Age and whole rock–glass compositions of proximal pyroclastics from the major explosive eruptions...

Journal of Volcanology and Geothermal Research 177 (2008) 1–18

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Age and whole rock–glass compositions of proximal pyroclastics from the majorexplosive eruptions of Somma-Vesuvius: A review as a tool fordistal tephrostratigraphy

Roberto Santacroce a,⁎, Raffaello Cioni b, Paola Marianelli a, Alessandro Sbrana a, Roberto Sulpizio c,Giovanni Zanchetta a, Douglas J. Donahue d, Jean Louis Joron e,f

a Dipartimento di Scienze della Terra,Università di Pisa, via Santa Maria 53, 56126 Pisa, Italyb Dipartimento di Scienze della Terra, Università di Cagliari, Via Trentino 51, 09127 Cagliari, Italyc Dipartimento Geomineralogico,Università di Bari, via Orabona 4, 70125 Bari, Italyd National Science Foundation Accelerator Facility for Radioisotope Analysis, University of Arizona, Tucson, AZ 85721, United Statese Groupe des Sciences de la Terre, Laboratoire Pierre Sue, Saclay, Gif-sur-Yvette, Francef Institute de Physique du Globe de Paris 4, Place Jussieu, 75005, Paris, France

⁎ Corresponding author.E-mail address: [email protected] (R. Santacroce).

0377-0273/$ – see front matter © 2008 Elsevier B.V. Aldoi:10.1016/j.jvolgeores.2008.06.009

A B S T R A C T
A R T I C L E I N F O
Available online 22 June 2008

Keywords:

A review of compositionalcompositions (major elemefor long-distance correlatio

Vesuviustephrostratigraphytephrochronologyvolcanic glasspyroclastics

n. A critical review of published and new geochronological data is also provided.All available 14C ages are calibrated to give calendar ages useful for the reconstruction of the volcanologicalevolution of the volcanic complex. The pyroclastic deposits of the four major Plinian eruptions (22,000 yr calBP “Pomici di Base”, 8900 yr cal BP “Mercato Pumice”, 4300 yr cal BP “Avellino Pumice”, and A.D. 79 “PompeiiPumice”) are widely dispersed and allow a four-folded, Plinian to Plinian, stratigraphic division: 1. B–M

data of the major explosive eruptions of Vesuvius is presented, comparingnts) of whole rock with glass shards from the proximal deposits, hopefully useful

(between Pomici di Base and Mercato); 2. M–A (between Mercato and Avellino); 3. A–P (between Avellinoand Pompeii); 4. P–XX (from the Pompeii Pumice to the last erupted products of the XXth century). Withineach interval, the age, lithologic and compositional features of pyroclastic deposits of major eruptions,potentially useful for tephrostratigraphic purposes on distal areas, are briefly discussed. The Vesuvius rocksare mostly high Potassic products, widely variable in terms of their silica saturation. They form three groups,different for both composition and age: 1. slightly undersaturated, older than Mercato eruption; 2. mildlyundersaturated, from Mercato to Pompeii eruptions; 3. highly undersaturated, younger than Pompeiieruption. For whole rock analyses, the peculiar variations in contents of some major and trace elements aswell as different trends in element/element ratios, allow a clear, unequivocal, easy diagnosis of the groupthey belong. Glass analyses show large compositional overlap between different groups, but selected elementvs. element plots are distinctive for the three groups. The comparative analysis of glass and whole rock majorelement compositions provides reliable geochemical criteria helping in the recognition, frequently notobvious, of distal products from the different single eruptions.

© 2008 Elsevier B.V. All rights reserved.

1. Introduction

Past explosive activity of Somma-Vesuvius has been characterizedby many eruptions largely variable in magnitude, intensity andcomposition of the involved products (Cioni et al., in press). Thelarge magnitude and intensity of some eruptions led to dispersal ofpyroclastic deposits over wide areas, so giving them a strong potentialfor tephrostratigraphic studies. In addition, many of these eruptionsare characterized by a marked compositional zoning, which gives

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them a unique signature. The geochemical and chronological frame-work presently available for Somma-Vesuvius activity requires higherresolution and reliability. This deficiency is particularly evident whencomparing and correlating, on a compositional basis, well-describedpumice- or scoria-rich proximal tephra with their less well-studiedash distal counterparts. This partially relates to the fact that thepublished major element chemistry of proximal products is basedprincipally on whole rock XRF analyses, whereas the major elementcomposition of distal tephra comes from glass shards ormicro-pumicemicroanalyses (e.g. Paterne et al., 1986,1988; Siani et al., 2004;Wulf etal., 2004). This discordance reduces the reliability of these tephra asstratigraphic and chronological markers in the sedimentary succes-sions of the Mediterranean Basin.

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Table 1Summary of existing ages of the Somma-Vesuvius eruption discussed in the text along with alternative nomenclature reported in literature

Eruption 14C yr BP 14C cal yr BP Other datingmethods

Preferred age(this paper)

Alternative eruption nomenclature References

AD 1631 470±55a 520±40 AD 1631 90 BPb AD 1631 aSantacroce (1987)330±55a 410±70 bWulf et al. (2004)

AS 5a 545±50a 580±50 540±30 cal BP aCioni et al. (in press).475±50a 520±40

AS 4 a–ba 1181±46 1100±70 1100±70 cal BP This paperaCioni et al. (in press)

AS 4a 1165±55 1100±80 1160±80 cal BP PM6 in Santacroce and Sbrana (2003) This paper1230±55 1160±80 Fourth Medieval in Rolandi et al. (1998) aCioni et al. (in press)

AS 3a 1265±55 1200±70 1270±35 cal BP PM3-4-5 in Santacroce and Sbrana (2003) This paper1355±55 1280±50 1290±30 cal BP Third Medieval in Rolandi et al. (1998)

(several fallout scoria beds separated by reworked ash)

aCioni et al. (in press)1335±46 1260±50 1310±30 cal BP1370±50 1290±501372±46 1290±401340±50 1270±501380±60 1310±501425±55 1350±50

AS 2a 1570±50 1470±60 PM2 in Santacroce and Sbrana (2003) This paperSecond Medieval in Rolandi et al. (1998) aCioni et al. (in press)

AS 1c – – AD 512a AD 512 PM1 in Santacroce and Sbrana (2003) a Andronico et al. (1995)1420 BPb First Medieval in Rolandi et al. (1998) b Wulf et al. (2004)

cCioni et al. (in press)Pollena 1630±50a§§ 1530±70 AD 472 AD 472 a Delibrias et al. (1979)

1650±30b 1570±40 1440 BPc bThis work1630±50b 1530±70 c Wulf et al.(2004)

Pompei 2085±80a 2080±110 AD 79 AD 79 a Vogel et al. (1990)2120±60b 2140±110 b Rolandi et al. (1998)1805±40c§ 1750±60 cDelibrias et al. (1979)

AP6 – – 217–216 BC ? Stothers and Rampino (1983)AP4 – – 3990 – Third Protohistoric in Rolandi et al. (1998) Wulf et al. (2004)AP3 2710±60a 2830±50 4020b 2830±50 Third Protohistoric in Rolandi et al. (1998) a Rolandi et al. (1998)

b Wulf et al. (2004)AP2 3000±200a 3170±240 4150e 3500±40 cal BP Second Protohistoric in Rolandi et al. (1998) a Santacroce (1987)

3240±45b⁎⁎ 3480±50 b Rolandi et al. (1998)3400±160c 3680±190 cTerrasi et al. (1994)3300±80d 3540±90 d Vogel et al. (1990)

e Wulf et al. (2004)AP1 3220±65a 3460±70 – 3500±60 cal BP Firts Protohistoric in Rolandi et al. (1998) a Andronico et al. (1995)

3420±300b⁎ 3671±370 b Rolandi et al. (1998)3270±50e 3500±60 eThis paper

Pomici diAvellino

3360±40a 3600±60 4310d 4365±40 cal BP a Vogel et al. (1990)3460±65b 3740±90 bTerrasi et al. (1994)3590±25c 3900±40 c Andronico et al. (1995)3675±57d 4010±80 d Wulf et al. (2004)3920±50e 4350±70 e Watts et al. (1996)3960±60f 4410±60 fThis paper3850±55g 4280±100 g Pantosti et al. (1993)

Pomici diMercato

7910±100a 8780±150 9680e 8890±90 cal BP Pomici Gemelle and Pomici e proietti in Delibrias et al. (1979) aDelibrias et al. (1979)7870±50b 8710±90 Ottaviano Formation in Rolandi et al. (1993a,b,c) bAlessio et al. (1974)8098±71c° 9010±130 c Wulf et al. (2004)8010±35d 8890±90 d Andronico et al. (1995)

e Wulf et al. (2004)PomiciVerdoline

14,420±160a 17730±200 17,560d 19265±105 cal BP Novelle-Seggiari Formation in Ayuso et al. (1998) a Delibrias et al. (1979)15,500±170a 18790±140 b Andronico et al. (1995)16,780±170b 20010±260 c Siani et al. (2001)16,130±110b 19300±150 d Wulf et al. (2004)16,020±130c 19230±150

Pomici di Base 17,050±140a 20220±200 22520±1000e 22,030±175 yr cal BP Sarno Formation in Ayuso et al. (1998) a Delibrias et al. (1979)19,170±420b 23000±460 19280f b Bertagnini et al. (1998)18,750±420b 22520±570 c Andronico et al. (1995)18,300±180c 22030±250 d Siani et al. (2004)18,300±150d 22030±240 e Capaldi et al. (1985)

f Wulf et al. (2004)

Table 1 (from Santacroce R, Cioni R, Marianelli P, Sbrana A, Sulpizio R, Zanchetta G, Donahue D J, Joron JL (2007) Age and whole rock–glass compositions of proximal pyroclastics fromthe major explosive eruptions of Somma-Vesuvius: a review as a tool for distal tephrostratigraphy. JVGR, in press).Italic: 14C age obtained on soil organic matter; Plain: 14C age obtained on charcoals; Bold: average from soil and charcoal as reported by some authors. °Average of old determinationprobably including a too old age of 8470±100 of Delibrias et al. (1979). ⁎Average of three 14C age determination on charcoals reported by Rolandi et al. (1998). ⁎⁎Average of three 14Cage determination on charcoals reported by Rolandi et al. (1998). §Average of two 14C age determination on charcoal reported by Delibrias et al. (1979). §§ Average of two 14C agedetermination on charcoal reported by Delibrias et al. (1979).

