P67_copertina_R_OK C August 20-28,2004 Florence - Field Trip Guide Book - P67 Leader: G.Mastrolorenzo AND PEOPLE ON THEENVIRONMENT VOLCANIC ERUPTIONS EFFECTS OFEXPLOSIVE PRIMARY ANDSECONDARY IN : AND RELATED EVENTS ACTIVE VOLCANISM 32 Volume n°6-fromP55toPW06 GEOLOGICAL CONGRESS Post-Congress nd INTERNATIONAL P67 21-06-2004, 10:58:08 The scientific content of this guide is under the total responsibility of the Authors

Published by: APAT – Italian Agency for the Environmental Protection and Technical Services - Via Vitaliano Brancati, 48 - 00144 Roma - Italy

Series Editors: Luca Guerrieri, Irene Rischia and Leonello Serva (APAT, Roma)

English Desk-copy Editors: Paul Mazza (Università di Firenze), Jessica Ann Thonn (Università di Firenze), Nathalie Marléne Adams (Università di Firenze), Miriam Friedman (Università di Firenze), Kate Eadie (Freelance indipendent professional)

Field Trip Committee: Leonello Serva (APAT, Roma), Alessandro Michetti (Università dell’Insubria, Como), Giulio Pavia (Università di Torino), Raffaele Pignone (Servizio Geologico Regione Emilia-Romagna, Bologna) and Riccardo Polino (CNR, Torino)

Acknowledgments: The 32nd IGC Organizing Committee is grateful to Roberto Pompili and Elisa Brustia (APAT, Roma) for their collaboration in editing.

Graphic project: Full snc - Firenze

Layout and press: Lito Terrazzi srl - Firenze

P67_copertina_R_OK D 27-05-2004, 15:00:36 Volume n° 6 - from P55 to PW06

32nd INTERNATIONAL GEOLOGICAL CONGRESS

ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS ON THE ENVIRONMENT AND PEOPLE

AUTHORS: G. Mastrolorenzo1, L. Pappalardo1, I. Ricciardi1, P.P. Petrone2

1Osservatorio Vesuviano - INGV Istituto Nazionale di Geofisica e Vulcanologia 2Università degli Studi di Napoli “Federico II” di Napoli, Museo di Antropologia

Florence - Italy August 20-28, 2004

Post-Congress P67

P67_R_OK A 27-05-2004, 15:11:18 Front Cover: Hazard maps for pyroclastic density currents relative to Campi Flegrei by S. Rossano, G. Mastrolorenzo, G. De Natale, (2004) Jour. Volcanol. Geotherm. Res., 132,1-14 (left) and Somma-Vesuvius by G. Mastrolorenzo, S. Rossano, G. De Natale, (2004) Jour. Volcanol. Geotherm. Res., submitted (right).

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Leader: G. Mastrolorenzo

Introduction presents the extreme south-western limit of this chain, Several pieces of evidence on the relations between separated from the southern coast of the continent by the geographic environment, the catastrophic events, the narrow Bocca Piccola sea channel. The western and the human context make the Campanian region a part of the plain degrades to the Tyrrhenian coast, point of reference for geo-archaeological research in which mostly features dunes to the north and volca- the world. In the last few years, specifi c studies fo- noes to the south. cused on the stratigraphy, eruptive mechanisms, and The Pontine volcanic archipelago and the volcanic -tectonic events, have revealed key evidence island of in the Neapolitan district, are the for expanding our knowledge of the eruptive pheno- offshore westernmost boundaries of the Campanian mena and their effects on the environment, human territory, limiting the Tyrrhenian bathyal plain. The settlements, and people. At present, a conspicuous middle-southern part of the Plain features two princi- range of geo-archaeological contexts are available pal orographic elements: the Campi Flegrei volcanic and easily recognizable and allow us to understand fi eld west of , and the Somma-Vesuvius strato- better the effects of natural events which act with volcano, east of Naples. different intensities and on different time scales. In a Since the Late Pleistocene, the Plain has been affected relatively small area, including the Campanian Plains, by subsidence, partially compensated by alluvial se- with its surrounding coasts and mountains, some ten dimentation and volcanic mass transport from Campi key sites, with well exposed sections, will allow us to Flegrei and Somma-Vesuvius, resulting in post-Wur- summarize the volcanological history of the area in mian seaward progradation. a trip lasting a few days. The itinerary also provides During the last 50 ka, an intense explosive activity, the opportunity to go on accurate guided visits to the with recurrent intervals in the order of 102 to 103 principal archaeological sites in Campania, and to the years, dispersed both primary and secondary pyro- museums, where fi ndings from the paleolithic age to clastic products over an area as wide as 10,000 km2, the medieval age are exposed. These bodies of evi- which includes the entire plain and the surroundings. dence and related studies provide a direct element for Catastrophic volcano-tectonic events, such as an interdisciplinary approach to hazard evaluation in collapses, and bradyseismic movements of as much an active volcanic context that can also be exported of tens of meters, induced important changes in the to other areas. territory. Stratigraphic studies reveal that from prehistory to The Campanian Plain the present time, both the Campi Flegrei and Som- 1.1 Geographic setting and active volcanism ma-Vesuvius areas, including the area of Naples and The ca. 3000 km2 wide Campanian plain, in southern the mountain reliefs, have been affected by volcano- Italy, is one of the Pleistocene-Holocene Italian coa- tectonic events (subsidence, bradyseism, and rapid stal plains bordering the and limited caldera collapse), as well as the coupled primary by the Apennine chain (Fig.1). deposition of volcanic products and secondary depo- The nearly rectangular fl at plain (average 30 m sition of volcanically induced mass fl ows. Selected a.s.l), is elongated in a NW-SE direction for about stratigraphic sections describe the volcanological 100 km, and occupies a wide, graben-like structural history of the area and the effects of the explosive depression, due to a main regional extension, in turn events on the human settlements. In particular, in the due to the complex stress fi eld produced by the great last two-thousand years, tensof catastrophic landslide collision between African and Tyrrhenian plates in the and fl ooding events have occurred. They have been Mediterranean area. recorded in the archeological stratigraphy and have Volume n° 6 - from P55 to PW06 n° 6 - from Volume The plain is confi ned to its north-western border by often been reported in historical chronicles. Mt. Massico, and by the old Rocca- Analysis of historical reports, integrated with fi eld monfi na (1005 m a.s.l.). On the northern and eastern recognition, and laboratory analyses, reveal that such Campanian Plain edges, the boundaries consist of the events range over a relatively wide size interval, whi- barrier of the fi rst ridges of the Apennine Chain. To ch includes nearly all types of phenomena induced by the east and south-east lies the Monti Lattari chain extreme precipitation, volcanic and seismic activity, (1444 m a.s.l.), which curves to the south towards the slope instability and human modifi cations, which Sorrentine peninsula (Fig.2). The Island of re- represent a signifi cant aspect of the prevailing geolo-

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo tle, variably enrichedinincompatible elements,radio- The sourceofmagmatismhasbeenlocatedinaman- tophonolite,alsooccur. Appleton (1972),rangingincompositionfromalkali- to highlyundersaturatedrocksbelongingHKSof widespread products. At Somma-Vesuvius, mildly from shoshonitetotrachy-,thatarethemost series of Appleton (1972),andrangeincomposition The Campanianvolcanic rocksbelongtotheKS 1.2 Magmagenesisandevolution are described(Fig.3). examples ofvolcanic andvolcanically inducedevents canic stratigraphyandstrikingprehistorichistoric In thefollowing paragraphs,descriptionsofthevol- gical hazardintheCampaniaregion. Figure 1-DigitalElevationModelimageoftheCampanianPlain. mantle-derived fl agents ofenrichmentthathave beenidentifi genic SrandunradiogenicNd.Debateexists aboutthe contribution becomesmorepronouncedmoving upper enrichedlithosphericmantlesource. The last which alsothe Tyrrhenian magmasderived, andan region: adeeper asthenospheric mantlesource,from the genesisofmagmaseruptedinCampanian al., 2003,proposedtwo different mantle sourcesin type mantle(e.g.D’Antonioetal.,1996).Piochi Beccaluva etal.,1991;Peccerillo, 2001)oraMORB- references therein)whichmodifyaOIB-type(e.g. undergoing oceanic slab(e.g.Peccerillo,2001,and Vollmer, 1989)orb)fl (e.g. Hawkesworth and Vollmer, 1979;Cundari,1980; uids inaintra-platetectonicsetting uids ormeltsreleasedbyan ed asa) 27-05-2004, 15:11:45 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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magmatic system. In particular, the existence of both deep and shallower crustal reservoirs has been pro- posed in several studies of the Campanian volcanoes (Marianelli et al., 1999; Piochi et al., 1999; De Astis et al., 2002; Pappalardo et al., 1999, 2002). Inside the Phlegraean Volcanic District, constituted by Campi Flegrei, , and Ischia, the deeper reservoir was tapped by the regional fault system during eruptions, thereby extruding the least evolved magmas that mingled during ascent with magmas evolving at shal- lower depth.

The Campi Flegrei volcanic fi eld 2.1 Geological setting and volcanological evolution Since past centuries, the Campi Flegrei volcanic fi eld has been one of the classical subjects of the internatio- Figure 2 - Location map of Naples Bay, which lies in the nal geological literature, and among the most famous southern portion of the Campanian Plain. A northeast- volcanoes in the world. Even if only one eruption has southwest volcanic zone, identifi ed by three volcanic been documented by eye-witnesses in historical times, centers Campi Flegrei, Procida, and Ischia-defi nes the northwest boundary of Naples Bay. Hatched lines show since prehistory the interest for the Campi Flegrei has the major normal faults identifi ed by Finetti and Morelli been stimulated by a variety of natural phenomena. (1974). Additional normal faults have been added from These include hot springs, fumarolic exhalations in the geological map of Ischia (Consiglio Nazionale delle the Solfatara crater and other sites, ground movemen- Ricerche, 1986), and from results of a detailed seismic ts, (bradyseism) and earthquakes. refl ection survey conducted along the undersea portion The most conspicuous geological feature of Campi of Campi Flegrei (Pescatore and others, 1984). Flegrei is a 12 km wide, collapsed caldera, outlined from offshore volcanoes (Ischia and Procida Islan- on land by a discontinuous ring shaped hilly morpho- ds), through onto land volcanoes (Campi Flegrei and logy with inward-facing scarps enclosing the volcanic Somma-Vesuvio), likely in response to the thickening fi eld (Fig. 4). of the lithosphere observed under the Peninsula. The caldera rim, inferred in scattered points by the Major and trace elements, Sr-Nd-Pb isotope variations stratigraphic sequence (Camaldoli hill), ranges in shown by the Campanian rocks has been attributed to elevation between about 450 meters and a few tens of complex evolutionary processes, involving magma meters, and one third of it continues below sea level, chamber refi lling, magma mixing, and crustal assi- forming Bay. A few submerged volcanic milation by mantle-derived magmas in a multi-depth relicts represent the submerged part of the volcanic fi eld. The southern limits of the caldera are poorly known and mainly inferred by the geophysical investigations. A near vertical fault system defi nes the geometry of the central depression, which characterizes the nearly perfectly circular caldera structure. The intracalderic area of Campi Flegrei shows the typical features of a volcanic fi eld characterized by different land forms. Volume n° 6 - from P55 to PW06 n° 6 - from Volume It includes closely-grouped volcanic hills, coalesced craters, depressions bordered by steep, eroded volcano fl anks, and fault scarp faces, crater-fi lling lakes, and relicts of an- cient marine terraces. The few major intracalderic plains of Fuori- Figure 3 - May 5 - 6, 1998, Sarno fl ooding grotta, , , S.Vito, Quarto, and and landslides events.

