi@dst.unipi.it)

    Stromboli, the northernmost island of the Aeolian archipelago, is known for its persistent volcanic activity over the last several centuries and for its cone which, on clear days, is surmounted by a gas plume rising from its summit. The island hosts two settled areas: the village of Stromboli (c. 500 inhabitants) to the NE and that of Ginostra (c. 40 inhabitants) to the SW, both situated along the coast. In summer the number of residents grows considerably, reaching c. 5000 people. This paper provides a description of the present activity and reassesses volcanic hazards on the basis of data from a new monitoring system and from studies on the 2002–2003 and 2007 crises. The normal activity, that of mild Strombolian explosions, is occasionally interrupted by violent eruptions of variable scale (paroxysmal events) and lava flows. Volcanic hazards directly generated by eruptive activity consist of ballistic and tephra fallout, pyroclastic flows, lava flows, wildfires and minor lahars, presenting serious problems to the settled areas only occasionally. In addition to hazards directly related to eruptive phenomena, the Sciara del Fuoco depression has been the site of landslides at various scales, sometimes accompanied by the formation of tsunamis.

  15. Page 491
    Abstract
    Corresponding author (e-mail: angelo.peccerillo@unipg.it)

    The volcanic rocks of the Aeolian arc exhibit important within-island and along-arc compositional variations that testify to both geochemical heterogeneous mantle sources and different roles and intensities of shallow-level magmatic evolution processes. Calc-alkaline magmas are present on all islands, but dominate in the western arc and at Lipari and Panarea. Shoshonitic rocks are present on the central-eastern islands and are particularly abundant at Vulcano and Stromboli. Mafic and intermediate rocks comprise the bulk of older volcanic sequences for most islands. Rhyolites are restricted to younger activity of the central arc, and become particularly abundant at Lipari and Vulcano. Regional variations of incompatible trace element ratios and Sr-, Nd-, and Pb-isotope signatures in mafic-intermediate rocks document the variable composition of mantle sources, which were contaminated by different types of metasomatic fluids released from an oceanic slab in the western-central sectors and from oceanic slab plus sediments in the east. This metasomatism was superimposed over a heterogeneous mantle wedge, which had a mid-ocean-ridge basalt (MORB-) to ocean-island basalt (OIB)- type character passing from the centre to the margins of the arc. The OIB-type component in the external arc is attributed to asthenospheric mantle inflow from the Africa foreland, around the borders of a narrow slab during rollback.

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