2 R. Santacroce et al. / Journal of Volcanology and Geothermal Research 177 (2008) 1–18

A second problem is the lack of well-established geochemicalparameters for distinguishing Vesuvian trachytic to latitic pyroclastics,which were both erupted during the oldest phases of activity (e.g.Santacroce, 1987), from the analogous products originated from the

nearby Campi Flegrei caldera (e.g. Rosi and Sbrana, 1987; Civetta et al.,1997; Pappalardo et al., 1999). Although the eruptive history ofSomma-Vesuvius is reasonably well constrained for the last ca 22 ka(e.g. Cioni et al., 1999), its older activity remains a matter of debate

3R. Santacroce et al. / Journal of Volcanology and Geothermal Research 177 (2008) 1–18

(Santacroce, 1987; Bocchini et al., 2001; Sulpizio et al., 2003; Di Vitoet al., 2008; Di Renzo et al., 2007), and the chronology of someimportant explosive eruptions is not well constrained.

This paper provides a review of compositional data for all majorexplosive eruptions of Somma-Vesuvius, including whole rockcompositions and data from glass shards of the proximal deposits.Turney et al. (2008) report major element analyses from wavelengthdispersive spectrometry (WDS) on glass in proximal pyroclasts from14 eruptions of Campi Flegrei and Procida, and three eruptions ofVesuvius (Mercato, Avellino, Pompeii). These results are comparedwith our data. A review of the chronology and nomenclature of theseeruptions, in the light of existing and new data, is also provided, inorder to give a reliable and robust chronological framework for theexisting data. Analytical methods and sources of data are given inAppendix A and, for age determinations, in Table 1.

2. Stratigraphy and chronology

The Somma-Vesuvius volcanic complex (Fig. 1) consists of an oldervolcano dissected by a summit caldera, Monte Somma, and of a recentcone, Vesuvius, which grew within the caldera after the A.D. 79“Pompeii” eruption (Santacroce, 1987; Cioni et al., 1999). Actually theRoman name Vesuvius (or Vesbius) was referring to the old volcano,and only starting from the Vth century, chroniclers make mention ofMt Somma, as the highest (“summa”) peak of the mountain which, atthat moment, referred to the older one. Borehole data show that thebase of the Somma-Vesuvius lies on the Campanian Ignimbritedeposits (Bocchini et al., 2001; Santacroce and Sbrana, 2003; DiRenzo et al., 2007), being therefore younger than ca. 39 ka (De Vivoet al., 2001). The paper focuses on ages obtained from proximal tomedial–proximal terrestrial deposits (Table 1) with the exception ofages of tephra layers from Lago Grande di Monticchio (Southern Italy),as this record is becoming a standard reference for the central

Fig. 1. Quickbird satellite image on July 12, 2002 showing the Mt. Somma caldera, the VesuviuCampana-Ottaviano discussed in the text. Town names in black; mentioned localities ininterpretation of the references to colour in this figure legend, the reader is referred to the

Mediterranean area (Wulf et al., 2004, 2008). The ages of tephra layersat Monticchio (Wulf et al., 2004, and references therein) have beenobtained using a “varve supported sedimentation rate chronology”with a roughly estimated dating error of 5–10% and reported as varve-ages BP in Table 1.

14C ages from bulk soil samples obtained before 1980 (e.g. Alessioet al., 1974; Delibrias et al., 1979, Table 1) are frequently younger thanages obtained later for the same deposit, confirming that these dataare not particularly useful for refining the chronology of someeruptions. They will not be considered further.

2.1. Explosive activity older than ca 22 ka (of uncertain source)

The products of the activity which formed the Somma stratovol-cano are exposed in the inner wall of the caldera (Santacroce andSbrana, 2003). They consist of a pile of lava flows spatter and scoriadeposits reflecting dominantly effusive activity (Johnston Lavis, 1884;Rittmann and Ippolito, 1962; Santacroce, 1987). No large scalepyroclastic deposits older than 22 ka that clearly sourced fromSomma-Vesuvius have been recognized in proximal sectors. In medialand distal areas, several pyroclastic deposits occur between theCampanian Ignimbrite (Campi Flegrei) and Pomici di Base (Somma-Vesuvius) deposits. Some of these have been correlated to the activityof Campi Flegrei, whereas the provenance of three deposits, whoseavailable data will be discussed, is still a matter of debate.

Analyses of samples from pyroclastic deposits penetrated by aborehole located near Camaldoli della Torre eccentric apparatussuggest the occurrence of important explosive activity in the Vesuviusarea just after the deposition of the Campanian Ignimbrite (CdTl layerin Di Renzo et al., 2007). The thickness of these deposits (ca. 60m)maysuggest a local source (Di Renzo et al., 2007). Di Vito et al. (2008)tentatively correlated these deposits to medial–distal pyroclasticfallout deposits of similar composition recognized on the mountains

s cone and surroundings. Dashed lines suggest the location of tectonic alignment Palmayellow. Image NASA of public domain from: http://visibleearth.nasa.gov/view. (For

web version of this article.)

http://visibleearth.nasa.gov/view


bordering the Campanian plain (“Schiava Pumice” of Sulpizio et al.,2003; Zanchetta et al., 2004) and previously considered as originatedby Ischia volcanoes (Sulpizio et al., 2003).

Widely dispersed pyroclastic deposits correlated with the so-called “Codola eruption” (Alessio et al., 1974; Arnò et al., 1987) occurin many medial to distal marine and terrestrial successions(Bocchini et al., 2001; Sulpizio et al., 2003; Wulf et al., 2004;Munno and Petrosino, 2007; Di Vito et al., 2008; Giaccio et al.,2008). The Codola deposits have a calibrated age of ca 33 ka(Giaccio et al., 2008). Bocchini et al. (2001) reported the presenceof the Codola tephra in a succession drilled by a geothermal bore-hole located near Trecase, on the southern slopes of Vesuvius(Fig. 1). Sulpizio et al. (2003) proposed an origin from Campi Flegreifor Codola pyroclastics, whereas Giaccio et al. (2008) and Di Vitoet al. (2008) did not rule out the possibility of a Somma-Vesuviusorigin.

Very recently, Di Vito et al. (in press) suggested the occurrence ofmoderate to strong explosive activity north-east of Somma-Vesuvius,possibly along the tectonic alignment of Palma Campania-Ottaviano(Fig. 1) in the period between 39 and 22 ky BP. Deposits that mayrepresent this activity occur at the base of the Appennine Mountains,within a clear phase of aggradation of volcaniclastic alluvial fansrelated to reworking of pyroclastic fall deposits of the so-called“Taurano eruption” (Zanchetta et al., 2004).

2.2. Explosive activity from 22 ka to 1631

The stratigraphy of Somma-Vesuvius volcanic products postdatingMt. Somma was studied and reconstructed starting from the end ofthe XIXth century (Delibrias et al., 1979; Johnston Lavis, 1884;Santacroce, 1987; Cioni et al., 1999; Santacroce and Sbrana, 2003).The deposits of some 40 explosive eruptions are recognized, includingsome products related to Campi Flegrei activity. The highly variableeruptive styles of Somma-Vesuvius eruptions are reviewed anddiscussed in Cioni et al. (in press).

Fourmajor Vesuvius Plinian eruptions are recorded by their depositsin the volcanic succession of the circumvesuvian area: the “Pomici diBase”, the “Mercato Pumice”, the “Avellino Pumice”, and the “PompeiiPumice” (A.D. 79). The pyroclastic deposits of these four eruptionsrepresent clearly distinctive stratigraphic markers which allowed us todefine four distinct stratigraphic intervals (Fig. 2). These intervals are

Fig. 2. Synthetic eruptive history of the last 22,000 years of Somma-Vesuvius (calibrated aquestionmark indicates uncertainty in age. VEI is the Volcanic Explosivity Index of Newhall andeposits of the four Plinian (VEI=5) eruptions define four stratigraphic intervals (B–M,M–A,one). Coupling age and silica undersaturation degree three groups were distinguishedundersaturated, from Mercato to Pompeii eruptions; highly undersaturated, younger than P

here indicated as: 1. B–M(between Pomici di Base andMercato); 2.M–A(between Mercato and Avellino); 3. A–P (between Avellino andPompeii); 4. P–XX (from the Pompeii Pumice to the last eruptedproducts of the XXth century). Each interval includes the deposits of theoldest Plinian eruption and closes at the base of the following Pliniandeposit. This subdivision is justified in the field by the presence of well-developed paleosols covered by the products of the Plinian eruptions(Santacroce and Sbrana, 2003). Table 2 summarizes themain features ofdeposits and the fallout dispersal of the explosive eruptions potentiallyuseful for tephrostratigraphic studies in distal areas.

2.2.1. The Pomici di Base Plinian eruption and the B–M intervalThe Pomici di Base eruption (Delibrias et al., 1979, but other names

can be found in the literature: “Basal”, “Pomici Basali”, “Sarno”—Capaldi et al., 1985; Arnò et al., 1987; Andronico et al., 1995) is theoldest and largest, caldera forming, explosive event which can beunequivocally assigned to the eruptive history of Vesuvius. Bertagniniet al. (1998) and Cioni et al. (1999), argued that this eruption wassourced from a vent located 1–2 km west of the summit of theancestral Somma cone. The eruption progressed through three mainphases: (1) opening, marked by the deposition of thin ash and pumicefall deposits; (2) Plinian, dominated by pumice and scoria falloutforming thick deposits dispersed in an E–NE direction; (3) phreato-magmatic, during which the emplacement of lithic-rich pyroclasticfall, surge and flow deposits accompanied the caldera collapse. ThePlinian fall, with an estimated volume of 4.4 km3, is by far the mostsignificant deposit. It consists of compositionally zoned products froma basal white, K-trachytic pumice bed to an upper black, K-latiticscoria. Two recent 14C ages on charcoal (Andronico et al., 1995; Sianiet al., 2004) yield an averagemaximum age of 22,030±175 yr cal BP, inagreement with a K/Ar determination on sanidine (22,520±1000 yrBP) by Capaldi et al. (1985).