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo sical methods,coincidewiththedeepdislocationin caldera rims,recognizableinthefi meter collapseofthecalderainnerpart.Indeed ca. 12,000yrB.P., andcaused theseveral hundred , recognizedasauniquegiant eruption,occurred largest event thatgeneratedtheNeapolitan Yellow yr B.P. (De Vivo etal.,2001); whilethesubsequent and even theearlycalderadepressionareabout39000 volcano-tectonic events. The CampanianIgnimbrite and moreeffective constraints ontheagesofmain objective controlonthestratigraphiccorrelations, Accurate geochronologicalanalysesnow supplyan the beautifulphysicalsettingofterritory. no, andLucrinolakes) createdbysandbarscomplete ts). Littoraldunesandlagoons(Patria, Fusaro,Mise- the seaordislocatedbyfaults (volcano-tectonic even- cliffs arenaturalsectionsofvolcanic coneserodedby of alluvialplains,andthesteep,mostlytuffaceous, principal types:thelows arebeachesatthetermination The coastsofCampiFlegrei canbegroupedintotwo sodes. areas, duetolocalmovement following eruptive epi- La Schiana,areassociatedwithlocalizedsubsidence Yellow Tuff. Pomici PrincipaliPlinianformation; TGN=Neapolitan MO =Minopoliviolentstrombolianformation; PP= cone; SF=Solfataratuff ring;SG= Sengaspattercone; MSA =MonteS. Angelo pliniandeposit;NI=Nisidatuff MS =MonteSpinasmallscalepyroclasticfl cone; MP=MontagnaspaccataStrombolianformation; cone; MI=Misenotuff ring;MN=MonteNuovo cinder pyroclastic fl tuff ring;BA =Baiatuff ring;BM =BrecciaMuseo volcanic formations.: AS = Astroni tuff ring; AV = Averno volcanic fi Figure 4-DigitaltopographicmapoftheCampiFlegrei eld, includingmonogeneticvolcanoes and ow formation; FB=Fondi diBaiacinder eld andviageophy- ow formation; (150 km ka, withthecatastrophiceruptionofvoluminous culminated intheformationofcalderaatabout39 SW tectoniclineaments,andthisfi erupted preferentiallyfromvents locatedalongNE- the initial100–44kaperiod,trachyticmagmaswere minantly trachyticmagmasinthelast100ka.During a large shallower magmachamberthateruptedpredo- The magmaticsystemofCampiFlegrei consistedof 2.2 The magmaticsystem genetic events). from sometensofdistinctive scatteredvents (mono- consisted ofatleast60eruptions,mostlyexplosive, which occurredafterthissecondcalderacollapse, after thateruption. The intracalderaeruptive activity sting theNeapolitan Yellow Tuff, was alsorenewed confi the Neapolitan Yellow Tuff formation. This evidence Ignimbrite. The ageofCampanianIgnimbriteisde- notable forhaving greatthicknessesofCampanian This depression,andtheoneeastofLagoPatria, are suggest was asourcefortheCampanianIgnimbrite. near , northeastofCampiFlegrei, whichthey evidence foralarge depressionoftectonicorigin the CampiFlegrei. Scandoneetal.(1991)present Ignimbrite was aNW-SE trendingfracture,northof (1984), suggestedthatthesourceforCampanian al., 1996).Barberietal.(1978)andDiGirolamo 1987; Barberietal.,1991;Orsi1996;Rosi the CampanianIgnimbriteeruption(RosiandSbrana, authors relatetheCampiFlegrei calderacollapseto at distalexposures inthe Apennine valleys. Some encountered mountainsatleast1000mhightoarrive Campanian PlainnorthofNaples.fl the SorrentoPeninsula,andunderliesmuchof ,Roccamonfi from Naples.Itcropsoutinisolatedvalleys inthe trachytic depositexposed inanareawithin80km The CampanianIgnimbriteisanUpperPleistocene Neapolitan YellowTuff. the CampanianIgnimbriteand 2.3 The caldera-forming eruptions: ved reservoir. fault systemthatprobablytappedadeeperleast-evol- activity, throughvents locatedonaNE-SWregional were eruptedonlybetweenthe12and8kaperiodof nately latiticincomposition. Trachybasaltic magmas inside thecalderarim,andwas trachyticandsubordi- posits. Following thiseruption,magmatismcontinued rms thatthegrounddepression,partiallypre-exi- 3 DRE)trachyticCampanianIgnimbritede-

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fi ned at 39 ka by De Vivo et al.(2001) on the basis of from the eruptive vent (Pappalardo et al., 2003). The new 40Ar/39Ar data. Moreover, the products of three fl ows are believed to have traveled in the form of a periods of trachytic ignimbrite volcanicm (289-246 buoyant, highly expanded cloud of eruptive mate- ka; 157 ka, and 106 ka) have been identifi ed in the rial which overtopped Apennine ridges higher than Apennines by Rolandi et al.(2003). These deposits 1,000 m and the Roccamonfi na volcano, whose top represent distal ash fl ow units of ignimbrite eruptions is located at 1.100 m a.s.l.. Anisotropy of Magnetic which occurred in the Campanian area in the last 300 Susceptibility Measurements (AMS) fl ow directions ka. show that the pyroclastic currents moved radially Proximal facies: breccia deposits, which were na- from the eruptive vent. Pyroclastic currents were med Museum Breccia by Johnston-Lavis (1889) generated by defl ection of these fl ows, which draped occur along the slopes bordering the Campi Flegrei themselves over the local relief, and fl owed towards caldera, and on the island of Procida. These deposits lower elevations (Ort et al., 2002). In contrast, com- have been interpreted either as proximal facies of the puter simulations (Rossano et al, 1996), indicate that Campanian Ignimbrite, on the basis of stratigraphical, the surface distribution of Campanian Ignimbrite is sedimentological, and compositional characteristics consistent with a radial propagation of pyroclastic (Rosi and Sbrana, 1987; Rosi et al., 1996) or as the density currents, at a speed of ca 160 m/s from a vent products of variable local eruptions (Di Girolamo et area located north of Naples. al., 1984; Perrotta and Scarpati, 1994; Melluso et al., 1995). One of the main points to support the hypothe- The Neapolitan Yellow Tuff (NYT) was produced du- sis of many local vents, is the scattering of the age of ring one of the greatest eruptions of the Campi Flegrei the variable outcrops. Lirer et al. (1991), have presen- caldera, and is by far the largest trachytic phreatopli- ted 14C ages detected on paleosol samples collected nian deposit known. The NYT crops out in scattered at Procida and , at the southwestern outcrops over an area of ~1,000 km2, with a conser- corner of the Campi Flegrei caldera. The ages span vatively estimated volume of ~40 km3 (DRE). It has from 17.3 to 26.7 ka, while Deino et al. (1992), have been dated at around 12 ka ( Scandone et al., 1991), obtained a mean age of 36.2 ka for Campanian Ignim- and outcrops mainly in the steep relief bordering the brite distal and breccia deposits, using the laser-fusion Campi Flegrei caldera. In the caldera depression, the 40Ar/39Ar dating technique. thickness varies between a few meters to more than Distal facies: the Campanian Ignimbrite (CI) is 100 m, and is mostly covered by younger pyroclastic partially to non-welded throughout its extent, but is deposits. The formation is mainly hydromagmatic, lithifi ed by zeolites in some localities, where it is >10 and consists of two main diagenetic facies; a yellow, m thick. The stratigraphy and general characteristics lithifi ed, unwelded facies rich in zeolite, and a gray, of the CI are described in Barberi et al. (1978), and non-lithifi ed facies called “Pozzolana” (Scherillo, Fisher et al. (1993). It is thickest in quarries in the 1955). Both vertical and lateral transitions between Volturno Plain, north of Campi Flegrei, in the valleys the two facies occur, even over a few meters. The stra- of the Apennine Mountains, and near the shore on the tigraphic and sedimentological analysis of the NYT Peninsula, across the Bay of Naples from (Cole and Scarpati, 1993; Orsi et al., 1992; Wohletz et Campi Flegrei. At about 500 km3 bulk volume and al. 1995). indicates the presence of a lower member, 150 km3 DRE (Civetta et al., 1997), it is the product consisting mainly of fallout units, and an upper hydro- of the largest eruption of the Mediterranean region magmatic one. The lower member is more widespread in the last 200,000 years (Barberi et al., 1978), and than the upper, and outcrops both inside and outside covers an area of about 30,000 km2. The Campanian the caldera, with thicknesses varing between about 10 Ignimbrite includes an eastward-dispersed, Plinian m close to the caldera rim, to less than 1 m in distal lo- fallout deposit (e.g. Polacci et al, 2003 and references cations. It exibits a thin stratifi cation of phreatoplinian therein), overlain by ignimbrite. However Rolandi et fall-out and surge layers, with a prevailing fi ne-grai- P55 to PW06 n° 6 - from Volume al. (2003), proposed that the fallout deposit ned fraction. In contrast, the upper member consists derived from a different source, located near the of a thick, coarse-grained pyroclastic fl ow and surge Naples area. Most of the tuff was emplaced by pyro- sequence, with subsidiary fall-out units. The eruptive clastic fl ows which erupted in three major pulses, fed mechanism and the location of the vent have been by magma with different compositions, that moved controversial. Two contrasting hypotheses have been in variable directions and reached variable distances proposed: a) the products were emitted at different

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo km caldera (Lireretal.,1987)withasurface extent of90 suggest thattheeruptionresultedinformationofa eastern partofthecalderadepression.Someauthors 1996), suggestingthatthelocationofvent isinthe magnetic susceptibilitystudies(DeGennaroetal., analyses. Itisalsosupportedbytheanisotropy of strongly supportedbyrecentdetailedstratigraphical mo etal.,1984;Lirer1987). The lattertheoryis and Franco,1967;LirerMunno,1975;DiGirola- was generatedfrom asinglehugeeruption(Scherillo 1946; Rittmannetal.,1950);andb),theformation times fromdifferent eruptive centers (Parascandola and thedepositfeatures (i.e.,theheighttowidthratioofpyroclastic cone). Wohletz (1986).Thepositionofeach formation intheeffi Figure 5-PlottingoftheselectedhydromagmaticdepositsCampiFlegreiinexperimentaldiagramproposed by from achambercontainingthreediscretemagma products refl two clinopyroxenes. The compositionoftheerupted and alkalitrachyte,reversely zonedplagioclase,and sanidine inlatite,anorthiticplagioclasetrachyte, logical disequilibriaareevidenced by xenocrysts of nopyroxene, biotite,magnetite,andapatite. Minera- with rarephenocrystsofsanidine,plagioclase,cli- of aphyrictosubaphyriclatitesalkalitrachytes, Ignimbrite (Orsietal.,1996). The NYTiscomposed caldera associatedwiththeeruptionofCampanian tely 600mnearitscenter. Itisnestedwithinanearlier 2 , withaconsequentialdown dropofapproxima- ects acomplex mechanismofextraction ciency diagramhasbeenbasedonthegrainsizecharacteristic magma/water interaction(DiGirolamoetal,1984; and tuff ringsresultfromtheincreasing effi through Strombolianactivity, cindercones,tuff cones, scoria conesandspattercones,whichwereformed placement oftheNeapolitan Yellow Tuff. Apart from activity atshallow depth,andoccurredaftertheem- ranging over theentirerangeofhydromagmatic by acloselygroupedassortmentofpyroclastic cones, intracalderic landformofCampiFlegrei isdominated the totalvolume ofthevolcanic products. The present, and domes,contributes onlytoasmallpercentageof eruptions. Effusive activity, withassociatedlava fl forming explosive magmaticandphreatomagmatic Plinian eruptionsandmoderatetosmallscalecone- canic phenomenarangingbetweenlarge ignimbrites, been mainlyexplosive. Itincludesavariety ofvol- Since theonset,volcanism ofCampiFlegrei has 2.4 The recent monogeneticvolcanic activity chamber (Orsietal.,1992). the arrival ofnew trachytic-to-latiticmagmaintothe The eruptionwas likely tohave beentriggeredby chamber bymagmabatchesofvariable composition. tifi layers co-mingledduringeruption.Pre-eruptive stra- cation resultedfromthestep-fi lling ofthemagma ciencyof 21-06-2004, 10:59:09 ows ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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Di Vito et al, 1985; Rosi and Sbrana, 1987; Mastro- along a NNW-SSE direction in the western part of lorenzo, 1994; de’Gennaro, 1999; Mastrolorenzo et Campi Flegrei (, Porto Miseno, , Fondi al. 2001) (Fig. 5). di Baia, Baia, Averno, and the submerged volcanoes About 90% of the recent caldera fi lling consists of Bank of Miseno, and Penta Palummo) agree with of pumiceous tuff and mainly unconsolidated ash, the seismic profi les, indicating a possible, major re- emitted in phreatomagmatic eruptions. The surface cent intracalderic tectonic structure. distribution of the monogenetic volcanoes refl ects the Other volcanic formations and edifi ces that were tectonic and volcano-tectonic evolution of the caldera formed after the emplacement of the Neapolitan that, in turn, controlled the magma conduit position Yellow Tuff, result from eruptions that range in size and the main ground collapses (Rosi et al, 1983). and explosivity between those of Mt. Nuovo and Mt. On the basis of accurate dating and paleosoils reco- Astroni (0.02 km3 to 0.5 km3). Moreover, a least three, gnition, the recent cycle of activity has been divided subplinian and Plinian eruptions formed pyroclastic into two main phases: an old phase, ranging between sheets not directly related to a specifi c cone (Lirer et the emplacement of the Neapolitan Yellow Tuff (ca al, 1987). Some small scale pyroclastic fl ows are both 12,000 yrs B.P.) and about 8,000 yrs B.P., and a included in more complex cone-forming sequences, young phase, started about 4500 yrs B.P., and still and sometimes were erupted as a prevalent part of in action. The two phases were separated by a long an eruption that fi lled valley and cone depressions. period of repose, which generated thick palaeosoils. Strongly subordinate lava fl ows were erupted also Near the end of this interval, major volcano tectonic from vents located near the caldera center (Monte events caused the uplift of a central caldera block Olibano, Accademia near Pozzuoli, La Caprara, and (Cinque et al, 1985). This event is recorded in the the Rotondella in the Astroni complex). marine terrace, La Starza. This is a ca. 5 km long The pyroclastic cones of Campi Flegrei represent cliff parallel to the northern coastline of Pozzuoli, more than 90% of the total volcanic formation in formed by alternate pyroclastic and marine deposits the last 12,000 years. Usually they reach 100 to 200 that record three separate transgressions of the sea, meters in height. However the rim of the great Mt. which occurred between 8,400 and 4,000 years ago. Barbaro tuff cone, in the middle part of the caldera, Absolute dating of the different deposits indicates that is about 340 m high. The basal diameter of the cones the uppermost marine layer was uplifted at least 40 m ranges between less than 1 km and about 3 km, while in less than 3000 years. The uplift was possibly due the craters range in diameter between less than 500 m to a magma injection that announced a new intense and about 1.5 km. eruptive phase. During the early phase, the eruptions occurred from 2.5 The last eruptions different vents located on the western and central (from Bronze to Modern age) eastern caldera sectors (Rosi et al, 1987; Lirer et al, From ancient Bronze to the Modern age, an intense 1987). Near the end, the activity migrated toward the monogenetic explosive and subordinate effusive acti- center of the caldera and the Plinian deposit of the vity took place from vents located within the central Pomici Principali was erupted from the Agnano area part of the caldera (Fig. 6). (age ca. 10,000 years), as well as those of Baia and Solfatara, Astroni, Averno, and Monte Nuovo pyro- Fondi di Baia (8,400 years B.P.). The volcanic activity clastic cones, Agnano and Monte Spina Plinian to of the latest phase is not regularly distributed both in phreatomagmatic eruptions, and Monte Olibano and time and space, since most of the eruptions are cluste- Accademia lava domes are the principal events that red between 4,400 and 3700 years B.P. The eruptions modifi ed the inner part of the volcanic fi eld, and occurred from vents located both in the central and affected the human context from prehistoric to histo- western parts of the caldera. A special concentration rical times. of explosive eruptions occurred around the center of P55 to PW06 n° 6 - from Volume the caldera. Cigliano, Mt. Spina (4,500 yrs B.P.), Sol- 2.5.1 The Averno eruption fatara, Monte Olibano, Astroni, Senga, Averno (3,700 The tuff ring of Averno, located about 4 km Northeast yrs B.P.); and Monte Nuovo formations, all younger of Pozzuoli, was formed ca.3,700 years B.P. It is a than 4,500 yrs B.P., lie within a distance of 4 km from wide, lake-fi lled volcano (Fig. 7). The crater rim is Pozzuoli town (Lirer et al, 1987, and Rosi and Sbrana, about 1000 m across, and the maximum rim elevation 1987). Moreover, a particular alignment of volcanoes is ca.100 m. It has been classifi ed as a type of

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo as 50km The productsofthiseruptioncovered an areaaswide yellow tuff basement(Mastrolorenzo,1994). explosions carved adeepcraterinthe pre-existing hydromagmatic cone,becausetheviolenceof the coastofBaia,Cuma,andFusarolagoon. fi Figure 6- Aerial photographofthewestern part oftheCampiFlegreivolcanic Monte Nuovo pyroclasticcone. ring, borderedbythefl Figure 7-Theso-called Apollo Temple intheeasternlower sideofthetuff 1994). Detailedpetrochemicalanalysisof Averno sits isca.300millioncubicmeters(Mastrolorenzo, eld, includingthe Averno tuff ring,MonteNuovo, 2 . The totalvolume ofitspyroclastic depo- ank oftheolderGaurotuff cone,andtheyounger volcanoes thatoccur. determined theeruptive styleand,hencethetypeof weaknesses. Itisthenatureofsuchacouplingthat tracalderic hydrogeologicalsetting,andthestructural confi in themiddlecalderaarea. These piecesofevidence rm therelevance ofthecouplingbetweenin- lapilli andash.Sothehydromagma- after themagmafragmentationinto tion intheconduit,andfrequently mainly occurredafterthegas exolu- cates thatthemagma-water contact (Mastrolorenzo etal,2001),indi- of different pyroclastic deposits detailed comparative studyoftens have taken placeintheconduit. A mechanisms thatareassumedto scale evidence thatconfi small ashparticles,furnishes Electron Microscopy (SEM)of scopic analysis,byusingScanning magma chamber. Detailedmorpho- a local,narrow, apicalpartofthe gests thattheeruptionwas fedby alkali . This evidence sug- basal peralkalinetrachytetoupper compositional stratifi pyroclastic productsshow aregular controlled bythelocalstressfi magma dykes, whoseascentwas of localizedandrelatively small which was relatedtotherising Strombolian backgroundstyle, tic activity tookplaceonasimple (Da Toledo, 1538,DelliFalconi, struct themainphasesofactivity 9), ithasbeenpossibletorecon- From contemporaryaccounts(Fig. pi Flegrei (Fig.8). the onlyhistoricaleruptionofCam- Nuovo, 3kmwestofPozzuoli.Itis resulted intheformationofMonte September 1538,andinoneweek The lasteruptionstartedon29 2.5.2 The MonteNuovo eruption ze theCampiFlegrei district. ground deformationthatcharacteri- canic activity, seismicevents, and unsolved relationbetweenthevol- caldera areconfi eruptive processesinanactive This inferredcomplexity ofthe rmed bythestill cto from cation rs the rms 27-05-2004, 15:11:57 eld ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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the temporary exhaustion of the water reservoirs (Di Vito et al, 1987). Nevertheless, according to the contemporary chroni- cles, at least 24 people were killed by the last phase of the eruption. The town of Pozzuoli, evacuated by the inhabitants, suffered seve- re damage both because of the seismicity and because Figure 8 - The Monte Nuovo pyroclastic cone. of the eruption. The village of Tripergole was buried under the products of the eruption. Tile fragments interbedded in the pyrocla- stic deposits testify to this catastrophe. Even though it was completely explosive, the erup- tion of Monte Nuovo was actually a relatively minor event, both in terms of its violence and the total erup- ted volume (about 20 million cubic meters of magma involved).

2.6 The ground movements: bradyseism and related earthquakes The bradyseism, a slow ground movement, is the most intriguing phenomenon in Campi Flegrei. Figure 9 - Woodcut engraving that depicts the September The peculiar geographic condition of the caldera, 1538 eruption of Monte Nuovo (MOTE NOVO). This partially submerged, represents a reference level for engraving accompanied the publication of the eyewitness relative ground movements in an active volcanic area. account of the eruption, written by da Toledo (1539), Marine deposits, tracks of uplift or subsidence of Ro- published in Naples by Giovanni Sultzbach man ruins, and historical documents, provide a more on January 22, 1539, Baia. than 2,000 years long record of local relative sea level 1538, Di Vito et al, 1987; Lirer et al, 1987; Mar- changes (Dvorak and Mastrolorenzo, 1991). Among chesiono, 1538, Parascandola, 1943, 1946; Simone the several known Roman coastal ruins, the most Porzio, 1551). The eruption concluded a period of studied is the Roman marketplace in Pozzuoli, also local ground uplift which started a few tens of years called Serapis (Fig. 10). Marine molluscs, lithodomus before. A further rapid uplift, in the vent area, occur- lithophagus, have bored into it and left shells into its red two days before the eruption, and was observed three standing marble columns, recording ancient by the inhabitants of Pozzuoli. The fi rst two days of relative sea level changes. The monument has been the eruption were characterized by moderate energy the object of much research, beginning shortly after hydromagmatic activity, and led to the growth of the its excavation in 1750 (Niccolini 1839, 1845; Para- main body of the cone around the vent. After four scandola, 1947). days of relative quiescence, interrupted by explosions However ground movements interest a wider area, in- of Strombolian type, a last phase concluded the erup- cluding the entire caldera. Geological, oceanographic, P55 to PW06 n° 6 - from Volume tion with the emplacement of a directional, small-sca- and archaeological research has been integrated to le pyroclastic fl ow deposit. Field evidence indicates outline a better temporal and spatial description of that the style of activity varied signifi cantly over short the bradyseism. Furthermore, since the past century, periods of time, from hydromagmatic to magmatic. investigations of the possible causes of the phenome- This fact suggests that the main factor governing na have been carried out by a number of scientists. the eruption was the interaction of rising magma and Breislak (1792) fi rstly suggested that the perforations water. The fi nal stage of the eruption possibly testifi es and marine shells resulted from changes in relative

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo Mogi (1958),they consideredthegroundmovement (Corrado etal.,1977).Following aprevious modelby Neapolitan researchersinthesecondhalfof1970s fi possibly byself-compactionoftheporousdeposits ter. Onthecontrary, thesubsidencehasbeencaused to thesuddenheatingandexpansion ofgroundwa- that precededtheeruptionofMonteNuovo was due dyseism. According totheirmodel,therapiduplift blished thefi Oliveri delCastilloandQuagliariello(1969)pu- Naples sinceRomantimes. along thecoastlineofPozzuoliBayandcity stal movement, andoutlinedthehistory ofbradyseism collected several piecesofevidence forvertical cru- during theeruptionofMonteNuovo in1538 A.D. He seism, andinparticular, oftherapidupliftrecorded century, carriedoutdetailed analysisofthebrady- sea level. Parascandola, midway throughthe20th the relative movement withaworld-wide changein Niccolini (1845),andGunther(1903),whoexplained heating processes. A different thesiswas publishedby Lyell associatedthegroundmovement tocoolingand a vertical movement oftheland.BothBabbageand (1872) alsoconsideredthephenomenaasresultof position. Forbes (1829),Babbage(1847),andLyell monument, andthesecondupliftedittopresent two earthquakes: thefi was duetoagrounddisplacementassociatedwith Pozzuoli Bay. Hefurthersuggestedthatthischange sea level atRoman Age sitesalongtheshorelineof Serapis Temple Figure 10-RomanMarketplace inPozzuoli: lling thecaldera. A different modelwas proposedby rst modernphysicalmodelforthebra- rst earthquake lowered the Figure 11-Resultsoflevelling surveys conductedbetween December 1984amountedto180cm. The raisedarea The totalupliftrecordedbetweenJanuary1982and sion of550earthquakes was recordedon April 1st. about 170cm. The patternofthegrounddeformation sing ofabridgeandwharf. The totalgroundupliftwas Pozzuoli whonoticedtheoffset ofwalls, andtherai- of thefi December 1984(Barberietal.,1984). The beginning occurred from1969to1972,andmid-1982 period ofuplift. Two distinctepisodesofbradyseism the researchwas associatedwithasecondhistorical within ashallow magmachamber. A new impulseto as adirectconsequenceofmagmapressureincrease rst phasewas recognizedbytheinhabitantsof The isolinesofgrounddeformation areinmm 1983. The town was evacuated, Pozzuoli, occurredonOctober4, 4 earthquake withitsepicenterin damage inPozzuoli. A magnitude 1984, andresultedinstructural from mid-1983toDecember (depth from1to4km)occurred Shallow earthquakes hypocenters (Dvorak andGasparini, 1991). companied byintenseearthquakes previous one,thisepisodewas ac- uplift pattern.Incontrastwiththe second crisispresentedasimilar recorded duringthisphase. The only aweakseismicactivity was center nearPozzuoli.However, was anearlycircularlens,withthe March-April 1984,andasucces- energy was releasedintheperiod transferred. The maximumseismic and about40,000peoplewere (Dvorak andMastrolorenzo,1991). January 1982andJanuary 1985. 27-05-2004, 15:12:02 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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was circular and had a radius of about 6 km, again der younger volcanic deposits. centered on Pozzuoli town (Fig. 11). The activity of the Somma strato-volcano ended with A number of scientists are involved in research on the the caldera-forming event about 17,000 years BP. dynamic of ground movements and additional data The following activity was mainly located within the have been collected about the evolution of the pheno- summit caldera, at an elevation exceeding ca 500 m mena (Luongo et al, 1991). asl, and only subordinately at a lower elevation on Results of recent research have given new likelihood the southern slopes of the volcano. K-Ar dating of the to the model which is based on the thermal expansion Monte Somma lavas indicates an age between 20,000 of water-saturated deposit fi lling the caldera depres- and 30,000 years, consistent with the age of the fi rst sion (Bonafede, 1991; De Natale et al, 1991; Gaeta et pyroclastic deposit (Codola formation), dated at about al.; 1998; Castagnolo et al., 2001; Troise et al., 2001). 25,000 yr BP. At least seven Plinian eruptions occurred Moreover, De Natale et al., 1993, 1997, and Troise after the Codola event, 22,500 yr BP (Sarno), 17,000 et al., 1997, have recognized and modeled the main yr BP (Basal ), 15,500 yr BP (Greenish Pumi- structural effects, which explain most of the peculiar ces), 11,400 yr BP (Lagno Amendolare), 7,900 yr BP features of the Campi Flegrei unrest. ( Pumices), 3,550 yr BP (Avellino Pumices) In particular, Gaeta et al. (1998) have developed a and 79 AD ( Pumices) (Fig. 12). model for describing water fl ow in a porous medium under the effect of thermal and pressure gradients, by using experimentally-determined fl uid-dynamical parameters for caldera rocks. The model simulates geothermal system in , thus indicating that the water fl ow in shallow aquifers, under the effect of pressure and/or temperature variations within the geothermal system, can be very important in the ge- nesis and evolution of unrest crises, and in particular, that the water fl ow can strongly amplify the effect of pressure increase in the magma chamber on ground uplift. The cylindrical model, with constant overpres- sure of the order of 10Mpa, can fi t both the magnitude and the shape of the observed total uplift. Eruptions, due to their amplitude and recurrence, to- gether with ground movements and seismic activity, Figure 12 - Isopachs map of Somma Vesuvius plinian, have not only greatly infl uenced human activity in subplinian, and vulcanian eruptions. the past, but have recently presented great problems. The Plinian formations of Somma-Vesuvius include Their understanding and forecasting is a major task fall out units mainly dispersed east of the volcano, due for volcanological research in Italy. to the prevailing direction of the upper stratosphere and throposphere winds, as well as pyroclastic fl ow and surge units emplaced on the volcano fl anks and The Somma-Vesuvius strato-volcano the surrounding plains, up to a distance of ca 15 km from the vent (Fig. 13). 3.1 Volcanological setting According to Delibrias et al. (1979), the Plinian erup- Somma-Vesuvius is emplaced on a regional NE-SW- tions in the last 17,000 years, which occurred after trending fault system, related to the stretching of the centuries to thousands of years of quiescence, repre- lithosphere. It is a composite strato-volcano, consi-

sent the beginning event of eruptive cycles. P55 to PW06 n° 6 - from Volume sting of the old edifi ce of Monte Somma, featuring The last cycle started with the 79 AD eruption, and a summit caldera structure, occupied in its center by continued up to the 1944 eruption. The absence of the younger Vesuvius cone. Only the northern rim of lava fl ows interbedded within the pyroclastic se- the Somma volcano relict is well preserved (with a quences younger than 17,000 on the northern Somma maximum elevation of ca 1130 m), and its southern slope, is the only evidence for a main caldera collapse rim is lowered probably because of multiple caldera dating at 17,000 yr BP. collapses, as well as fl ank collapse, and is buried un- The interplinian activity of the past cycles is poorly