After the Pomici di Base eruption, the activity resumed with theemission of K-latitic products through eccentric vents in both thenorthern (lava flows and scoriae from Vallone San Severino andVallone di Pollena) and southern (Camaldoli della Torre cinder cone;Joron et al., 1987) sectors of the volcano.

The second largest event of this interval was the subplinian“Greenish Pumice” eruption, also called “Pomici Verdoline” (Delibriaset al., 1979; Santacroce and Sbrana, 2003) and “Seggiari-Novelle”(Ayuso et al., 1998). This large eruption was characterized by a

ges) as recorded by the stratigraphic successions and selected historical sources. Thed Self (1982). Black dotted arrows refer to probably Phlaegrean deposits. The pyroclasticA–P, P–XX, each starting with the oldest Plinian eruption and closing before the younger(see also Fig. 3): 1. slightly undersaturated, older than Mercato eruption; 2. mildlyompeii eruption.


complex alternation of pyroclastic fall and flow deposits recording thetransition from an initial phase of quasi-steady discharge (resulting ina convective column) to phases of more discontinuous, pulsatingactivity, with the formation of Vulcanian to Subplinian plumes (Cioniet al., 2003). A well-developed paleosol is locally present underneath

Table 2Main features and dispersal areas of pyroclastic deposits from the eruptions discussed in th

the Greenish Pumice deposits. Two recently determined 14C ages oncharcoal yield an average maximum age of 19,265±105 cal yr BP. Fourother pumice fallout layers occur between Greenish Pumice andMercato deposits on the slopes of Vesuvius. The thickest of theserefers to the Campi Flegrei Plinian eruption of Agnano Pomici

e text

(continued on next page)

Table 2 (continued )


Principali (Agnano P.P.; Di Vito et al., 1999). The other three depositscrop out discontinuously and are less widely dispersed (two older andone younger than Agnano P.P.), and are also probably of Phlaegreanprovenance. The oldest unit, the Lagno Amendolare Pumice, has longbeen considered as a Vesuvius deposit (Delibrias et al., 1979), butAndronico et al. (1995) and Andronico (1997) have attributed it toCampi Flegrei, basing on a reconstruction of the dispersal area. Noproximal counterpart of the Lagno Amendolare Pumice inside theCampi Flegrei caldera has been so far recognized.

2.2.2. The Mercato Plinian eruption and the M–A intervalThe deposits of the Mercato eruption (2–3 km3), recognized by

Johnston Lavis (1884), were first named byWalker (1977) by referenceto a stratigraphic section near Mercato San Severino village. Delibriaset al. (1979) refer to them as “Pomici Gemelle” (twin pumice) and“Pomici e Proietti”, erroneously attributing the upper lithic-richerpumice fall bed to a distinct eruption, while Rolandi et al. (1993b)called these deposits the “Ottaviano pumice”. According to Cioni et al.(1999) the eruption occurred from a vent located close to the presentVesuvius cone, and again was characterized by three main phases(Opening, Plinian, and Phreatomagmatic). The Plinian fall depositsform about 90% of eruptedmaterial and consist of three ENE dispersedunits separated by ash falls and strongly channelled, small-volume,pumice-rich PDC deposits. Two features of the Mercato deposits arepeculiar with respect to the other Vesuvius Plinian eruptions: i) theabsence of compositional zoning (the whole deposit has a nearlyhomogeneous K-phonolitic composition), and ii) the poorly developedphreatomagmatic phase, whose products are restricted to the volcanoslopes. The three available 14C ages on this eruption, obtained fromsoil organic fraction, give an average maximum age of 8890±90 cal yrBP.

After the Mercato eruption, Vesuvius entered a long rest and noevidence has been so far found of significant activity before thefollowing Avellino Plinian eruption. The Agnano Monte Spina pumice

fall deposit from Campi Flegrei is the only widespread layer thatoccurs on the volcano slopes in theMercato–Avellino interval. At somelocalities, it occurs between two other, discontinuous and partlypedogenized, trachytic fall deposits (MA1 and MA2), possibly relatedto Campi Flegrei activity (Andronico et al., 1995; Santacroce andSbrana, 2003).

2.2.3. The Avellino Plinian eruption and the A–P interplinian intervalThe pyroclastic deposits of the Avellino eruption (Lirer et al., 1973;

Arnò et al., 1987; Rolandi et al., 1993a; Cioni et al., 2000) have a volumeclose to that of Mercato (1–2 km3). The eruptive sequence is similar tothat of the other Vesuvius Plinian events, with Opening, Plinian andPhreatomagmatic phases of activity distinguished on the basis ofdeposit characteristics. The areal distribution and the facies variationsof the products indicate that the vent areawas in a position coincidingwith the Piano delle Ginestre, on thewestern slope of the volcano. Thepyroclastic fall deposits show a sharp change in colour from white inthe lower half to grey at top, reflecting a change in the eruptedmagmafrom phonolitic to tephriphonolitic. The fall deposit is dispersed to thenorth-east, even if the grey pumice deposit exhibits a counter-clockwise rotation of 15–20° with respect to the underlying whitepumice (Cioni et al., 2000). A caldera collapse, enlarging the Pomici diBase caldera (Cioni et al., 1999), marked the transition from Plinian toPhreatomagmatic phase. During the latter, a pulsating column formeda giant tuff conemantling thewestern rimof the caldera and generatedmostly pyroclastic flows and surges, whose deposits, peculiar for theirabundance (1.0 km3 according to Rolandi et al., 1993a) and prevailingNW dispersion, reached a distance greater than 20 km from the vent(Rolandi et al., 1993a; Mastrolorenzo et al., 2006; Sulpizio et al., 2008-this issue). The Avellino eruption has been dated by over 20 14C agedeterminations on proximal areas. This abundance arises from itsimportance in both the local and Mediterranean archaeologicalstratigraphy (Albore Livadie, 1994). However, many determinationswere obtained some time ago on paleosols (e.g. Alessio et al., 1974) or


on tree trunk remains (Marzocchella et al., 1994). Some more recentlydetermined ages (Vogel et al., 1990; Southon et al., 1994; Terrasi et al.,1994) refer to samples collected from deposits that are dubiouslycorrelated with the Avellino eruption. The samples collected atPozzelle Quarry (Vogel et al., 1990; Southon et al., 1994; Terrasi et al.,1994) cannot be related to the Avellino eruption. This was alreadynoted by Rolandi et al. (1998), and was confirmed by repeated fieldsurveys that unequivocally recognized the “Avellino” pyroclasticdeposits of Fig. 2 in Terrasi et al. (1994) as referring to AP2 eruption.A new 14C measure indicates maximum age older than previouslyreported (Table 1), consistent with 14C age on Pinus seeds collected justabove the layer of Avellino preserved in the Lago Grande di Monticchiorecord (3920±50 yr BP; Wulf et al., 2004; Watts et al., 1996) and withthe 14C age (3850±55 yr BP) obtained at Pian di Pecore site (60 kmSE ofVesuvius; Pantosti et al., 1993) just below deposits correlated withAvellino eruption. If we consider these three ages as the best available,they yield an averaged age of 4365±40 cal yr BP (Table 1), which mustbe considered a maximum age for the eruption.

An intense explosive activity repeatedly occurred between theeruptions of Avellino and Pompeii. By correlating more than 40stratigraphic sections around the volcano, Andronico and Cioni (2002)identified six main eruptions (AP1–AP6, and few minor interveningevents), whose deposits, in some cases, can be traced up to 20 kmfrom the vent. AP deposits resulted from two main types of eruptions:(1) weak subplinian (AP1 and AP2, “Subplinian 2” in Cioni et al., inpress), consisting of pumice and scoria fall layers and minor fine-grained, vesiculated, accretionary lapilli-bearing ashes; and (2) mixed,Violent Strombolian to Continuous Ash Emission events (AP3–AP6),which deposited complex sequences of fallout, massive to thinly

Fig. 3. Variation of Somma-Vesuvius rocks (A) and groundmass glasses (B) from the major efrom Codola, Schiava and Taurano eruptions (of uncertain age and provenance, from Diestablishment of variation fields reported in lower diagrams. In the lower glass plot, the cUndersaturated field. All analyses water-free to 100 with all Fe as FeO. Whole rock data areAndronico and Cioni (2002) and unpublished. Glass data are from Marianelli (1994), Landi edata set is available on request).

stratified, fine ash beds and minor scoria-bearing lapilli layers. Thecomposition of the ejected material changes with time, and thesechanges are strongly correlated with vent position and eruption style.A different view of the Avellino-Pompei period of activity was offeredby Rolandi et al. (1998) and Somma et al. (2001), who concluded thatthis “Protohistoric” period includes only three events formed bycomplex, Strombolian–Vulcanian deposits separated by paleosols. Theyoungest of these deposits should correspond to the sequence AP3–AP6 of Andronico and Cioni (2002), being all these depositsconsidered by Rolandi et al. (1998) as different units of the sameeruption. The ages of AP eruptions are reported in Table 1 bycorrelating available data (Vogel et al., 1990; Southon et al., 1994;Terrasi et al., 1994; Rolandi et al., 1998) to the stratigraphy ofAndronico and Cioni (2002). Themaximumage for AP1 is 3500±60 calyr BP, which is not distinguishable from the best available AP2 age,despite a thin soil sandwiched between the two deposits. The age ofthe overlying AP3 deposit is 2830±50 cal yr BP, which suggests a 5–7centuries-long AP2–AP3 rest. This long rest period is in conflict withthe absence of a soil between AP2 and AP3 deposits and with thedifference in age between AP2–AP3 found at Lago Grande diMonticchio of only ca 120 yr (Wulf et al., 2004). The final productsof this interval (AP6) were tentatively correlated by Andronico andCioni (2002) to a (dubious) historic event reported by Stothers andRampino (1983) on 217–216 B.C.