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo eruptions whichoccurredattheendoftens is well-documented,inparticulartheparoxismal lion ofcubicmeter. Mixed effusive-explosive activity few millioncubicmeters,andsomehundredsofmil- magnitudes ofthesingleevents rangingbetweena activity hasbeenbotheffusive andexplosive, with the lastcycle (79 AD to1944 AD), indicatethatthe and 1631 AD eruptions.Detaileddataavailable for Plinian eruptions,aswellafterthe79 AD, 472 AD, the stratigraphybetween Avellino andPompei Major stromboliandepositsarewell-documentedin duct, relatedtomoderateandsmallscaleeruptions. known, duetothescarcesurface diffusion ofthepro- Vesuvius inS.Gennaro Vesuviano NEof Vesuvius. Figure 13-SequenceofpliniandepositsSomma Avellino Pumicesdeposits in theNoladistrict. village andskeletons ofhumanvictimsrecovered inthe Figure 14-Partially-preserved structureofaBronze Age - a1.2mthickbedofmassive, well-sortedashwith - aconsolidatedashlayer(3s); with anunderlyingthinwhitepumicebed(2f); - a1.2mthickmassive, graypumicelapillilayer(3f), fi - thinly-stratifi top: NW fl identifi A typesectionofthe Avellino Pumicesformation clastic fl volcano, consistofalower lapillifall, andupperpyro- a 180°widesector(from West toEast),northofthe 1998) (Fig.14). The eruptive sequencerecognizedin of thiseruptiononhumansettlements(Livadie etal., red inthelastdecades,demonstratestrongimpact Campania. Several archaeologicalfi between theOldandIntermediateBronze Age in The Avellino Plinianeruptionmarkstheboundary a Bronze agecatastrophe 3.3.0 The Avellino Plinianeruption(3550yrBP): 3.3 The lastdevastating events by thedeeperreservoir. of activity (after1805until1944),werefeddirectly hypothesizes thattheeruptive events ofthelastperiod variations throughtimePappalardo etal.,2003, magmas wereerupted.OnthebasisofSr-isotopic and 1944 AD, leucitic-tephritictoleucitic-phonolitic to K-phonoliticmagmas.Finally, between 472 AD BP and79 AD, theeruptionswerefedbyK-tephritic volcanism, before 11,500yearsBP. Between11.5ka trachytic magmaswereeruptedintheoldestperiodof et al.,1998;Marianelli1999).K-basaltictoK- glass inclusiondata(e.g.Belkinetal.,1998;Cioni located atabout4and10km,asdeducedbyfl (HKS) rocks,andconsistedofmulti-depthreservoirs silica undersaturatedpotassic(KS)toultrapotassic The magmaticsystemofSomma-Vesuvius produced 3.2 The magmaticsystem future eruption. 600,000 peoplefromthe18towns, inthecaseofa This planincludesapossibleevacuation ofca nian eruption. vius area,basedonthescenarioof1631subpli- Emergency ManagementPlanfortheSomma Vesu- tological studies,theItalianGovernment adoptedan In 1995,onthebasesofvolcanological andmagma- nian eruption,uptoMarchof1944. short eruptive cycles thatfollowed the1631subpli- ne whitepumicelapilli beds(1s). ank ofSomma,includesfromthebaseto ed inS.Anastasia,atLagno Trocchia, onthe ows andsurge units. ed, massive fi massive ed, ne ashbeds(1s,2s)and ndings, discove- ndings, 27-05-2004, 15:12:06 uid and ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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accretionary lapilli (4s) with a laminated bed in its 3.3.1 The 79 AD eruption: the fi rst chroni- upper part (4s’); cle of a Plinian event - an interstratifi ed sequence of wavy, laminated, fi ne- The study of the 79 AD Vesuvius eruption, and the grained ash and fi ne lapilli beds (5s, 6s, 7s, 8s), and merging of theoretical considerations and fi eld evi- massive coarse, gray pumice lapilli fallout layers (4f, dence, are critical for mitigation of volcanic disasters 5f, 6f, 7f), 10 to 40 cm thick. at Vesuvius and other explosive volcanoes. The dispersion axes of the main fallout units are Volcanological study, consistent with the written oriented NNE consistently with the deposits of the report by Plinius (), indicates that other Plinian eruption of Somma-Vesuvio, thus in- the Plinian eruption started around mid-day on the dicating the effect of the prevailing direction of the 24 August, with a sustained , lasting winds from the western sectors. The dispersion and for 19 hours, which rapidly rose to an elevation of 15 the inferred column heights of the two major Plinian km, and continued to grow to a maximum height of deposits (2f and 3f), are 800 and 1500 km2, and 25 and 32 km. Ash and lapilli, dispersed SSE of the volcano 36 km, respectively. The pyroclastic density currents by the dominant winds, covered the land with up to a (pyroclastic fl ows and surges) deposits are mostly dif- meter thick pyroclastic blanket, that partially buried fused from NNW to NNE of the volcano, over a 500 Pompeii, Stabia, and several Roman villas. km2 inferred area, with a volume of ca. 1 km3. The At least six times in its later phase, the Plinian erup- pyroclastic surge and fl ows sequence, with a maxi- tive column collapsed, generating pyroclastic fl ows mum thickness of about 15 m (on the western volcano and surges, that spread mostly over the southern and slope), has been recognized up to a distance of ca. southwestern slopes of the volcano as gravity-driven 22 km from the vent. The coincidence of the surface currents, thus devastating a wide area. distribution of the surge deposits with the present The fi rst column collapse, ca. 12 hours after the urban area of Naples, indicates the relevance of such beginning of the Plinian phase, formed a surge (S1) types of eruptions in terms of volcanic hazard. In the which overran the town of , and caused last decade, a number of sites buried by the primary hundreds of deaths. The spreading and deposition of and secondary products related to this event have the surges and fl ows were strongly controlled by the been found in the plain and in the surrounding topographic setting of Herculaneum. topographic hills. In particular, the partially preserved structure of Bronze Age villages have been found in 3.3.2 Herculaneum: an impressive record Nola district, and the fi rst two skeletons of the human The town was located ca. 6 kilometers WSW from the victims of this eruption have been found in S.Paolo crater, at the foot of the volcano’s slope, on a dipping Belsito, within the fallout lapilli unit. tuff terrace overhanging the sea, and between two Volume n° 6 - from P55 to PW06 n° 6 - from Volume

Figure 15 - Sketch of the passage and emplacement of the fi rst surge on the waterfront area.

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo Palaeomagnetic analysis oftilesfoundengulfedin pended ontheavailable space(Fig.16). between 15and41individuals, and thecrowding de- died. The numberofvictimsinthechambers,ranging at least300people,takingshelterfromtheeruption, wide, and3.5mdeep),inthesuburban area,where waterfront chambers(onaverage 3.5mhigh, 3.0m A maximumthickening ofsurge S1occurredin12 ge (S2)whichwas emplacedonehourlater(Fig.15). bility, incontrastwiththedevastating subsequentsur- by arelatively low momentum andlow carryingcapa- the fi The lackofstructuraldamage,duetothepassage laminations andpumicelensesappearonlylocally. the defl with athicknessrangingbetween0.2and1m,dueto continuous, fi ness of20m. The fi coupled unitscovers thebasalunitsfor atotalthick- deposit onthewaterfront area. A sequenceoffour and therelatedfl prises thedepositsoffi The basalpyroclastic sequenceatHerculaneumcom- rivers. rst surge (S1),indicatesthatitwas characterized ation ofaturbulent cloud.Low angleinternal ne-grained, massive ashbedemplaced Figure 16-Skeletons ofhumanvictims recovered inthechambers atHerculaneum. ows, whichformeda2to5mtuff rst surge (S1)consistsofanear rst two surges (S1andS2) hand contractions,andpreservation ofbone connec- thermally-induced boneandskullfractures,feet This evidence isconsistentwiththe occurrence of renzo etal.,2001). likely duetoafulminantshocksyndrome(Mastrolo- reaction time,thussuggestinganinstantaneousdeath were inhibitedinatimeshorterthantheconscious reaction oragony. This indicatesthatvitalactivities of death,lackingevidence ofvoluntary selfprotective mechanical impact,appearasif“frozen”intheinstant ge emplacement:theindividuals, allunaffected by stance, whichrefl The skeletons insidethechambersshow alife-like tions ofthepyroclastic fl the volcano, isalsosuggestedbynumericalsimula- temperature, ofca.650°C,atadistance6kmfrom provided bythecarbonizationofwood. Highcloud emplacement temperatureofthepyroclastic surges is emplaced at425°C.Evidenceofaparticularlyhigh surge S2deposit stronglyindicatesthatthisunitwas °C. Analysis of15tilesandbricksintheoverlying 12, apossibleemplacementtemperatureofnear480 gle specimen,collectedattheentranceofchamber surge S1,orlying onthesand,indicatedinonlyasin- ects theoneattimeofsur- ow. 27-05-2004, 15:12:11 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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Figure 17 - Pyroclastic sequence of 472 A.D. Pollena eruption in , north of Vesuvius. The lower unit, consisting of magmatic fallout layers, is topped by the stratifi ed Hydromagmatic sequence.

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo took placeinthecriticalperiodoffall ofthe We- The 472 A.D. PollenaeruptionofSomma-Vesuvius at theendofRomanEmpire 3.3.3 The 472 AD Pollena sub-Plinianeruption: ture (>500°C),andrapidsofttissuevaporization. tions causedfromtheexposure tovery hightempera- caldera. in 103yearsislimitedtowithinthecentralpartof years respectively. Maximumoccurrenceofsomeevents the Somma–Vesuvius inthelast12,000yearsand20,000 of PDCsgeneratingeruptionsinCampiFlegrei,andat the resultsofoursimulationandyearlyoccurrence and asanumberofinferred PDCs.Themapisbasedon yearly probabilityfor each areatobeaffected byPDCs, Flegrei a)andSomma- Vesuvius b)computedasthe Figure 18-Hazardmapfor pyroclasticcurrentsinCampi 27-05-2004, 15:12:17 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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stern , signifi cantly accelerating the ds, characterize the plain north and east of the volca- deterioration of the local human context in the Late no. Debris fl ows are mainly confi ned within Mountain Ancient age. It was an intermediate-scale explosive slopes and in foothill fans. event including pyroclastic fall, surge, and fl ow (Ma- Integrated geological and archaeological strati- strolorenzo et al., 2002). The eruption comprised a graphies, revealed by the new excavations, document pulsating, sustained, eruption column phase, followed the degree of frequentation of the sites at the time of by pyroclastic surges and scoria fl ows; different from the Pollena eruption, the environmental effects of the typical Plinian eruptions of Somma-Vesuvius, primary and secondary events, including damage to hydromagmatism acted early in the event. Specifi c structures, and the recovery time of the terrirory after facies associations of primary and secondary vol- the eruption in the different domains. caniclastic deposits characterize three depositional Some tens of new excavations in a dozen sites relative domains, including the volcano slopes, the surroun- to parts of the Roman towns of Nola and their suburbs ding alluvial plains, and the distal mountains of the and surrounding countrysides, include civil, religious, Apennine Chain (Mastrolorenzo et al., 2002). Both and commercial buildings, villas, amphitheaters, main volcano slopes and distal mountain slopes supplied roads, aqueducts, and other hydraulic works and agri- loose pyroclastic material to the hyperconcentrated cultural work tracks. fl ood and debris fl ows that spread across the alluvial In most of the sites, the Pollena deposits overlie alrea- plains. The great impact of secondary volcaniclastic dy-ruined structures, thus indicating that the area was processes arose from: (1) the high vulnerability of the in a phase of deep decline. In some cases, thin soils territory, due to its geomorphic context; (2) the humid and alluvial deposits pre-dating the Pollena eruption, climatic conditions; (3) the hydromagmatic character cover ruined structures and indicate the abandonment of the eruption; (4) the decline of land management at of the site before the Pollena eruption. the end of the Roman Empire. Direct effects on the people are not documented in the The deposits of the Pollena eruption belong to the chronicles, nor in the excavations, with the notable highest-magnitude eruption which took place at the exception of some tens of human skeletons, which Somma-Vesuvius after 79 A.D. They can be traced have been found within a hardened mud layer dated with remarkably lateral continuity over an area exten- near the end of the V century in the basilicae. ding from the Somma-Vesuvius, through the northern There is evidence that these people died in a cata- and eastern sectors of the Campanian Plain, as far as strophic event – possibly the church roof collapsed the western Apennine Mountains. due to accumulation of lapilli (Pagano, 1997). Four units have been recognized at the type-locality of Pollena, including, from base to top (Fig. 17): 3.4 Modeling of the volcanic hazard in the 1. unit AL: repeated clast-supported, even-parallel, Neapolitan area surface-mantling beds, made up of well-sorted, angu- In order to assess the volcanic hazard in the Neapoli- lar, moderately vesicular, dark gray, scoria lapilli and tan area, a numerical simulation of both concentrated subordinate lava lapilli, indicating an origin by fallout and diluted primary and secondary pyroclastic densi- from an eruption column; ty currents (PDCs) on a digital topographic model of 2. unit SL: alternating scoria fall layers and planar-to- Campi Flegrei and Somma - Vesuvius has been car- cross-laminated ash layers, with traction sedimenta- ried out (Fig. 18, a and b). Families of numerical fl ows tion features indicative of deposition from pyroclastic are generated by sampling a multi-dimensional matrix surges; of vent coordinates, fl ow properties, and dynamical 3. unit S: planar to dune-bedded pyroclastic surge parameters in a wide range of values, which are based deposits; on the current volcanological knowledge (Rossano et 4. unit F: massive, poorly-sorted, matrix-supported al, 1998; Rossano et al, 2003). Hazard maps are con- deposits, containing dark gray scoria and lithic lapilli structed from the data base of simulated fl ows, using P55 to PW06 n° 6 - from Volume and blocks. a mixed deterministic-statistical approach. Results At the top of the primary magmatic deposits, a se- show the key role of the topography in controlling the quence of different types of secondary syn-eruptive fl ow dispersion. The maximum hazard related to the and post-eruptive secondary deposits have been reco- Campi Flegrei eruptions appears to be the NE sector gnized. Extrusive mud fl ow deposits and laminated of the caldera. Flows in the western sector, including beds, related to hyperconcentrated currents and fl oo- the city of Naples, are shown to be effi ciently hinde-