2.2.4. The Pompeii Plinian eruption and the P–XX intervalPresently, a general consensus exists on the stratigraphy of the

79 A.D. eruption deposits (Sigurdsson et al., 1985; Cioni et al., 1992),which can be once more divided into three phases (with several

xplosive eruptions within Total Alkalis vs. Silica (TAS) diagram (Le Bas et al.,1986). DataVito et al., in press) are also reported. The plot of data (upper diagrams) allows theoloured areas include the 90% of analyses; Codola glasses are included in the Slightlyfrom Joron et al. (1987), Rosi et al. (1993), Landi et al. (1999), Cioni et al. (1995, 2003),t al. (1999), Andronico and Cioni (2002), Cioni et al. (2003) and unpublished (the entire


eruption units). The opening phase, comprising only a fewcentimetresof accretionary lapilli-bearing ash fall and very minor surge beds, wasfollowed by the Plinian phase, mostly consisting of tephra fallout (2–4 km3, white and grey pumice layers, phonolitic to tephriphonolitic).This deposit is the product of a sustained Plinian column, whichduring the deposition of the grey pumice, collapsed at least four times,producing pumice and ash flows. According to Pliny the Younger'sletters to Tacitus and the chronology proposed by Sigurdsson et al.(1982, 1985), the Plinian phase of the eruption lasted no longer than20 h. It was followed by a phreatomagmatic phase whose initial stages(formation of a short-lived sustained column concluded with thegeneration of a high-energy turbulent pyroclastic flow) coincidedwith the onset of the caldera collapse that enlarged to the South theexisting depression (Cioni et al., 1999). The A.D. 79 eruption closedwith the emplacement of “wet” pyroclastic density currents and of athick succession of accretionary lapilli-bearing ash beds.

The Pompeii eruption probably left the system open, being thesubsequent 2–3 centuries punctuated by ash emission activity (the “S.Maria cycle” of Andronico et al., 1995, the “Ancient Historic” of Sommaet al., 2001) and by the initial building of a central cone within thecaldera depression. The activity ceased, possibly at the beginning ofthe IVth century, and a rest followed until A.D. 472, when the volcanoexplosively reawoke and the largest subplinian eruption of theVesuvius recent history took place, the so-called “Pollena” event(Delibrias et al., 1979). The eruption had a pulsating behaviour withalternating emplacement of pyroclastic fall and pyroclastic densitycurrent deposits (Rosi and Santacroce 1983; Rolandi et al., 2004;Sulpizio et al., 2005). These deposits, whose minimum volume hasbeen estimated at 0.4–0.5 km3, show a continuous compositional

Fig. 4. CaO vs. SiO2 and Al2O3 vs. FeO (all Fe as FeO) variation fields of whole rocks (A andexplosive eruptions. Legend as in Fig. 3. The coloured areas in B and D diagrams include theeruptions (of uncertain age and provenance). Codola glasses are included in the Slightly Unddata as in Fig. 3.

zoning from leucititic phonolite to leucititic tephriphonolite. Close tothe Pollena eruption both in time and composition of erupted pro-ducts, another subplinian event occurred in A.D. 512 (PM1 ofAndronico et al., 1995; AS1 in Cioni et al., in press). During the MiddleAge the Vesuvius cone grew discontinuously, alternating periods ofopen conduit, mild, persistent activity with lava effusions (fromVIIIth to XIIth centuries, Principe et al., 2004), repose periods, andmoderate size (V.E.I.=2–3) explosive eruptions. The pyroclastic de-posits of at least four different major eruptions (AS2 to AS5; Cioni etal., in press; “Medieval” of Rolandi et al., 1998) have been recognized inthis period.

On A.D. 1631, December 16, Vesuvius erupted suddenly (butprecursors had been conspicuous; Rosi et al., 1993; Rolandi et al.,1993c; Bertagnini et al., 2006) after a quiescent period of uncertainlength. The date of the last Vesuvius eruption prior the A.D. 1631subplinian event is unclear. Historic estimates range from A.D. 1139(preferred by Rolandi et al., 1998) to A.D. 1500 (Guidoboni and Boschi,2006). After the onset of the eruption, a high eruptive column rapidlyformed, causing lapilli fallout East of the volcano (8 h duration). Aphase of repeated strong detonations and discontinuous block and ashfallout followed until the morning of December 17, when pyroclasticflows descended the flanks of the cone and devastated several villages.

The A.D. 1631 eruption left the conduit open, and the volcanoentered its period of modern activity, characterized by semi-persistent, mild activity (small lava fountains, gases and vapouremission from the crater), punctuated byminor, summit or lateral lavaeffusions and short periods of repose (from months to a maximum of7 yr). Each of these rests was preceded by a more powerful, explosive–effusive, polyphased eruption (“Final Eruption”; Santacroce, 1987;

C) and groundmass glasses (B and D) of pyroclastic products from the major Vesuvius90% of glass analyses. C, S and T indicate plots and fields of Codola, Schiava and Tauranoersaturated Field (B and D). All analyses water-free to 100 with all Fe as FeO. Sources of

Fig. 5. The variations of Nb, Sr and Ba shown by whole rocks XRF analyses of majorexplosive eruptions of Vesuvius discriminate the three groups of rocks recognized inFig. 2, and appear peculiar for most of single eruptions. Legend is common to all plots.Note the Pompeii trend in the Sr vs. Ba plot, completely out of the “mildly silica-undersaturated” field. Sources of data as in Fig. 3.


Nazzaro, 1998; Arrighi et al., 2001), whose largest examples occurredin 1944, 1906, 1822 and, possibly, 1794.

3. Whole rock and glass compositions

The Somma-Vesuvius products display, with very few exceptions, aHigh Potassic character in the sense of Middlemost (1975), exhibitinga wide variability from nearly silica-saturated (normative nephelineb5%) to strongly undersaturated (leucite-normative). This allowedJoron et al. (1987) and Ayuso et al. (1998), coupling age and silicaundersaturation degree, to distinguish three different groups of rocks,substantially well recognizable within a classic TAS diagram (Fig. 3):1. slightly undersaturated, older than Mercato eruption; 2. mildlyundersaturated, from Mercato to Pompeii eruptions; highly under-saturated, younger than Pompeii eruption. Peculiar variations in thecontent of some major (Fig. 4) and trace elements (Fig. 5) as well asdifferent trends in element/element ratios (e.g. Th/Ta and Nb/Zr inFig. 6) are also generally consistent with this subdivision. Isotopicvariations, however relatively large (87Sr/86Sr=0.70699 to 0.70803;δ18O=7.3 to 10.2‰; 206Pb/204Pb=18.947 to 19.178; 207Pb/204Pb=15.617to 15.769; 208Pb/204Pb=38.915 to 39.435; 143Nd/144Nd=0.51228 to0.51251, Ayuso et al., 1998 and references therein) do not contribute tothe characterization of the three groups.

Previous papers (Civetta and Santacroce, 1992; Santacroce et al.,1994; Cioni et al., 1997) have shown that the high variability ofVesuvius magmas resulted (at least for the last 4 ka) from magmaevolution processes reflecting irregularly spaced periods of open andobstructed conduit conditions of a plumbing system characterizedby the constant presence of shallow magma chambers, periodicallysupplied by discrete, deep, mafic magma batches. The compositionalspectrum of these batches has been investigated through meltinclusions in high-T (mostly olivine and diopside) crystals (Marianelliet al., 1995), revealing their not truly primitive nature. A change fromK-basaltic to K-tephritic occurred between the AP1 and A.D. 79eruptions, strongly responsible for the changes recorded by highlyevolved magmas (from K-trachyte and K-phonolite to leucititicphonolite). Magma recharge to the shallow reservoirs characterizedby processes of carbonate assimilation and “mixing and minglingwith previously contaminated magmas resting at shallow depthsand/or by entrapment of crystal mush generated during previousmagma storage in the crust” has been proposed by Piochi et al.(2005) to explain the change in composition with time of Vesuviusmagmas.

The magma chambers associated with the open conduit condi-tions which characterized the last 300 years of activity (from 1631 to1944) were small, continuously tapped through persistent Strombo-lian activity, and each fresh magma pulse induced either quiet lavaeffusion or, more rarely, violent explosive–effusive, polyphasederuptions (e.g., 1906; Bertagnini et al., 1991) leading to the emptyingof the reservoir (Santacroce et al., 1993; Marianelli et al., 1999). Thelast of these events in 1944 led to the obstruction of the conduit andthe end of the persistent activity of Vesuvius. Direct ascent of maficmagma from the depth was suggested by Pappalardo et al. (2004) tohave fed the activity of the period 1805–1944. During periods ofobstructed conduit, magma chambers formed and grew until, afterquiescent intervals of variable length, an explosive eruption wasinitiated. Cioni et al. (1997) argued that Vesuvius chambers have haddifferent volumes, ages and layering, from early, small (0.01–0.1 km3),high aspect ratio, hosting nearly homogeneousmafic melts, tomature,large (N1.0 km3), low aspect ratio, hosting layered magma bodies withstepwise gradients between lower, convective and upper, stratified,felsic portions. The possibility of producing the extremely evolvedcompositions characterizing the large chambers solely results fromthe repeated refilling of the chambers, inducing the “incompatiblebehaviour” of alkalis (mainly K) over a compositional range muchwider than in a closed-system equilibrium fractionation. As a con-

sequence of the refilling, the temperature of extensive K-feldsparcrystallization (~900 °C) is reached at very high alkali concentrations.

The large variability of magmatic processes responsible of magmaevolution have resulted in a large variation of groundmass glasscomposition of the erupted products, and must be taken in accountwhen considering the microanalytical data for tephra correlationstudies. Whole rock and glass compositions are presented anddiscussed in the following sections, particularly focussed on theproducts of 17 eruptions with VEIN3 (14 from Somma-Vesuvius, 3 ofuncertain source), the most likely to be found as distinct beds in distalarchives.

Fig. 6.Whole rock Th vs. Ta (INAA analyses) and Nb vs. Zr (XRF analyses) plots of the major explosive eruptions of Vesuvius. Legend refers to both diagrams (note that Th–Ta data arenot available for A.D. 512 products). Sources of data as in Fig. 3.


3.1. Strongly silica—undersaturated magmas

This group comprises all the products erupted after the A.D. 79Pompeii eruption. For tephra correlation studies, however, only thethree largest-intensity eruptions of the period are discussed here: A.D.1631, 512 and 472 “Pollena”. The most relevant common geochemicalsignatures of these rocks concern their lower silica and higher alkalicontents with respect to rocks with comparable evolution from theother two groups, as well as their (especially Pollena) very high Sr andBa contents (Fig. 5). These features are consistent with evolutionarytrends (mostly fractionation within a periodically supplied magma

Fig. 7. Element vs. element plots of whole rocks (dots, XRF analyses) and glasses variation fieThe coloured fields include the 90% of glass analyses (number of quoted analyses in the legenmedieval age (around the 1000 A.D.), typical for themafic nature of most eruptedmagmas, arand Ti contents close to “medieval” field (fresh deep magma?). All analyses water-free to 10

chamber) of K-tephritic liquids dominated by crystallization of leuciteand mafic minerals, and characterized by minor role of plagioclaseand the absence of K-feldspar fractionation. Fig. 7 compares the majorelements whole rock and glass variations as a function of CaO shownby the products of the three eruptions.

3.1.1. A.D. 472 “Pollena”The products exhibit an almost continuous compositional variation

from initially erupted leucititic phonolite to later erupted leucititicphonotephrite (Rosi and Santacroce, 1983; Rolandi et al., 2004;Sulpizio et al., 2005). Pumice and scoria from proximal sections are

lds (mostly ETS analyses) from the main explosive eruptions of the post A.D. 79 period.d). Few unpublished analyses of glass from pyroclasts of an eruption (PM4 in Table 1) ofe also reported. Note the presence of (few) 1631 and 512 glass fragments with high Ca, Fe0 with all Fe as FeO. Sources of data as in Fig. 3.


variable in phenocryst content (6–27% by volume, vesicle free) and arecharacterized by a microlite-rich groundmass. The phenocryst assem-blage is dominated by leucite and clinopyroxene along the entirestratigraphic sequence, with minor sanidine and davyne. Amphiboleand garnet are only present in the very basal, pumice-bearing samples.Syneruptive mixing phenomena were moderate and never involvedliquids with strongly contrasting temperatures and compositions,leading Cioni et al. (1997) to conclude that the Pollena eruption tappeda medium aspect ratio magma chamber with an almost continuousthermal/compositional gradient. As expected, and common to allcomponents and all eruptions, the variation fields of glass are largerthan those defined by whole rocks. This is particularly evident in thecase of Pollena samples, as a probable consequence of their high crystalcontent. With decreasing CaO, in both rocks and glasses, alumina andsoda increase while Iron and Titanium decrease. The trends of wholerock and glass diverge for SiO2 and K2O, whose marked depletion inglass is the result of the high content of leucite phenocrysts in the bulkrock and leucite and K-feldspar microcrysts in the groundmass.

3.1.2. A.D. 512The deposits of a subplinian eruption immediately following the

A.D. 472 Pollena eruption have been tentatively related to anhistorical event that has been attributed to the year A.D. 512 (Cioniet al., in press). Notwithstanding the age of this eruption is still amatter of debate (Principe et al., 2004 suggest that an event of thissize should have occurred in A.D. 536, correlating the A.D. 512 eventto mild Strombolian activity), magma composition is typical of themafic “tail” of the Pollena succession. The composition of A.D. 512glass ranges in CaO between 7 and 12 wt.%, thereby overlapping theCa-rich part of the field of Pollena glass while being distinct from theA.D. 1631 magma (Fig. 7). The range of glass composition of thesedeposits is generally close to the range shown by co-magmatic wholerocks (Fig. 7).

3.1.3. A.D. 1631The composition of the scoria of the A.D. 1631 pyroclastic deposits

suggests, once more at Vesuvius, the tapping of magma from acompositionally zoned magma chamber. Leucite-bearing tephriticphonolites of the early Plinian phase (top portion of the chamber)were followed by the fallout of darker and slightly more mafic magmaricher in crystals. The composition vs. stratigraphic height shows arather regular and continuous upward increase of CaO (7–12 wt.%)paralleling increase in FeO (4.7–6.6 wt.%) and TiO2 (0.5–0.9 wt.%) anddecrease in SiO2 (52–49 wt.%), Al2O3 (21–16.5 wt.%) and alkalis (4.6–2.2 and 8.3–5.7 wt.%, for Na2O and K2O, respectively). The juvenilefragments collected from the pyroclastic flow deposits do not followthis regular trend of decreasing evolution. They exhibit in fact arandomly variable composition, expanding the variation field towardsmore evolved composition than that of the early fallout phase (CaOdown to 6wt.%; K2O and SiO2 up to 9.5 and 54 wt.% respectively). As inA.D. 472, however less markedly, the 1631 glasses show K2O depletionand Na2O enrichment. The extremely high microlite content and thehigh SiO2 (N53 wt.%) and low CaO (2–4 wt.%) contents of A.D. 1631groundmass glass represent a distinctive features within the stronglyundersaturated group.

3.2. Mildly silica—undersaturated magmas

This group consists of the pyroclastic products of three Plinianeruptions (A.D. 79 “Pompeii”, 4300 yr BP “Avellino” and 8900 yr BP“Mercato”) and at least six other explosive eruptions occurred betweenthe Avellino and Pompeii events (AP1 to AP6 of Andronico and Cioni,2002). Differently from the Mercato deposits, characterized by a strongcompositional homogeneity all along the whole eruptive sequence, theproducts of the other eruptions of this group present importantcompositional variations, from the most evolved products at the base

to the least evolved toward the top. The Mercato and Avellino eruptions(first-erupted white pumice) are characterized by the emission of themost evolved products of Somma-Vesuvius (CaOb2.0%, NbN100 ppm;ZrN700 ppm, Th up to 100 ppm). Fig. 8 compares the major elementwhole rock and glass variations as a function of CaO for all the productsof the studied eruptions.

3.2.1. A.D. 79 “Pompeii”The deposits are compositionally zoned from early phonolitic

white pumice to late phono-tephritic grey pumice. The compositionalzoning is characterized by a stepwise gradient rather than acontinuous variation. The white/grey boundary is well defined fornearly all elements, and for some chemical parameters there is amarked compositional gap between white and grey pumice (wholerock plot in Fig. 8). Both white and grey pumice contain phenocrysts ofsanidine and clinopyroxene plus minor brown mica, leucite, garnet,amphibole and plagioclase; phenocrysts content increases fromwhiteto grey pumice. Sigurdsson et al. (1990) and Civetta et al. (1991) haveshown that the compositional gradients on the grey pumice reflectsvarying degrees of mixing between twomagmas. The extent of mixingis indicated by the sanidine phenocrysts, whose composition andStrontium isotopic ratio reveal unequivocally a crystallization from“white” melts (Cioni et al., 1995), and is closely linked to magmadischarge rate. The grey pumice results therefore from variable extentof syneruptive mixing between phonolitic liquids capping thereservoir and lower “grey” melts, never erupted without beingmixed. The matrix glass of the grey pumice records the progressivetransition from physical mixing (bimodal compositions of the base ofthe grey pumice fall deposit) to chemical hybridization (a singlecompositional mode at the top). Microanalytical data on groundmassglass are in fact characterized by a bimodal distribution of majoroxides like CaO and FeO at the base of grey pumice, whichprogressively shift toward a unimodal distribution with an inter-mediate composition to the top of the sequence (Cioni et al., 1995).According to Civetta et al. (1991) and Cioni et al. (1995), the Pompeiichamber grew on a residual reservoir containing a crystal-richtephritic–phonolitic magma, not erupted during the precedingAvellino Plinian eruption, and about half of magma ejected in A.D.79 could have been inherited from pre-Avellino times. This fact andthe recorded change (from K-basalt to K-tephrite) in the compositionof deep mafic magma supplying the shallow reservoir account fordifferences and similarities recorded by the products of the twoeruptions. In Fig. 8, differently from the two-fold splitting of wholerock analyses, the Pompeii glass exhibits continuous variations in alldiagrams, with the exception of the CaO vs. Na2O plot, where the“white” and “grey” families appear separated by a relative rarefactionof analyses. Although the compositional range of glass analysesencompasses the whole rock compositional fields, the relative K2Odecrease and Na2O–Al2O3 increase characterizing most of the samplesstrongly implies a major role for K-feldspar crystallization (pheno-crystic, microlitic and cryptocrystalline) in determining the mostevolved glass compositions.

3.2.2. AP eruptionsAccording to Andronico and Cioni (2002), the six major explosive

eruptions occurred between Avellino and Pompeii (“AP”) repeatedlytapped the upper portion of a rejuvenatedmagma chamber inwhich asubstantial residual of the Avellino tephriphonolitic, hybrid “grey”magma continued to be supplied and evolved. The final stage of thisprocess is represented by the Pompeii eruption, whose “Avellinoheritage”, as already mentioned, has been invoked by Civetta et al.(1991) and Cioni et al. (1995). A normal sequence of extraction frommore evolved to less evolved material appears to be characteristic ofAP eruptions, suggesting that compositionally stratified reservoirswere tapped. The largest variability, from tephritic phonolites tophonolites, is recorded in pumice and scoria from the AP1 and AP2

Fig. 8. Element vs. element plots of whole rocks (squares, XRF analyses) and glasses variation fields (mostly ETS analyses) from themain explosive eruptions of the 8900 cal yr BP–A.D.79 period. The coloured fields include the 90% of glass analyses (number of quoted analyses in the legend). All analyses water-free to 100with all Fe as FeO. Sources of data as in Fig. 3.


members. Fig. 8 shows that the recognition of distinctive APgeochemical features is not obvious for both whole rocks and glasses.A possible suggestion could concern the generally higher FeO and TiO2

contents of AP eruptions. The major elements glass compositions ofthe different AP samples show a large overlap, making difficult thedistinction of the different AP eruptions with the only aid of majorelements data (e.g. in Fig. 9).