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo ra, Pozzuoli,(Naples). Risorta (Caserta,)andwithintheCampiFlegrei Calde- Garigliano River, ca.80kmnorthofNaples, inCalvi pyroclastic depositswillbeshown inthe sitesofthe Flegrei. Distaland proximalsectionsofthemajor and older(>12ka)eruptive sequencesofCampi Large IgnimbritedepositsofCampanian Field itinerary from pyroclastic fl present thefi PDCs ineachpoint,arealsoprovided. The resultsre- cano. Dynamicoverpressures, relatedto the passageof mainly constrainedwithinabout15kmfromthevol- The hazardrelatedtotheSomma-Vesuvius PDCsis hills atthecalderaborders,thusreducinghazard. red bythepresenceofPosillipoandCamaldoli rst physically-basedestimationofhazard ows inthisdensely-populated area. DAY 1 Figure 19-Locationsofthefi its originfromadilutepyroclastic densitycurrent; with anearlyhorizontaluppersurface, thusindicating Calvi Risorta,thedepositinfi proximal facies. BothintheGariglianoRiver, andin black juvenile scorias areaslarge asabout1minthe the extreme distalevolution oftheCI.Infact, the the structureandgrainsizeofdepositrepresent of glassshardsandvery rarecrystalsandlithics.Both tered withintheashymatrix,whichmostlyconsists the hotdeposits.Fine,blackvesicular scoriaarescat- the jointingindicatenon-homogeneouscontractionof ting (Fig.20).Inparticularzones,theconvergence of changes inthesizesandgeometryofcolumnarjoin- and themainfeaturesofdepositarelocal mns). Novertical gradingorstratifi with columnarjointing(10to20cmprismaticcolu- consist ofaca10mthickfi Distal facies ofCampanianIgnimbriteinthesesites Calvi RisortaandtheGariglianoRiver Stop 1and2: eld tripstops lls thetopographic lows ne-grained weldedtuff, cation ispresent, 27-05-2004, 15:12:23 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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Figure 20 - Columnar jointing in the Campanian Ignimbrite formation. however, the absence of evidence of the erosion of the two most conspicuous deposits. Both are emplaced, underlying pre-existing ground surface, is consistent as relatively concentrated pyroclastic density currents with a gentle emplacement for en-mass freezing of an expanded” pyroclastic cloud (Fig. 21). Stop3 and 4: Torregaveta and Acquamorta Beach, Monte di Procida (SW Campi Flegrei cadera rim) The Torregaveta marine cliff, on the southwestern Campi Flegrei caldera rim, exhibits an extended eruptive sequence, including the pre-caldera lava domes and pyroclastic deposits, Museum Breccia and post-caldera pyroclastic sequence (Fig. 22). From the base to the top, the following units are exposed: 1) pre-caldera trachytic lava domes; 2) pre-caldera stra- tifi ed pyroclastic surge and Strombolian sequence, 3) P55 to PW06 n° 6 - from Volume Museum Breccia, 4) post-caldera deposits, including Torregaveta tuff breccia, and 5) Neapolitan Yellow Tuff. An unconformity defi nes the stratigraphic re- lationship between the Neapolitan Yellow Tuff at the top of the sequence, and the older volcanic sequence. Breccia Museo and Neapolitan Yellow Tuff are the Figure 21 - Distribution of Campanian Ignimbrite deposits.

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Volume n° 6 - from P55 to PW06 P67 - P67 Strombolian depositsandNeapolitan Yellow Tuff. and Stromboliandeposits,BrecciaMuseo,Torregaveta, Figure 22-Torregaveta cliff sequenceofprecalderasurge Leader: G.Mastrolorenzo are thefi evidence ofa40mprehistoricrapid upliftrelatedto La StarzaterraceinPozzuoli(8,000to4,500yrB.P.) (from 10,000yrB.P. topresent). volcano-tectonic events inCampiFlegrei caldera Neapolitan yellow Tuff andrecent volcanic and dimentary rocks.Breadcrustbombsareabundant. and lithiclava blocks,aswellsubvulcanic andse- pyroclastic fl tly stratifi Museo ismassive andungradedatthebase,fain- which isdescribedintheprevious stop. The Breccia section ofthepre-calderaandpost-calderasequence, south of Torregaveta, presentsavertical stratigraphic The coastof Acquamorta, aca.2kmlongmarinecliff area. the morphologicalandvolcano-tectonic settingofthe rst events responsibleforthemodifi ed attop,andconsistsofaclast-supported ow deposit,containingpumicescoria DAY 2 cation of evolution oftheterritory. the destructionof Tripergole village,andtherelated storical pyroclastic coneofMonteNuovo (Pozzuoli), bour, Serapismarketplace, Villas). The hi- submergence, Baiaimperialvillas,PortusJuliushar- uplift oftheCaldera(CapoMisenotuff coneandits rect evidence ofgroundsubsidenceandepisodicrapid constructions aroundPozzuoliBay(Pozzuoli)aredi- Averno tuff rings).Onlandand submerged Roman and Nisidatuff cones,andSolfatara, Astroni, and canoes nearPozzuoli(CapoMiseno,Porto history, andmythologyoftheyoungpyroclastic vol- pi Flegrei caldera.Stratigraphy, eruptive mechanisms, the peaksinvolcanic activity inthecenterofCam- bmerged volcanic edifi a well-preserved tuff conebuilt uponpre-existing su- small island(about600m)ofNisidaisconstituted man tunnelof Trentaremi whichcrossesthehill. The outcrops ofPosillipohill(Fig.24),andinsidetheRo- long inclineddunestructures,recognizableonthe slope, thusdepositingvery impressive tensofmeter caused thepyroclastic cloudtoclimbontoasteep consisting ofacoarse-grainedpumicelapillibed,that posit isemplacedonanoldertuff coneof Trentaremi, and anuppermassive induratefi Each thick,coarse-grainedbedisdelimitedbyalower discontinuous bedsandmassive, even fi ganized, matrix-supportedlayers,thinly-laminated wavy-to-planar alternations ofcoarse-grained,disor- quence consistsofaca160mthick,crudely-stratifi of theNYT(Fig.23)formationoccurs. The tuff se- At thePosilliposectionlithifi lipo hillandNisida(West ofNaples) Neapolitan Yellow tuffandNisidaCone:Posil- Stratigraphy anddepositionalstructures ofthe Stop 1: Figure 23-Surfacedistribution ofNeapolitan Yellow Tuff ces. The productsaremadeof along thecalderaborders. ne ashbed. The de- ed uppermember ne ashlayers. 27-05-2004, 15:12:28 ed, ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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Figure 24 - The structures of Neapolitan Yellow Tuff on the walls of the Roman tunnel of the Seiano, crossing Posillipo Hill. stratifi ed yellow tuff, formed by highly lithifi ed beds sgressions of the sea, that occurred between 8,400 to of ashes and pumices, containing abundant scoriae 4,050 yrs ago. The carbon-14 age for a shell recovered and bombs up to 50 cm in size near the crater. from the uppermost marine layer has an age of 5,345+ Roman buildings and structures submerged at about 5 150 yr (Rosi and Sbrana 1987). The positions of m below sea level in this part of the coast testify to the these marine layers, tens of meters above present sea general subsidence affecting the entire caldera since level, cannot be explained solely by eustatic sea level ancient times. Due to its rapid decreasing from the changes during the past 8,000 yrs. The uppermost and center of the caldera, the positive bradyseism effected only subordinately the western and eastern margins of the caldera where the subsidence prevails.

Stop 2: P55 to PW06 n° 6 - from Volume La Starza marine terrace La Starza sea-cliff parallels the north coastline of Pozzuoli Bay from Monte Nuovo to Pozzuoli, and presents three marine layers separated by tephra layers erupted from Campi Flegrei (Fig. 25). The ra- diocarbon ages of the tephra layers indicate that these marine layers were formed during three separate tran- Figure 25 - Sequence of marine and pyroclastic deposits.

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo and Mastrolorenzo,1991). affected bybradyseismintherecenttime.(Dvorak with themostactive centralpartofthecaldera,also in CampiFlegrei. However, thisstructurecoincides ago, betweentwo majorphasesofvolcanic activity ring alongquiescentperiod,from8,000to4,500yrs less than3,000yrs.Mostofthisupliftoccurreddu- youngest marinelayerwas upliftedatleast40min fl an older, mosaicfl to drainstagnantwater, Niccolini(1845)discovered channel. In1822,whileattemptingtoclearachannel for drainageofrainwater throughanunderground marble blocksthatslopetowards thesea,designed The presentfl spring atthissitewas usedaspartofaRomanbath. ced alongtheinternalwalls, suggestingthatthewarm in thebackcornersofmonumenthave seatspla- inside andoutsideofthemonument. Two large rooms a seriesofsmallrooms,whichalternatelyopentothe on theseaward sideandleadsintoaplazaoutlinedby 1st centuryB.C. The mainentrancetoSerapisopens gests thatthismonumentwas establishedbeforethe The lackofopusreticulatuminthefoundationsug- thin, adobebricksandmortar)covered bymarble. m), enclosedbyawall ofopuslateritium(built of monument isroughlyrectangularinshape(70by55 lowing descriptionofthemonument:“Theexcavated Dvorak andMastrolorenzo(1991)reportedthefol- the centerofPozzuolitown. reconstruction ofthetimeevolution ofgroundlevel at by Dvorak andMastrolorenzo(1991),whodefi grei. These studies have beenintegrated andupdated history ofseculargroundmovements atCampiFle- dola (1947),fi cording ancientrelative sealevel changes.Parascan- left shellsintoitsthreestandingmarblecolumns,re- mollusc, Lithodomuslithophagushasboredintoand 1872; Gunther, 1903;Parascandola, 1947). A marine 1829; Niccolini,1839,1845;Babbage,1847;Lyell, after itsexcavation in1750(Breislak,1792;Forbes, been theobjectofmuchresearch,beginning shortly most studiedarchaeologicalsite. The monumenthas large, seculardeformations.Serapis Temple isthe Roman coastalruins,whichweremoresensitive to came fromtheobservation ofsealevel markers on The fi and Serapeo Ancient andmodern town ofPozzuoli Stop 3: oor. At thecenterofmonumentisarotunda,whi- rst studiesofslow movements atCampiFlegrei oor ofthemonumentiscon-structed rstly delineated,usingthesetracks,the oor 2.1mbelow thepresentmarble ned a ned ch rises1.2mabove themarblefl The detailedreconstructionofthegroundmovement also have served asaRomanthermalbath.” of backcornerroomssuggestthatthisstructuremay niche onthebackofSerapis,andseatsalongwalls the centralrotundainfrontoflarge semi-circular standing marblecolumnsarelocatednortheastof also constructedduringthe2ndcentury. The three opus latericiumandcov-ered withmarble,probably (Levi, 1969),andthefoundationwalls, constructedof probably constructedinthemid-2ndcenturyB.C. lies 2.1mbelow thepresentmarblefl date fromthisoriginalusearethemosaicfl a temple. The partsof themon-umentthatprobably 1979). The original Romanbuilding mayhave been 1820; Nicco-lini,1845;Parascandola, 1947;Sicardi, three mainusesduringtheRoman Age (DeJorio, its architectureandlocation,Serapisprobablyhad standing columnroseabove groundlevel. Basedon excavation in1750,onlythetopfew metersofeach upper halfofeachstandingcolumn. At thetimeof the seadid,laterdepositscovered and protected the either becausesealevel never reachedthemor, if they, too,werenever indirectcontactwithseawater, columns werespareddamagebymollusksbecause with seawater. The upper6-m-longsectionsofthese by debris,andmaynever have beenindirectcontact mollusks becausetheselower sectionswerecovered The lower 4-m-longsectionswerespareddamageby must have beenimmersedinseawater foralongtime. the 3-mperforatedsectiononeachstandingcolumn of penetration,andtheextent oftheseperforations, shells remainonthesecolumns.Becauseofthedepth as asouvenir oftheirvisit(Lyell, 1872). Today, no monument duringthe19thcenturyextracted shells rock andbuilding ashellcasing.Many touriststothis itself justbelow theseasurface byboringintosoft side themarble(Forbes, 1829). This molluskattaches that hasboredinandleftshellsas5deep0.1min- ted allaroundbyamollusk,Lithodomuslithophagus, next 3msectiononeachstandingcolumnisperfora- height ofabout4mabove thefl surface ofeachcolumnissmoothandunbroken toa the mostremarkablefeatureofthismon-ument: main piecesonthefl columns arestillstand-ing;thefourthliesinfour of asolidpiececipolinomarble. Three ofthese 13 mhighand1.5indiameter, eachconstructed forms partofthebackwall, werefourlarge columns- of themonument,infrontasemi-circularnichethat by 5-m-highcolumnscutfromgranite.Neartheback oor. The standingcolumnshold oor; thesurface ofthe oor andwas outlined oor, andwas oor, which 27-05-2004, 15:12:35 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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at Serapis is poorly constrained; however, Parascan- a part of which has been lithifi ed by post-depositional dola (1947), and Dvorak and Mastrolorenzo (1991), mineralization (zeolitization). have described the main events on the basis of histo- The second unit (II) crops out around the whole rical reports and inferences. On this basis, the Authors volcano, and with an inferred maximum thickness of 60-70 meters, forms the major part of the cone. Largely unlithifi ed, it has a textural appearance si- milar to unit I. The bulk of the deposit consists of an essentially chaotic arrangement of lithic fragments of lava and yellow tuff, up to about 10 cm across and rounded pumice set in a matrix of coarse ash. Close to the vent, however, a weak undulatory banding is apparent, owing to the arrangement of zones rich in large pumice fragments 30 cm or less in diameter. Sparse fragments of jars, scattered within the I and II units, likely derive from the Tripergole village, buried by the eruption.