3.2.3. 4300 cal yr BP “Avellino”The Avellino deposits resemble those of Pompeii in that they are

characterized by a discontinuous variation from early erupted phono-litic white pumice to late erupted tephri-phonolitic grey pumice.

Fig. 9. CaO vs. SiO2 and Al2O3 vs. FeO(tot) plots of whole rocks and glasses of eruptions occurreThe violet line encircles the variation fields of glass shards (all samples) while coloured areas sFe as FeO. Sources of data as in Fig. 3. (For interpretation of the references to colour in this

Avellino pumice is generally characterized by a larger crystal contentwith respect to Pompeii and AP products. Phenocryst assemblage isdominated by mm-sized sanidine, and by minor pyroxene, amphiboleand garnet. Mineral paragenesis is peculiar for the presence ofnepheline and scapolite. According to geochemical, mineralogical,melt inclusions, and isotopic data Civetta et al. (1991) and Cioni et al.(1997) interpreted the bulk rock compositional variations in terms of amagma chamber, quite similar to that of Pompeii, characterized by amain two-fold layering strongly contrasting in temperature andcomposition. The dynamics of extraction was also similar, withextensive mixing occurring throughout the second half of the eruption(emission of hybrid tephri-phonolitic grey pumice rapidly formed

d between the Avellino and Pompeii Plinian events (“AP”). Symbols refer to whole rocks.how concentration of analyses for single eruption. All analyses water-free to 100with allfigure legend, the reader is referred to the web version of this article.)


within the chamber as a consequence of syneruptive mixing) and noemission of unmixed lower magma. Besides themore evolved nature ofits white pumice, the Avellino products, compared to Pompeii, showgenerally higher Na2O (5–10 against 4–7%) and lower K2O (6–8 against8–10%) contents. Such a distinction is not evident in glass shards.Differently from Pompeii, the Avellino glass generally preserves thewhite-grey splitting of whole rocks, but, in terms of major elementscomposition, the distinction between Avellino, Pompeii and AP glassesappears not easy, the main distinctive character being the higher Al2O3

and lower CaO content of Avellino white pumice glass.

3.2.4. 8900 cal yr BP “Mercato”The stratigraphic succession of the Mercato Pumice is dominated

by the crystal-poor products of its Plinian phase (three main falloutunits and some associated pumice flow deposits accounting for morethan 90% of the total erupted volume). They have a homogeneous,poorly variable K-phonolitic composition close to that of the mostevolved Avellino white pumice (Figs. 5, 6, and 8) and plotting in theproximity of the “phonolitic minimum” of the petrogeny's residuasystem (Hamilton and Mackenzie, 1965, for PH2O of 1 kbar, in Joronet al., 1987). Owing to the puzzling concurrence of the exhaustedevolving capacity of the magma with the poorly porphyritic nature ofpumice, the Mercato glass composition shows moderate variabilityandminor differences compared to thewhole rock, mostly concerningthe slightly lower silica and higher alumina contents.

3.3. Slightly silica—undersaturated (to saturated) magmas

Two large eruptions related to Somma-Vesuvius activity occurredin the period preceding the Mercato Eruption: the subplinian,19,000 cal yr BP “Greenish Pumice” and the Plinian, 22,000 cal yr BP

Fig.10. Element vs. element plots of whole rocks (triangles, XRF analyses) and glasses variatio8900 cal yr BP, including events of uncertain source (Codola, Schiava and Taurano). The colouranalyses water-free to 100 with all Fe as FeO. Sources of data as in Fig. 3.

“Pomici di Base”. Three other eruptions occurred in the periodbetween 22 and 33 ka, from uncertain source: the Codola, Schiava andTaurano eruptions. Relatively few whole rock and glass shardscompositions are available for these eruptions, which will be alsoshown for comparison. The most relevant common geochemicalsignature of the rocks of all these eruptions, related to their K-trachytichighly evolved composition, concerns the higher silica and loweralkali contents (with respect to rocks with comparable degree ofevolution of the other two groups), as well as their moderate Sr and Bacontents (Fig. 5). The Pomici di Base and Greenish Pumice exhibit,moreover, quite similar, nearly constant, Ta/Th (0.11±0.002 for botheruptions) and Zr/Nb (7.4±0.4 for the Pomici di Base, 6.9±0.1 for theGreenish) ratios, the highest recorded in Vesuvius rocks (Fig. 6). As awhole the geochemical features of these rocks are coherent withevolutionary trends of K-basaltic liquids initially driven by crystal-lization of mafic phases and plagioclase and later involving K-feldsparfractionation. Fig. 10 compares the major elements whole rock andglass variations as a function of CaO of this group of rocks.

3.3.1. 19,000 cal yr BP “Greenish Pumice”This subplinian eruption produced a complex alternation of

pyroclastic fall and flow deposits that Cioni et al. (2003) subdividedin several eruptive units (lapilli fall, ash fall, pyroclastic flow and surge).Juvenile clasts exhibit a broad range in colour, vesicularity andgroundmass crystallinity, with extremely large density variations(400–2000 kg/m3), even in single layers. All have a low phenocrystcontent, with sanidine, amphibole, minor plagioclase, clinopyroxene,biotite and opaques, constant over the entire stratigraphic sequence.Greenish and Mercato Pumice are the only large eruptions fromVesuvius not characterized by a compositional zoning. The groundmasstexture ranges from glassy cryptocrystalline to massively crystallized,

n fields (mostly ETS analyses) from themain explosive eruptions of the period older thaned fields include the 90% of glass analyses (number of quoted analyses in the legend). All


microlite-bearing. All the samples have K-trachytic (SiO2=60–62%;Na2O+K2O=12–13%) composition, being the entire variation of bothmajor and trace elements vs. the stratigraphic height not larger than theinternal variability within each stratigraphic layer. A low variabilitycharacterizes the composition of glass shards too, with a moderateincrease of alkalis (Na2O up to 6.0%; K2O up to 10.0%) and Al2O3 (up to19.6%) and a moderate decrease of silica (down to 58%) compared towhole rocks. Both whole rock and glass compositions of GreenishPumice are mostly included within the salic variation fields of the olderPomici di Base. Distinctive features can be found in the slightly higherAl2O3 content of Greenish Pumice products (Fig. 10).

3.3.2. 22,000 cal yr BP “Pomici di Base”The Plinian fall deposits, which represents most of the magma

volume involved in the eruption, ranges from trachytic (SiO2=62–63 wt.%) to latitic (SiO2=58–59 wt.%) pumice in the lower one-third ofthe deposit, whereas the upper two-thirds of the total thicknessconsist of latitic scoria with fairly uniform composition (SiO2=54–57 wt.%) separated by a transitional bed composed of grey-greenpumice to dark-grey scoria lapilli (Landi et al., 1999). The eruptionwas closed by a phreatomagmatic final phase during which lithic-rich fall, surge and flow deposits formed, characterized by the pres-ence of shoshonitic scoria and dense black lapilli, (CaON8 wt.%, K-trachybasaltic in other possible classification; Landi et al., 1999). Mostjuvenile products are slightly silica-saturated (normative quartz up to3%), apart from the less evolved latitic and shoshonitic rocks which areslightly nepheline normative. All the products have very low contentof phenocrysts (from 4 wt.% in trachyte pumice to 1 wt.% in the latiteand shoshonite scoria), most of which are considered not inequilibrium with the host rock (Landi et al., 1999). Phenocrysts,mainly sanidine, plagioclase, clinopyroxene and amphibole, are oftenassociated in glomerophyres with interstitial glass. According to Landiet al. (1999), as a combined result of magma chamber shape (largewith low aspect ratio) and magma withdrawal dynamics (relativelyuniform mass flux), no significant pre- or syneruptive magma mixingoccurred, and the eruption consisted of a regular and gradually deepertapping of the compositionally zoned magma body. The differentcompositions of the juvenile clasts correspond to different structuresof the groundmass: microlite-free, highly vesicular, clear glass intrachyte; mildly vesicular, dark-brown glass crowded with microlites(b50–60 µm biotite and plagioclase) in latite; poorly vesicular,hypocrystalline very rich in plagioclase, clinopyroxene and biotitemicrocrysts (up to100–120 µm) in shoshonite (Landi et al., 1999). Such

Fig. 11. Total alkalis vs. silica diagram (Le Bas et al.,1986) comparing fields of Campi Flegrei a(right). Data from this paper, Peccerillo (2005) and Turney et al. (2008). Note that not all thdiagram. Data from Codola, Schiava and Taurano eruptions (of uncertain age and provenancanalyses. All analyses water-free to 100 with all Fe as FeO.

different groundmass types strongly condition glass analysis: very fewreliable data have been obtained on rock samples with SiO2 and CaOcontents respectively lower than 59% and higher than 5.5%. Wholerock–glass comparison is therefore mostly limited to themost evolvedsamples, showing increase in K2O (strong), Na2O (moderate) andAl2O3 (moderate) and decrease in CaO and FeO (as well MgO) in theglass, while SiO2 remains unchanged (Fig. 10).

3.3.3. The older trachytic eruptionsThe few compositions of major element of bulk rocks and glasses

provided for the products of these eruptions, whose knowledge ispresently poor so that the deriving indications have to be consideredquite preliminary, are from Di Vito et al. (in press). The products ofCodola eruption (3 samples available, from latite to trachyte in Fig. 2)show whole rock composition included within the Pomici di Basevariation fields, except for their higher values in Al2O3. Differentlyfrom the Pomici di Base products of similar composition (SiO2=57–60 wt.%), the Codola pumice has a glassy groundmass suitable for EDSanalyses. Glass data show a much wider variability than whole rocks.Possible geochemical diagnostic feature could be found in the highalumina contents (N19%) for CaO in the range 4–6%.