Figure 26 - History of vertical movement at Serapis. Extrapolation of a subsidence rate of 14mm/yr, suggests that the fl oor of the Serapis may have been about 4 m above sea level after the 1538 eruption in Campi Flegrei. If Serapis reached its maximum subsidence of 7 m below sea level during the 15th century, then uplift of about 11m occurred during the fi rst few decades before the 1538 eruption in Campi Flegrei. Based on eyewitness accounts, uplift of a few meters occurred the two days immediately before the eruption. A constant subsidence rate of 11mm/yr can account for our estimate of 5 to 10 m for the original elevation of the tiled marble fl oor of Serapis. (Dvorak and Mastrolorenzo, 1991)

have found a general trend characterized by a constant rate of subsidence (11 to 14 mm/yr), interrupted by short time episodes of fast ground uplift (Fig. 26). (Tab.1,2,3) Stop 4: Monte Nuovo pyroclastic cone The deposits of the Monte Nuovo eruption cover an area of some 3.6 km2, with a dense-rock equivalent volume of about 0.025 km3. Four depositional units have been recognized by Di Vito et al, (1987) (Fig. 27).

The fi rst unit (I) is exposed in outcrops around the P55 to PW06 n° 6 - from Volume southern part of the volcano, with a maximum thick- ness of about seven meters (Fig. 28). It has a general- ly chaotic textural appearance, with an abundant ashy matrix containing fragments of poorly vesicular and sub-rounded pumice clasts ,and non-juvenile lava and yellow tuff fragments. Welding, pipe structures, and evidence of plastic deformation are absent in this unit, Table 1 - (from Dvorak and Mastrolorenzo, 1991)

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo The thirdunit(III),covers mostof theouterfl unit andanupperstratifi (Mastrolorenzo, 1994):alower coarse-grained fallout Averno maarconsistsoftwo mainlithologicalunits Averno maar Stop 5: of weldingorplasticdeformation. scoria arecoarseandangular, andshow noevidence scoria separatedbyathin,irregular layersofash. The meters atitsmargins. It consistsoftwo layersofblack tersl andvaries inthicknessfromamaximumof25 section, itpinchesoutlaterallyover afew tensofme- below thecraterrim(Fig.28).Inatransverse cross pression onthesouthernouterslopeofvolcano, The fourthunit(IV),isconfi derately vesicular pumice. juvenile material,andoccasionalpiecesofpale,mo- black scoria,containingangularfragmentsofdenser massive grayashbedsandwichedbetweenlayersof towards itsbase. Three layersmaybedistinguished, meters nearthetopofcone,tolessthanone tion aroundthevent, thedepositthinsfromabout3-2 the maincone. With arelatively even radialdistribu- (from Dvorak andMastrolorenzo, 1991) Table 2-Horizontalextentandcausesofvertical movement nearNaplesbay, southernItaly ed pyroclastic surge unit ned withinasmallde- anks of Figure 27-Distribution oftheproducts of theMt.Nuovo eruption. 27-05-2004, 15:12:39 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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Figure 28 - First hydromagmatic unit of Monte Nuovo (left) and fi nal IV unit scoria deposit (right).

(Fig. 29 and 30). The lower unit com- prises an alternation of grain-supported fallout lapilli tuff with abundant lithic blocks (mainly in the proximal outcrops and in the basal part), and subordinate fi ne-grained, wavy-to-massive wet surge bedsets. The fallout layers consist of juve- nile angular trachytic pumice lapilli, more dense scoriaceous lapilli, and bombs as well as rounded, yellow tuff blocks and trachyte lithics blocks derived from the underlying volcanic deposits. The upper units consist of wavy-to-planar fi ne ash bedsets, containing continuous laminae of matrix-supported, fi ne, rounded pumice lapilli. Crater wall section: On the crater wall, the lower unit is a 10 m thick sequence, consisting of ungraded to normal graded, coarse lapilli and block fallout layers, interbedded with discontinuous matrix supported beds, containing rare pumice lapilli and large ballistic lithic blocks. The Figure 29 - Schematic stratigraphic section largest blocks exceed 0.5 m in diameter through a most complete exposure at the base of the lower unit, and form a of the two main units and associated facies on the north eastern outer tuff ring slope. large impact structured on the paleosol. Lithological symbols: 1, Palaeosoil dated at 3,700 years BP; The upper unit is exposed on the northern 2, open framework, grain-supported, well-sorted pumice lapilli layers, inner crater wall, with a thickness ranging with tuff blocks and scoriaceous bombs (fallout deposits); between about 25 and 50 m, depending on 3, massive, poorly-sorted, matrix-supported beds forming the fi rst the morphology of the older tuff relicts. hydromagmatic episodes; 4, continuous, massive, The unit is poorly-sorted and nearly struc- moderately-to-highly cohesive, very fi ne ash tureless at the base, becoming fi ner and and accretionary lapilli beds intercalated with the fallout layers; 5, discontinous laminated ash and fi ne better stratifi ed upsection. At the top, the P55 to PW06 n° 6 - from Volume rounded lapilli bedsets; 6, fi ne grained cross-bedded unit consists of alternating centimeter sca- to waved bedsets with accretive lapilli le ash beds and rounded lapilli layers. (the main wet pyroclastic surge deposits of the lower unit); North-eastern outer crater section: The 7, waved-to-planar, thick bedset of fi nely-stratifi ed lower unit shows a better defi ned strati- ash layers with accretive lapilli of the upper unit; fi cation, comprising at least fi ve thinner, and 8, post-eruptive reworked layers fi ner and better sorted fallout layers, and (Mastrolorenzo, 1994) relatively thicker intercalated fi ne beds,

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo racterized bythepresenceofirregular millimeter-si- bedsets. Thin induratebedsofvesiculated tuff, cha- pisolitic ashbedsdrapesomeofthepyroclastic surge tain accretionarylapilli.Continuous,2-50cmthick which exhibit dune-type cross-stratifi Table 3-HistoryofthePozzuoli areaandevidencefor vertical movements (fromDvorak andMastrolorenzo, 1991) cation, andcon- wavy andcross-bedded-to-planarfacies (Fig.31). changes: thefi section, theupperunitthinsandshows lateralfacies zed cavities, occuratdifferent levels. Intheouterrim ne ashbedsetschangefromlow angle 27-05-2004, 15:12:44 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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constructed between the 1st century BC and the 2nd century AD. The last pier of the Roman breakwater lies about 800 m from shore. An attempt was made in 1959 to map the underwater ruins at Baia systemati- cally. Based on maps published in Lamboglia (1959), the landward end of the Roman breakwater is at a dep- th of about 10 m. Roadways built of individual paving stones, some with ruts made by wagon wheels, and doorways leading into buildings and courtyards, are common at depths shallower than 7 m. The deepest feature was a straight channel, probably for drainage, several meters long, about 0.1 m wide, and 0.15 m Figure 30 - Isopach maps of the lower fallout unit and deep, at a depth of 8 m, and located near the landward the upper surge unit. The Control of the topography on end of the Roman breakwater. The deepest Roman the emplacement of the pyroclastic surge is evidenced by stonework on the surviving piers of the breakwater is the change of ashy sequence thickness, mostly near the at a depth of 18 m. southern and western hilly areas. The deposit thickness is expressed in meters (Mastrolorenzo,1994) Stop 7: Miseno tuff cone. The Roman thermal area Stop 6: and villas. The submerged town of Baia Capo Miseno tuff is the relict of a stratifi ed and A detailed description of the submerged Town of Baia very highly lithifi ed tuff cone (Figs. 32 and 33). The is reported by Dvorak and Mastrolorenzo (1991), that tuff, yellow in color, is formed by inclined layers of suggests a net subsidence of about 8 m since Roman pumice/lapilli in an altered ashy matrix, with a mas- times. Extensive use of opus reticulatum in wall con- sive planar and cross-laminated structure. struction at this site indicates that most of the city was Part of the crater is preserved only to the west, whi- Volume n° 6 - from P55 to PW06 n° 6 - from Volume

Figure 31 - Alternation of the stratifi ed fi ne ash surge beds and fallout layers of Averno, north of the crater.

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo navy fl crater was theHarbourofPliny theElder’s Roman tuff ringfeaturingastratifi Porto Misenovolcano, whichisarelictoflow rim (visible fromthesea).EastofcapoMiseno,thereis convergence betweentheinnerandoutercraterslopes volcano slope. The lighthouseislocatednearthe le thenorthernslopeisasmallsectorofouter crater slopestratifi Cone cliff, attheintersectionbetween innerandouter Figure 32-TheCapoMisenolighthouseatthetopTuff eet. Figure 33-SubmergenceoftheRomangrottosonbeach onthenorthwestern coastofCapoMiseno. cations. ed yellow tuff. The wide lapilli bed(unit1fb)gradingupwards toawhitepu- m thickinversely gradeddarkgraylithicandpumice basal homogeneousmassive thinash-layer;2)a0.6 the top,following unitshave beenidentifi column ofthefi mostly magmaticepisodesrelatedtothesubstained fi top, alower anduppermemberhave beenidenti- and massive surge sequence.Fromthebaseto This basalsequenceistoppedbyathickstratifi breccia andpumice-lapillifallout units(Fig.35). opening phaseoftheeruption,consistingcoarse the baseofsequencecropoutdeposits phreatomagmatic phasesofthiseruption(Fig.34). At posits relatedtotheinitialmagmaticandfollowing Plinian eruption(3550yrsBP),includingallthede- crops outthemostproximalsectionof Avellino In theNovelle quarry(W-NWofSomma-Vesuvius) Proximal faciesof Avellino Plinianformation Stop 1: tions ofSomma-Vesuvius Avellino PlinianandPollena subplinian forma- ed. The lower memberincludesthedepositsof rst Plinianphase.Fromthebaseto DAY 3 27-05-2004, 15:12:48 ed:1) a ed:1) ed ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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mice lapilli layer (1f); 3) a ca. 1.8 m thick sequence of a massive layer, consisting of coarse lapilli and block in a fi ne ash matrix, interbedded with fi ne ash units; 4) a 0.6 m thick white pumice lapilli fallout bed with dispersed blocks (2f white pumice unit); 5) a 2 m thick massive moderate-to-poorly sorted gray pumice lapilli and block fallout layers, with interbedded ash and sand layers (3f gray pumice unit). The upper member includes the deposits of the second phase of the eruption, deriving from a Plinian column collapse, which follows the climatic phase of the eruption (Fig. 36). From the base to the top, the following units have been identifi ed : 1) a massive coarse-grained lapilli and block pyroclastic fl ow deposits; 2) ca. 10 m thick stratifi ed and massive pyroclastic surge ash and lapilli beds (units from 3s to 8s); 3) the fi ne-grained thickly bedded deposits, consisting of undulatory waved bedsets with cross-laminations. Climbing dunes are present mostly in the middle of the sequen- ce where intense erosional episodes took place. Massive poorly-sorted lenses, related to leeside and stooside (?) accumulation of lapilli and blocks, resulted from the erosio- nal effects of the more violent surges on the fallout beds. Stop 2: The crater of Vesuvius The present Vesuvius crater results from the effusive and explosive eruptions occurring in the last few centuries. In particular, in the upper part of the crater, the contact between the 1906 and 1944 crater structures is expo- sed. From the crater rim of Vesuvius, a view of the summit area of the Somma-Vesuvius volcano, the Somma caldera, the most re- cent 1944 lava fl ows and small scale hot debris avalanches is allowed. Volume n° 6 - from P55 to PW06 n° 6 - from Volume

Figure 34 - Stratigraphic section of the Avelliono Plinian eruption at Lagno di Trocchia near S.Anastasia. (Rolandi et al., 1993)