Three analyzed samples only (with few EDS analyses of their glassygroundmass) are available for the Schiava eruption. Both whole rockand glass appear quite peculiar because of their SiO2 content (64–68%), the highest recorded in the entire Neapolitan Quaternaryvolcanic area and probably making unmistakable the correlation ofunknown deposits to this eruption (see also Figs. 3 and 4).

Finally, the oldest Taurano eruption is represented by four K-trachybasaltic (shoshonitic) rock samples and a number of ground-mass glass analyses (Fig.10), whosemost peculiar geochemical featureis the poorly evolved nature of the entire data set.

A preliminary analysis of existing data suggests that the trachyticto latitic compositions of “old Vesuvius” l.s. tephra (whole rock andglass) largely coincide with that of most of pyroclastic deposits relatedto the activity of nearby Campi Flegrei (and, possibly, Ischia)volcanoes, both in terms of major (rocks and glasses, Fig. 11) or traceelements (e.g. the poorly variable Zr/Nb ratio=7.0±0.5 of the productsfrom Campi Flegrei, fully covering the Vesuvius range; Pappalardoet al., 1999). The only recognized, possibly diagnostic, recurrentgeochemical feature concerns the slightly more alkalic (phonolitictendency) composition of the Campi Flegrei products (Fig. 11), mostlyolder than Campanian Ignimbrite (39,000 cal yr BP). Mainly looking atthe numerous trachytic eruptions of the recent activity from the

nd slightly silica-undersaturated Vesuvius rocks (left, including Ischia field) and glassese Campi Flegrei rocks in the left diagram find their correspondence in glasses of righte) are also plotted. In the glass plot, the darker areas show the highest concentration of


Campanian region, as a conclusion of their paper, Turney et al. (2008)stated that “the systematic application of Wavelength DispersiveSpectrometry (WDS) on individual glass shards…. may provide moreconsistent type-data that should enable the application of discrimi-

Fig. 12. Box plots summarising the whole set of EDS glass analyses of Somma-Vesuvius tephrvariable is displayed as a line). The lines extending from each boxmark the minimum andmaindividual circles. For the two main beds of the three compositionally zoned Plinian deposanalyses water-free to 100 with all Fe as FeO. Sources of data as in Fig. 3.

nant statistical methods” (to the diagnosis of the source eruption).Actually, it is questionable that the results presented by Turney et al.(2008) strongly support such a conclusion. This mainly depends on abias in the sampling of the studied eruptions, not fully representative

a. Each box encloses 50% of the data available for each eruption (the median value of theximumvalues of the data set that fall within an accepted range. Outliers are displayed asits (Pomici di Base, Avellino Pumice, Pompeii Pumice), data are plotted separately. All


(at least for Vesuvius) of the compositional variations of the events.We agree however with the Authors that the use of multivariatestatistical analysis could play an important role in discriminatingvolcanic glass of chemically zoned eruptions of different age andsource, when based on a large, complete, dataset of the entirecompositional spectrum of proximal deposits.

4. Summary and conclusions

The chronology (calibrated 14C ages related to proximal terrestrialdeposits) and nomenclature of the major explosive eruptions ofSomma-Vesuvius have been reviewed, and indication of the preferredvalues and names was provided (Table 1). The eruptive history of thelast 22,000 years of the Vesuvius, (calibrated age of Pomici di Baseeruption) can be illustrated by referring to the four, Plinian to Plinian,chronological and stratigraphic intervals summarized in Fig. 2.

The Vesuvius rocks are, with very few exceptions, High Potassicproducts, whose K2O content and silica undersaturation increasedwith decreasing age, allowing the distinction of three groups of rocks,as already stated by Joron et al. (1987):

1. saturated to slightly SiO2-undersaturated, older than Mercatoeruption;2. mildly undersaturated, from Mercato to Pompeii eruption;3. strongly undersaturated, younger than Pompeii eruption.

As awhole, the geochemical features of bulk rocks and groundmassglasses of all the considered eruptions are coherent with crystalfractionationwithin shallowmagma chambers repeatedly supplied bymafic liquids of different composition: K-basalt for groups 1 and 2, K-tephrite for group 3 (Civetta and Santacroce, 1992; Santacroce et al.,1994; Marianelli et al., 1995; Cioni et al., 1997). Open systemcrystallization with host-rock assimilation has been advocated bysome Authors as a reliable process of magma evolution at Vesuvius(Piochi et al., 2005). The observed geochemical variations suggestprocesses dominated by either mafic phases with minor role ofplagioclase and absence of K-feldspar fractionation (strongly under-saturated rocks), or plagioclase with minor role of mafic phases withlater, heavy K-feldspar fractionation (Pomici di Base, Greenish,MercatoandAvellino). In the case of Pompeii and (most) AP eruptions, evidenceexists of the involvement of large “Avellino-type” residua withinchamber(s) supplied by tephritic magmas (Cioni et al., 1995). We canspeculate that the evolutive path followed by magma chamber fedby K-basaltic magma could lead to trachytic or phonolitic composi-tions, as a function of the duration and frequency of the deep magmasupply.

In presenting our results, we have adopted a largely conservativestrategy for glass analysis, accepting to keep the fields of glasscomposition as large as possible as derived by our set of analyses. Thisaccounts for the large compositional heterogeneity at the microscalewhich characterizes groundmass glass frommany Vesuvius eruptions,particularly accentuated by the large microlite content of many ofthese products. Although the groundmass glass analyses exhibit ageneral larger scatter than bulk rock ones, widening the compositionaloverlap between different groups, several element vs. element plots ofglass composition allow the nearly univocal recognition of the threegroups. Within each group, the recognition of the products of thedifferent eruptions based on peculiar, simple compositional para-meters is in some cases not obvious. However, Figs. 7 to 10 should helpin the diagnosis, better if coupling data on glass–bulk rock composi-tions with stratigraphic indications and description of mineralogicalparagenesis. Differently from large eruptions, mid- to small-scaleeruptions, which mainly occurred in the period after the AvellinoPumice, were characterized by a less homogeneous bulk rock andglass composition, and by the presence of clearly heterogeneousjuvenilematerial (Cioni et al., in press). Mostly in these cases, box plots

of glass compositions (Fig. 12) could provide a simple key for thesolution of the problem. In any case, correlation of these deposits byusing only compositional data is sometimes not easy, and these datashould be accompanied by an accurate description of the miner-alogical assemblage, of the lithic component and by other texturaldata on juvenile fragments.

Acknowledgements

This work is part of the ongoing research on explosive volcanicactivity of Italian volcanoes funded by the Dipartimento dellaProtezione Civile and Istituto Nazionale di Geofisica e Vulcanologiaof Italy (DPC-INGV projects, funds to R. Santacroce and R. Cioni). Themanuscript benefits of the suggestions of an anonymous reviewer andof the accurate revision of M. Dungan.

Appendix A. Analytical methods

Bulk rock samples were analyzed for major and trace elements byX-ray fluorescence (XRF) using a Philips PW 1480 spectrometer(briquetted powder samples), following the procedure of Franziniet al. (1975). In a few cases, trace elements were determined with aXRF spectrometer ARL 9400 XP (fused glass disks) at the Diparti-mento di Scienze della Terra of Pisa (Italy) after ignition at 1000 °Cfollowing the Lachance and Claisse (1995) method. Neutron activa-tion analyses (INAA) for trace elements on bulk rock samples werecarried out according to the method of Joron et al. (1997) at CEA/CNRSSaclay (France). SEM-EDS microanalysis (major elements) was carriedout on matrix glasses of pumices and glass shards using a PhilipsXL30 apparatus equipped with EDAX Genesis at Dipartimento diScienze della Terra of Pisa (Italy). Operating conditions were 20 kVand about 0.1 nA beam current. A raster area of about 100 µm2 wasused for glass analysis to reduce the light element loss. The analysesare normalized to 100 wt.% due to the EDAX software used. EDAXperformance is discussed in Cioni et al. (1997). The whole data set isavailable from the authors upon request and in the Repository datasystem of the journal.

New AMS adC data reported in Table 1 were performed atUniversity of Arizona, National Science Foundation Accelerator Facilityfor Radioisotope Analysis. Averaged adC age values have been obtainedusing the program ISOPLOT (Ludwig, 2001), and adC calibration hasbeen obtained with the last up-dated version of CalPal (Jöris andWeninger, 1998). Age calibration is now a standard procedure forcorrecting adC dates for the effect of temporal fluctuations inatmospheric adC (Reimer et al., 2004).

Appendix B. Supplementary data

Supplementary data associated with this article can be found, inthe online version, at doi:10.1016/j.jvolgeores.2008.06.009.

References

Albore Livadie, C. (Ed.), 1994. L'eruzione vesuviana delle “Pomici di Avellino” e la faciesdi Palma Campania (Bronzo Antico). Edipuglia, Bari. 1999.

Alessio, M., Bella, F., Improta, S., Belluomini, G., Calderoni, G., Cortesi, C., Turi, B., 1974.University of Rome carbon-14 Dates XII. Radiocarbon 16 (3), 358–367.

Andronico, D., 1997. La stratigrafia dei prodotti dell'eruzione di Lagno Amendolare(Campi Flegrei, Napoli). Atti Società Toscana di Scienze Naturali, Memorie, Serie A,vol. 104, pp. 165–178.

Andronico, D., Cioni, R., 2002. Contrasting styles of Mount Vesuvius activity in theperiod between the Avellino and Pompeii Plinian eruptions, and some implicationsfor assessment of future hazards. Bull. Volcanol. 64, 372–391.

Andronico, D., Calderoni, G., Cioni, R., Sbrana, A., Sulpizio, R., Santacroce, R., 1995.Geological map of Somma-Vesuvius volcano. Period. Mineral. 64, 77–78.

Arnò, V., Principe, C., Rosi, M., Santacroce, R., Sbrana, A., Sheridan, M.F., 1987. Eruptivehistory. In: Santacroce, R. (Ed.), Somma-Vesuvius, vol. 114, 8. CNR Quaderni de laRicerca Scientifica, Roma, pp. 53–103.