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo Avellino basesurgedeposits.(Rolandietal.,1993) Figure 36-Isopach mapandfaciesdistribution ofthe member 3f. (Rolandietal.,1993) of theplinianpumicedeposit2f;andgray the basalthinlayer1farerepresented;whitemember formation. Thetwo majorair-falllayerswhich overlie Figure 35-Isopach mapsofthefallout Avellino of Nola.(fromMastrolorenzoetal.,2002) Figure 37-First centuryBCRomanamphitheater by youngerpaleosoils. section, withanaverage thicknessofca4m,istopped massive, highmatrix-strengthdebrisfl fl brownish-gray, massive ungraded,cohesive debris eruption columninterbeddedwithashlayers,2) recognized: 1)scoriafallout, fromasub-stained 38). Fromthebasetotop,two unitshave been and secondarydepositsofthe472 AD eruption(Fig. between 1996and2001,was buried bytheprimary Nola Roman Amphitheatre (Fig.37),excavated excavations. of theshallow stratigraphicsequenceexposed inthe (472 AD), arerecognizableinthefi (7900 yrsBP), Avellino (3550yrsBP),andPollena fl interbedded withsecondarydebrisfl In particularthepyroclastic fallout andsurge deposits eruptions of Vesuvius. fected byprimaryandsecondarydepositsofvarious age, duetoitsposition,theNolaareahasbeenaf- of theCampanian Apennine. Sincetheprehistoric east andnorthbytheMesozoiccarbonatemountains the alluvialplainnorthof Vesuvius, surroundedtothe The town ofNola,15kmfrom Vesuvius, islocatedin amphiteatre atNola The Pollena (472 AD) eruption andtheRoman Stop 3: ow deposits;3)brownish-gray, matrix-supported, ood depositsrelatedtotheeruptionofOttaviano tigraphy, arealsodocu- and volcanological stra- the detailedarcheological struction ofthesites,and two events. The recon- the sitesaffected bythese eruptions, collectedfrom the Avellino and472 AD to thetimeinterval between of thefi of theNoladistricts.Most the stratigraphicsequence diaeval agefoundwithin ted fromprehistorictome- collections offi seum ofNolapreserves The archaeologicalMu- Museum ofNola. The archaeological Stop 4: mented. ndings arerelative rst few meters ow laharsand ow. The whole nig da- ndings 27-05-2004, 15:12:55 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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DAY 4 The 79 A.D. Plinian eruption of Vesuvius: the volcanic stratigraphy and effects on people and structures in Herculaneum, Oplonti, and Pompeii an Stabia (SE of Naples). Stop 1: The Roman town of Figure 39 a and b - Stratigraphy of the A.D. 79 volcanic Herculaneum deposits on Herculaneum beach. The archeological excavations of the Roman town of Herculaneum which was buried by the 79 AD contrast with the fi rst surge, which does not includes pyroclastic fl ow and surge, is revealed under the stra- coarse fragments, the second pyroclastic surge is rich tigraphy of pyroclastic units, and shows the effects of in blocks, tiles, bricks, columns, and wall fragments, the emplacement on the structures of objects and peo- deriving from the buildings demolition thus sugge- ple (Fig. 39 and 41). A ca. 20 m thick pyroclastic tuff sting a high dynamic overpressure of the pyroclastic deposit, exposed on the southern side of the excava- cloud. Groups of tens of skeletons are still present in tion, exhibits the products of the some of the chambers, on the fl oor a few cm above the entire eruptive episode following chamber fl oor imbedded within the ashy fi rst surge. the climatic phase of the Plinian sustained column. Relatively thin, Stop 2: mostly fi ne-grained horizontal The of Oplonti pyroclastic surges are alternated The Roman villa of , discovered in 1967 near with thick, massive, coarse ma- the , south of Vesuvius, is one of the trix-supported pyroclastic fl ow most complete sites for the study of the entire deposi- units. The base of the sequence tional sequence of the 79 A.D. plinia eruption (Figs 42 coincides with the level of the and 43). The ca. 5 m thick stratigraphic section, expo- ancient coast line. From the base sed within the excavations, comprise all the lapilli fall to the top, S1 to S6 surges alter- out units, the interbedded pyroclastic surge, and the nating with F1 to F6 pyroclastic upper pyroclastic surge and fl ow units. The evidence fl ows, are exposed (Fig. 40). At of roof and wall collapse, due to the accumulation of the base of the sequence, directly fallout lapilli, as well as the effects of the impact of overlying the older tuff substra- pyroclastic fl ows and surge on buildings and trees, are tum of the Roman beach, crops well preserved in the site. out the 20 to 90 cm thick ashy, massive cohesive fi rst surge (S1). Stop 3: This layer fi lls twelve water front Pompeii chambers, where ca two hundred The excavation of the Roman town of Pompeii has skeletons were found. This ashy revealed the most conspicuous evidence of the effects layer is topped by a ca 1 m thick, of the devastating 79 A.D. Plinian eruption (Fig. 44). coarse, fi ne-depleted second sur- Roofs and wall collapses associated with the fi rst pha- ge (S2) deposit. In some places, se of lapilli fall, and to the passage of dilute (surge) between the two layers, the mas- and concentrate (fl ow) pyroclastic density current sive fi rst pyroclastic fl ow deposit are evident. The recently excavated house of Casti is interbedded. The second surge Amanti, facing the Via dell’Abbondanza (the main (S2 ), is overtopped by ca 3 m road of Pompeii), presents a complete assortment of thick matrix-supported, strongly the effects caused by the fall out and pyroclastic surge Volume n° 6 - from P55 to PW06 n° 6 - from Volume cohesive pyroclastic fl ow (F2). In and fl ows on the structure and animals. The pyrocla- stic sequence exposed outside and inside the house, Figure 38 - Stratigraphic section consist of the alternation of pumice lapilli beds, and of the primary deposits of the 472 AD Pollena eruption. The planar and stratifi ed undulatory fi ne-grained surge sequence is topped by the secondary beds. Evidence of wall failures and collapses, likely deposits (debris fl ows, high particle caused by earthquakes occurred before and during the concentrated current) from eruption, have been also recognized. Mastrolorenzo et al., 2002

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo and surgeatHerculaneum. Figure 41-Stratigraphyofthepyroclasticfl Figure 40-TheRomantown ofHerculaneum,with Vesuvius inthebackground. ow ow 27-05-2004, 15:13:01 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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Figure 44 - Stratigraphic sections of the A.D.79 deposit near Pompeii, showing the variation in the deposit Figure 42 - Stratigraphic section of the A.D. 79 between a section at the Herculaneum Gate, northwest of deposit at Oplonti. Note the pyroclastic fl ow the city, and at the Necropolis, southeast of the city. Also layers on top of S-5 and S-6. Thin, cohesive, shown is the variation of maximum diameter of pumice ashy surge at top of the fallout deposit. (red), and lithics (blue) in the fall deposits. (Sigurdsson et (Sigurdsson et al., 1985) al., 1985)

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo Ignimbrite: amajorprehistoriceruptionintheNea- tore, T. andSantacroce,R.,(1978). The Campanian Barberi, F., Innocenti,F., Lirer, L.,Munno,R.,Pesca- area. Bull. Volcanol., 47:175-185. nicle ofavolcano emergency inadenselypopulated G., (1984).Phlegrean Fields1982-1984;Briefchro- Barberi, F., Corrado,G.,Innocenti,F., and Luongo, Volcanol. Geotherm.Res.,48(1/2):33-49. in lightofvolcanological andgeophysicaldata.J. (1991). Structuralevolution ofCampiFlegrei Caldera Barberi, F., Cassano,E.,La Torre, P. andSbrana, A., John E. Taylor, 34p. Searpis atPozzuolinearNaples.London,Richardand Babbage, C.,(1897).Observations onthe Temple of Region, Italy. JPetrol13(3):425-456. rich lavas fromtheRoccamonfi Appleton, J.D.,(1972).Petrogenesisofpotassium- References n ocn, Roman Volcano, na Bonafede M.,(1991).Hotfl Res, 82,79-95. Vesuvius lavas (pre-AD1631).J.Volcanol. Geotherm. chemistry, andmicrothermometry ofinterplinian (1998): Pre-eruptive volatile content,melt-inclusion Belkin, H.E.,De Vivo, B., Torok, K.and Webster, J.D. nic province, Italy. Lithos,26,191-221. Petrogenesis andtectonicsettingoftheRoman Volca- Beccaluva, L.,DiGirolamo,P. andSerri,G.(1991): 41 (1):1-22. politan area(Italy).Bull. Volcanol., Castagnolo, D.,Gaeta,F.S., DeNatale,G.,Peluso,F., du crateredelaSolfatare. Naples,Giaccio170-177 fatare dePuzzole:Part 3,Observatoons surl’exterieur Breislak, S.,(1792).EssaismineralogiquessurlaSol- Geother. Res48:187-198. the 1982-1985crisisatCampiFlegrei, Italy. J. Volc. cient sourceofgrounddeformation. Application to uid migration:aneffi sequence. and fallout surges, basal, Pyroclastic site ofOplonti. Archeological sequence inthe A.D. pyroclastic Figure 43-79 27-05-2004, 15:13:11 - ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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Mastrolorenzo, G., Troise, C., Pingue, F., Mita., G. De Natale, G. Mastrolorenzo, G. Pingue, F Scarpa, F. (2001). Campi Flegrei unrest episodes and possible (1993). I Campi Flegrei e i fenomeni bradisismici. Le evolution towards critical phenomena. J. Volcanology Scienze, 306 feb.1994. and Geotherm. Res 109: 13-40 De Vivo B, Rolandi G., Gans P. B., Calvert A., Bohr- Cinque, A., Rolandi, G., and Zamparelli, V., (1985). son W. A., Spera F. J., Belkin H. E. (2001). New L’estensione dei depositi marini olocenici nei Campi constraints on the pyroclastic eruptive history of the Flegrei in relazione alla vulcano-tettonica. Bollettino Campanian volcanic Plain (Italy). Mineralogy and di Geologia Italia, 104:327-348. Petrology, 73, 1-3: 47 – 65. Cioni, R., Marianelli, P. and Santacroce, R. (1998): De’ Gennaro, M., Gialanella, P.R., Incoronato, A., Thermal and compositional evolution of the shallow Mastrolorenzo, G., and Naimo, D., (1996). Palaeoma- magma chambers of Vesuvius, evidence from pyroxe- gnetic controls on the emplacement of the Neapolitan ne phenocrysts and melt inclusions. J. Geophys. Res., Yellow Tuff (Campi Flegrei, ). From 103, 18,277-18,294. Morris, A. & Tarling, D.H.(eds), Palaeomagnetism Civetta L., Orsi G., Pappalardo L., Fisher R.V., and Tectonics of the Mediterranean Region, Geologi- Heiken G., Ort M. (1997). Geochemical zoning, min- cal Society Special Publication 105: 359-365. gling, eruptive dynamics and depositional processes de’ Gennaro, M., Incoronato, A., Mastrolorenzo, - The Campanian Ignimbrite, Campi Flegrei caldera, G., Adabbo, MR., Spina, G., (2000). Depositional Italy. J Volcanol Geotherm Res 75: 183-219 Mechanisms and alteration processes in different Cole, P.D. and Scarpati, C., (1993). A facies interpre- types of pyroclastic deposits in Campi Flegrei vol- tation of the eruption and emplacement mechanisms canic fi eld (Southern Italy). J. Volcanol. Geotherm. of the upper part of the Neapolitan Yellow Tuff, Cam- Res. 82 , 113-137 pi Flegrei Southern Italy. Bull. Volc.55, 343:356. Deino, A.L., Courtis, G. H., and Rosi, M.,1992. 40Ar/ Corrado, G., Guerra, I., Lo Bascio, A., Luongo, 39Ar dating of Campanian Ignimbrite, Campanian G., and Rampolli, F., (1977). Infl ation and Microe- Region, Italy. Int. Geol. Congress, Kyoto, Japan, 24 arthquake activity of Phlegrean Fields, Italy. Bull. Aug.-3 Sept., Abstr., 3: 633. Volcanol., 40:169-188. Delibrias, G., Di Paola, G.M., Rosi, M. e Santacroce, Cundari, A., (1980). Role of subduction in the genesis R., (1979). La storia eruttiva del complesso vulcanico of leucite-bearing rocks: facts on fashion. Contrib Somma-Vesuvio ricostruita dalle successioni pirocla- Mineral Petrol 73: 432-434 stiche del M. Somma. Rend. Soc. It. Mineral. Petrol., D’Antonio M, Tilton GR, Civetta L (1996). Petroge- 35: 411-438 nesis of Italian alkaline lavas deduced from Pb-Sr-Nd Delli Falconi, M., 1538. Dell’Incendio di Pozzuolo isotope relationships. Earth processes: reading the Marco Antonio delli Falconi: English translation in isotopic code. Basu A, Hart S (eds): AGU Monograph Hamilton, W., 1776-9, and in Lobley, J., 1989. Series 95: 253-267 Di Girolamo, P., Ghiara, M.R., Lirer, L., Munno, R., da Toledo, P. G., (1539). Ragionamento del terremoto Rolandi, G. & Stanzione, D. (1984). Vulcanologia e del Nuovo Monte dell’aprimento di Terra in Pozzuolo petrologia dei Campi Flegrei. Bollettino della Società nell’anno 1538. English translation in Hamilton, W., Geologica Italiana 103, 349-413 1776-9, and in Lobley, J., 1989. Di Vito, M. Lirer, L. Mastrolorenzo, G. and Rolandi, De Astis, G., Pappalardo, L., Piochi, M., (2002). Pro- G. (1985). Volcanological map of Campi Flegrei: cida Volcanic History: new insights in the evolution Min. Prot. Civ. Univ. degli Studi di Napoli. of the Phlegraean Volcanic District (Campania region, Di Vito, M. Lirer, L. Mastrolorenzo, G. and Rolandi, Italy). Bull Volcanol: accepted G. (1987). The 1538 Monte Nuovo eruption (Campi De Jorio, A., (1820). Ricerche sul Tempio de Sear- Flegrei, Italy). Bull. Volcanol., 49:608-615. pide: Naples, monumenti inediti di Antichità e belle Dvorak, J.J. and Gasparini P., (1991). History of arti. earthquakes and vertical movement in Campi Flegrei P55 to PW06 n° 6 - from Volume De Natale G., Petrazzuoli, Pingue F., ( 1997). The ef- caldera, Southern Italy: Comparison of precursory fect of collapse structures of ground deformations in events to the A.D. 1538 eruption of Mante Nuovo caldera. Geophy Res Lett (24) 13, 1555-1558. and activity since 1968. Jour. Volcanol. Geoth. Res. De Natale G., Pingue F., Allard P., Zollo A., ( 1991). 48:77-92. Gephysical and geochemical model of the Campi Fle- Dvorak, J.J. and Mastrolorenzo, G. (1991). The grei Caldera. J. Volc Geoth Res, 48:199-222. mechanisms of recent vertical crustal movements in

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo sismica arifl Finetti, I.,andMorelli.,C.,(1974).Esplorazione Spec. Pap..263, 47p. Campi Flegrei caldera,southernItaly. Geol.Soc. Am. (1996). EruzioniplinianedelSomma-Vesuvio esiti Livadie, C. Albore, Mastrolorenzo, G., Vecchio, G. Volcanol. Geotherm.Res.,48(1/2):223-227. levance fortheoriginofCampanianIgnimbrite.J. of the“MuseumBreccia”(CampiFlegrei) anditsre- Lirer, L.,Rolandi,G.andRubin,M.,1991.14Cage Campi Flegrei. Boll. Soc.Geol.It.,106:447-460. G. (1987b).L’eruzione delMonteNuovo (1538) nei Lirer, L.Rolandi,G.Di Vito, M.andMastrolorenzo, tano (CampiFlegrei). PerMineral44:103:118. Lirer L.andMunnoR,(1975).Il Tufo GialloNapole- 226-324. volcanological evolution ofCampiFlegrei. EOS68, Lirer L.,LuongoG.,ScandoneR,(1987a).Onthe ca eorientale.Rome,istitutoEnc.Ital. Treccani. Levi, D.,(1969).Enciclopediadell’arte Antica classi- na of Vesuvius anditsneighbourhood(London). pointed fortheinvestigation ofthevolcanic phenome- Johnston Lavis, H.F., 1889.ReportofCommitteeap- cheometria, Napoli,95-98. Albore Livadie (eds.)Lescienzedella Terra el’ar- piroclastiti del79 A.D. adErcolanoIn:D’Amicoand deposizione, medianteprocedurepaleomagnetichedi na, G.,(1998).Determinazionedelletemperaturedi Incoronato, A., Mastrolorenzo,G.,Pagano, M.,Spi- trib MineralPetrol69:151-165 87Sr/86Sr evidence fromtheItalianvolcanics. Con- mination versus enrichedmantle:143Nd/144Ndand Hawkesworth CJ, Vollmer R(1979).Crustalconta- man foreshorenearNaples. Archeologia, 58:62. Gunther, A. E.,(1903). The submerged GreekandRo- Geophys. Res.103,B9:20921-20933. dynamical processesinthegeothermalsystem.J. at CampiFlegrei caldera: The roleofthermalfl no, (1998).Genesisandevolution ofunrestepisodes G., Castagnolo,D., Troise, C.,Mita,D.G.,andRossa- Gaeta, F.S., DeNatale,G.,Peluso,F., Mastrolorenzo, Journal ofScience,new series,1:260-286. Pozzuoli andphenomenawhichitexhibits. Edinburg Naples; Number5,onthetempleofJupiterSerapisat Forbes, J.D.,(1829).PhysicalnoticesintheBayof nol. Geotherm.Res.,56:205-220. cement oftheCampanianIgnimbrite,Italy. J. Volca- Mobility ofalarge-volume pyroclastic fl Fisher, R.V., Orsi,G.,Ort,M.andHeiken, G.1993. 222. Bollettino diGeofi essione deiGolfi sica teoricaedapplicata,16:175- diNapoliePozzuoli. ow -empla- uid-

Naples, StamperiaReale. puteolana volgarmente detta Tempio diSearpide. Niccolini, A., (1845).Descrizionedellagrandeterma di diciannove secoli.Naples,Flauntina,p.11-52. la costadimalfi le varie altezzetracciatedellasuperfi Niccolini, A., (1839). Tavola cronologico-metricadel- Institute. 36:99-134. surface aroundthem.BulletinoftheEarthResearch various volcanoes andthedeformationofround Mogi, K.,.(1958).Relationsbetwenntheeruptionsof Geotherm. Res.,68:325-339. implication fortheeruptive dynamics.J. Volcanol. processes inashallow, zonedmagmachamberand seo (CampiFlegrei, Italy):Fractionalcristallizzation Adabbo, M.,1995. The eruptionoftheBrecciaMu- Melluso, L.,Morra, V., Perrotta, A., Scarpati,C.and Nature 419:769-770 (2001). Herculaneumvictimsof Vesuvius in AD 79. ronato, A., Baxter, P.J., Canzanella, A., Fattori, L. Mastrolorenzo,G., Petrone,P.P., Pagano, M.,Inco- re. J. Volcanol. Geotherm.Res.113:19-36 environmental impactattheendofRomanEmpi- Pollena eruptionofSomma-Vesuvius (Italy)andits deucci., J., Albore Livadie, C.(2002) The 472 AD Mastrolorenzo, G.,Palladino, D., Vecchio, G., Tad- nol. Geotherm.Res.109:41-53 in magmariseandvesiculation mechanisms.J. Volca- Campi Flegrei volcanic fi Vesicularity ofvarious typesofpyroclastic depositsof Mastrolorenzo, G.,Brachi,L.,Canzanella, A., (2001). Flegrei (southItaly).Bull. Volcanol, 54:561-572. Mastrolorenzo, G.(1994). Averno tuff ringinCampi Geotherm. Res.58:217-237. tion anditsrelationtoeruptioncycles. J. Volcanol. Vesuvius 1906:acasestudyofparoxysmalerup- Mastrolorenzo G.,MunnoR.andRolandi(1993) 61, 48-63. ply ofthe1944eruption Vesuvius. Bull Volcanol., Shallow anddeepreservoirs involved inmagmasup- Marianelli, P., Métrich,N.andSbrana, A. (1999): pra Pozzuolo.FromParancandola 1946. che contienelistupendietgrandiprodigiapparsiso- Marchesino F., 1538.CopiadeunaletteradiNapoli don ,JohnMurray. 64-179. Lyell, C.,(1872).Principlesofgeology. 11ed:Lon- 1-2 48, Res., Volcanol.J. Geoth. Issue, cial Luongo G.,ScandoneR.,(1991).CampiFlegrei, Spe- 21 dicembre1996.Napoli1998. zionale Amici diPompei. Atti dlConvegno. Pompei archeologici dell’areanolana. Associazione interna- edilpromontoriodiGaetanelcorso eld: evidencesof analogies cie delmarefra 27-05-2004, 15:13:15 ACTIVE VOLCANISM AND RELATED EVENTS IN CAMPANIA: PRIMARY AND SECONDARY EFFECTS OF EXPLOSIVE VOLCANIC ERUPTIONS

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Oliveri del Castello, A., and Quagliariello, MT, strutturali. Geological Society of Italy Memoir. 27: 1969. Sulla genesi del bradisismo fl egreo. Atti 133-149. Assoc.Geofi sica Italiana. 18th Congresso Napoli p. Piochi M, Civetta L, Orsi G (1999) Mingling in the 557-594. magmatic system of Ischia (Italy) in the past 5 Ka. Orsi G., de Vita S.and Di Vito M.A., (1996). The re- Mineral Petrol 66 (4): 227 – 258 stless, resurgent Campi Flegrei nested caldera (Italy): Piochi, M., Pappalardo, L. and De Astis, G. (2003): constraints on its evolution and confi guration. J. Vol- Geochemical and isotopical variation within the Cam- canol. Geotherm. Res., 74: 179-214.; panian Comagmatic Province: implications on mag- Orsi, G., D’Antonio, M., de Vita, S. and Gallo, G., ma source composition. Ann. Geophys., accepted (1992). The Neapolitan Yellow Tuff, a large-ma- Polacci M., Poli L., Rosi M., (2003). The Plinian pha- gnitude trachytic phreatoplinian eruption: eruptive se of The Campanian ignimbrite eruption (Phlegraean dynamics, magma withdrawal and caldera collapse. J. Field, italy): evidence from density measurements Volcanol. Geotherm. Res., 53: 275-287. and textural characterization of pomice. Bull Volc65: Ort M., Orsi G., Pappalardo L. and Fisher R.V., 418- 432. (2003). Emplacement processes in a far-traveled Rittman, A., Vighi, L., Ventriglia, V., and Nicotera, P., dilute pyroclastic current: anisotropy of magnetic su- (1950). Rilievo geologico dei Campi Flegrei. Bolletti- sceptibility studies of the Campanian Ignimbrite. Bul. no della Società Geologica Italiana. 69: 117-362. Volcanol., 65:55-72. Rolandi G., F. Bellucci, M. T. Heizler, H. E. Belkin3 Pappalardo L, Civetta L, D’Antonio M, Dein AL, Di and B. De Vivo (2003). Tectonic controls on the ge- Vito MA, Orsi G, Carandente A, de Vita S, Isaia R, nesis of ignimbrites from the Campanian Volcanic Piochi M (1999). Chemical and isotopical evolution Zone, southern Italy Mineralogy and Petrology : Vol of the Phlegraean magmatic system before the Cam- 79,3 – 31 panian Ignimbrite (37 ka) and the Neapolitan Yellow Rolandi G., Mastrolorenzo G., Barrella A.N. and Bor- Tuff (12 ka) eruptions. J Volcanol Geotherm Res 91: relli A. (1993). The Avellino plinian eruption of Som- 141-166 ma-Vesuvius (3760 y. B.P.: The progressive evolution Pappalardo L, Piochi M, D’Antonio M, Civetta L, from magmatic to hydromagmatic style.J. Volcanol Petrini R (2002). Evidence for multi-stage magma- Geotherm. Res. 58, 67-88. tic evolution during the past 60 ka at Campi Flegrei Rosi, M. and Santacroce, R. (1983): The AD 472 (Italy) deduced from Sr, Nd and Pb isotope data. J “Pollena” eruption: volcanological and petrological Petrol 43 (7): 1415-1434 data for this poorly-known, plinian-type event at Ve- Pappalardo L., Piochi M., Mastrolorenzo G. (2003). suvius. J. Volcanol. Geotherm. Res., 17, 249-271. The 3800 yr BP – 1944 AD magma plumbing system Rosi, M. and Sbrana, A., 1987. Phlegrean Fields. of Somma-Vesuvius: constraints on its behaviour and CNR, Quaderni de “La Ricerca Scientifi ca”, 114: present satte through a review of isotope data. Ann. 1-175. Geophys., in press. Rosi, M., Vezzoli, L., Aleotti, P., De Censi, M., Parascandola, A.,(1946). Il Monte nuovo ed il Lago (1996). Interaction between caldera collapse and Lucrino, Napoli. Natural Society Bulletin. 60: 314p. eruptive dynamics durino the Campanian ignimbrite Parascandola, A.,(1947). I fenomeni bradisismici eruption, , Italy. Bull. Volcanol. 57: del Serapeo di Pozzuoli. Naples,privately publised, 541-554. 156p. Rossano, S., Mastrolorenzo, G., De Natale, G., and Peccerillo A., 2001. Geochemical similarities between Pingue, F. 1996. Simulation of pyroclastic fl ow mo- the vesuvius, Phlegraean Fields and stromboli Volca- vement: an inverse approach. Geoph. Res. Letters. 23, noes: petrogenetic, geodynamic and volcanological 3779-3782. implications. Mineral. Petrol, 73: 93-105. Rossano S., Mastrolorenzo G., De Natale G., (1998). Perrotta, A. and Scarpati, C., 1994. The dynamics of Computer simulations of pyroclastic fl ows of Som- P55 to PW06 n° 6 - from Volume the Breccia Museo eruption (Campi Flegrei, Italy) and ma-Vesuvius volcano. Journ. Volcan. Geotherm Res, the signifi cance of spatter clasts associated with lithic 82:113-134. breccias. J. Volcanol. Geotherm. Res., 59: 335-355. Rossano S., Mastrolorenzo G., De Natale G., (2003). Pescatore, T., Diplomatico, G., Senatore, M.R., Tra- Numerical simulation of Pyroclastic Density Currents mutoli, M., and Mirabile, L., (1984). Contributiallo on Campi Flegrei topography: a tool for statistical studio del golfo di Pozzuoli; aspetti stratigrafi ci e hazard estimation. Journ. Volcan. Geotherm Res, in

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Volume n° 6 - from P55 to PW06 P67 - P67 Leader: G.Mastrolorenzo Scherillo, A., (1955).Petrografi nol. Geotherm.Res.pp.1-31. activity oftheNeapolitanvolcanoes (Italy)J. Volca- (1991). The structureoftheCampanianPlainand Scandone, R.;Bellucci,F.; Lirer, L.;Rolandi,G., press. (1985) The eruption of Vesuvius in A.D. 79.National Sigurdsson, H.,S.Carey, W. Cornell& T. Pescatore Opera, Florence.In:Lobley, 1889. lani SimoniPortiiNeapolitaniEpistola. Simone Porzio,(1551).Deconfl dei NaturaleinNapoli.88:27-47. di Pozzuoli(Napoli).Napoli,BollettinodellaSocietà storiche delbradisismoputeolanorivelate dalSerapeo Sicari, L.,(1979). Alcune osservazioni sulletrefasi Pontamiana, Napoli.6:27-37. carta stratigrafi Scherillo, A., andFranco,E.,(1967)Introduzionealla tiche. Napoli.22,317-330. conti dell’Accademiadellescienzefi fl egrei. Tufo Giallo,Mappamonte,Pozzolana.Rendi- ca delsuolodiNapoli. Atti Accademia agratione Agri Puteo- a chimicadeitufi siche ematema-

data. J. Volcanol. Geotherm.Res.,67:263-290. ted fromstratigraphic,chemical,andgranulometric mechanisms oftheNeapolitan Yellow Tuff interpre- Wohletz, K.,Orsi,G.andde Vita, S.,1995.Eruptive 74: 229-239. magmas, 1. A discussioncontribution. ChemGeol Vollmer, R.,(1989).Ontheoriginof potassic period. J. Volcanol. Geotherm.Res.,58,291-313. chemistry of Vesuvius volcanics during1631-1944 Villemant, B., Trigila R.andDe Vivo B.(1993).Geo- Lett.(24)13, 1575-1578. at campiFlegrei andRabaulcalderas.Geophys Res model forearthquake generationduringunrestcrises Troise C.,DeNataleG.,PingueF., Zollo A., (1997). A Volcanology andGeotherm.Res109:1-12. at calderas:anapplicationtoCampiFlegrei (Italy).J. thermal fl lorenzo G.,DeNatale(2001). A 2Dmechanical Troise C.,CastagnoloD.,PelusoF, GaetaFS,Mastro- Geographic Research,1,332-387. uid dynamicalmodelforgeothermalsystem 27-05-2004, 15:13:17 Back Cover: fi eld trip itinerary

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