Arrighi, S., Principe, C., Rosi, M., 2001. Violent Strombolian and subplinian eruptions atVesuvius during post-1631 activity. Bull. Volcanol. 63, 126–150.

http://dx.doi.org/doi:10.1016/j.jvolgeores.2008.06.009


Ayuso, R.A., De Vivo, B., Rolandi, G., Seal II, R.R., Paone, A., 1998. Geochemical andisotopic (Nd–Pd–Sr–O) variations bearing on the genesis of volcanic rocks fromVesuvius, Italy. J. Volcanol. Geotherm. Res. 82, 53–78.

Bertagnini, A., Landi, P., Santacroce, R., Sbrana, A., 1991. From magmatic tophreatomagmatic activity through the flashing of a shallow depth hydrothermalsystem: the 1906 eruption of Vesuvius. Bull. Volcanol. 53, 517–532.

Bertagnini, A., Landi, P., Rosi, M., Vigliargio, A., 1998. The Pomici di Base plinian eruptionof Somma-Vesuvius. J. Volcanol. Geotherm. Res. 83, 219–239.

Bertagnini, A., Cioni, R., Guidoboni, E., Rosi, M., Neri, A., Boschi, E., 2006. Eruptionearly warning at Vesuvius: the A.D. 1631 lesson. Geophys. Res. Lett. 33, L18317.doi:10.1029/2006GL027297.

Bocchini, D., Principe, C., Castradori, D., Laurenzi, M.A., Gorla, L., 2001. Quaternaryevolution of the southern sector of the Campanian Plain and early Somma-Vesuviusactivity: insights from the Trecase 1 well. Mineral. Petrol. 73, 67–91.

Capaldi, G., Gillot, P.Y., Munno, R., Orsi, G., Rolandi, G., 1985. Sarno Formation: the majorplinian eruption of the Somma-Vesuvius. IAVCEI 1985, Scientific Assembly, Giardinidi Naxos.

Cioni, R., Marianelli, P., Sbrana, A., 1992. Dynamics of the A.D. 79 eruption: stratigraphic,sedimentologic and geochemical data on the successions of the Somma-Vesuviussouthern and eastern sectors. Acta Vulcanol. 2, 109–124.

Cioni, R., Civetta, L., Marianelli, P., Metrich, N., Santacroce, R., Sbrana, A., 1995.Compositional layering and syneruptive mixing of a periodically refilled magmachamber: the A.D. 79 plinian eruption of Vesuvius. J. Petrol. 36, 739–776.

Cioni, R., Marianelli, P., Santacroce, R., 1997. Thermal and compositional evolution of theshallow magma chambers of Vesuvius: evidence from pyroxene phenocrysts andmelt inclusions. J. Geophys. Res. 103, 18277–18294.

Cioni, R., Santacroce, R., Sbrana, A., 1999. Pyroclastic deposits as a guide for recon-structing the multi-stage evolution of the Somma-Vesuvius caldera. Bull. Volcanol.60, 207–222.

Cioni, R., Levi, S., Sulpizio, R., 2000. Apulian Bronze Age pottery as a long distance indicatorof the Avellino Pumice eruption (Vesuvius, Italy). In: McGuire, W.G., et al. (Ed.), TheArchaeology of Geological Catastrophes. Geol. Soc. Spec. Publ., vol. 171, pp. 159–177.

Cioni, R., Sulpizio, R., Garruccio, N., 2003. Variability of the eruption dynamics duringa Subplinian event: the Greenish Pumice eruption of Somma-Vesuvius (Italy).J. Volcanol. Geotherm. Res. 124, 89–114.

Cioni, R., Bertagnini, A., Santacroce, R., Andronico, D., in press. Explosive activity anderuption scenarios at Somma-Vesuvius (Italy): towards a new classification scheme.J. Volcanol. Geotherm. Res. doi:10.1016/j.jvolgeores.2008.04.024.

Civetta, L., Santacroce, R., 1992. Steady state magma supply in the last 3400 years ofVesuvius activity. Acta Vulcanologica, vol. 2. Marinelli, pp. 147–152.

Civetta, L., Galati, R., Santacroce, R., 1991. Magma mixing and convective compositionallayering within the Vesuvius magma chamber. Bull. Volcanol. 53, 287–300.

Civetta, L., Orsi, G., Pappalardo, L., Fisher, R.V., Heiken, G., Ort, M., 1997. Geochemicalzoning, mingling, eruptive dynamics and depositional processes—the CampanianIgnimbrite, Campi Flegrei caldera, Italy. J. Volcanol. Geotherm. Res. 75, 183–219.

Delibrias, G., Di Paola, G.M., Rosi, M., Santacroce, R., 1979. La storia eruttiva delcomplesso vulcanico Somma Vesuvio ricostruita dalle successioni piroclastiche delMonte Somma. Rend. Soc. Ital. Mineral. Petrol. 35, 411–438.

De Vivo, B., Rolandi, G., Gans, P.B., Calvert, A., Bohrson,W.A., Spera, F.J., Belkin, H.E., 2001.New constraints on the pyroclastic eruptive history of the Campanian volcanic plain(Italy). Mineral. Petrol. 73, 47–65.

Di Renzo, V., Di Vito, M.A., Arienzo, I., Carandente, A., Civetta, L., D'antonio, M., Giordano,F., Orsi, G., Tonarini, S., 2007. Magmatic history of Somma-Vesuvius on the basis ofnew geochemical and isotopic data from a deep borehole (Camaldoli della Torre).J. Petrol. 48 (4), 753–784.

Di Vito, M.A., Isaia, R., Orsi, G., Southon, J., de Vita, S., D'Antonio, M., Pappalardo, L.,Piochi, M., 1999. Volcanism and deformation since 12,000 years at the Campi FlegreiCalderas (Italy). J. Volcanol. Geotherm. Res. 91, 221–246.

Di Vito, M.A., Sulpizio, R., Zanchetta, G., D'Orazio, M., 2008. The late Pleistocene pyroclasticdeposits of the Campanian Plain: new insights into the explosive activity ofNeapolitanvolcanoes. J. Volcanol. Geotherm. Res.177, 19–48. doi:10.1016/j.jvolgeores.2007.11.019.

Franzini, M., Leoni, L., Saitta, M., 1975. Revisione di una metodologia analitica perfluorescenza-X, basata sulla correzione completa degli effetti di matrice. Rend. Soc.Ital. Mineral. Petrol. 31 (2), 365–378.

Giaccio, B., Isaia, R., Fedele, F.G., Di Canzio, E., Hoffecker, J., Ronchitelli, A., Sinitsyn, A.,Anikovich, M., Lisitsyn, S.N., 2008. The Campanian Ignimbrite and Codola tephralayers: two temporal/stratigraphic markers for the Early Upper Palaeloithic insouthern Italy and eastern Europe. J. Volcanol. Geotherm. Res. 177, 210–228.doi:10.1016/j.jvolgeores.2007.10.007.

Guidoboni, E., Boschi, E., 2006. Vesuvius Before the 1631 eruption. Eos, Trans. Am.Geophys. Union 87 (40), 417–423. doi:10.1029/2006EO400001.

Hamilton, D.L., Mackenzie, W.S., 1965. Phase equilibrium in the system NaAlSiO4

(nepheline)—KalSiO4 (kalsilite)–SiO2–H2O. Mineral. Mag. 34, 214–231.Johnston Lavis, H.J., 1884. The Geology of the Mt. Somma and Vesuvius: being a study of

Volcanology. Q. J. Geol. Soc. Lond. 40, 35–149.Jöris, O., Weninger, B., 1998. Extension of the 14-C calibration curve to ca 40,000 cal

BC by synchronising Greenland O-18/O-16 ice core records and north Atlanticforaminifera profiles: a comparisonwith U/Th coral data. Radiocarbon 40, 495–504.

Joron, J.L., Metrich, N., Rosi, M., Santacroce, R., Sbrana, A.,1987. Chemistry and petrography.In: Santacroce, R. Ed., Somma Vesuvius. CNR Quad. Ric. Sci. 114, 105–174.

Joron, J.L., Treuil, M., Raimbault, L., 1997. Activation analysis as a geological tool: state-ment of its capabilities for trace elements studies in light of long term androutine investigations and geochemical discussions. J. Radioanal. Nucl. Chem. 216,229–235.

Lachance, G.R., Claisse, F., 1995. Quantitative X-ray Fluorescence Analysis. John Wiley &Sons, Chichester. 402 pp.

Landi, P., Bertagnini, A., Rosi, M., 1999. Chemical zoning and crystallization mechanismsin the magma chamber of the Pomici di Base plinian eruption of Somma-Vesuvius(Italy). Contrib. Mineral. Petrol. 135, 179–197.

Le Bas, M.J., Le Maitre, R.W., Streckheisen, A., Zanettin, B., 1986. Chemical classificationof volcanic rocks based on the total alkali-silica diagram. J. Petrol. 27, 745–750.

Lirer, L., Pescatore, T., Booth, B., Walker, G.P.L., 1973. Two plinian pumice-fall depositsfrom Somma-Vesuvius, Italy. Geol. Soc. Amer. Bull. 84, 759–772.

Ludwig, K.R., 2001. User's manual for Isoplot/Ex version 2.2. Berkeley GeochronologyCenter Special Publication n. 1a, pp. 1–56.

Marianelli, P., 1994. La camera magmatica del Vesuvio: processi petrogenetici edinamica eruttiva. Unpubl. PHD thesis, Università di Pisa, Italy, Dipartimento diScienze della Terra, 1–206.

Marianelli, P., Metrich, N., Santacroce, R., Sbrana, A., 1995. Mafic magma batches atVesuvius: a glass inclusion approach to the modalities of feeding stratovolcanoes.Contrib. Mineral. Petrol. 120, 159–169.

Marianelli, P., Metrich, N., Sbrana, A., 1999. Shallow and deep reservoirs involved inmagma supply of the 1944 eruption of Vesuvius. Bull. Volcanol. 61, 48–63.

Marzocchella, A., Calderoni, G., Nisbet, R., 1994. Sarno e Frattaminore: evidenze dagliabitati. In: Livadie, Albore (Ed.), “L'eruzione vesuviana delle “Pomici di Avellino” e lafacies di Palma Campania (Bronzo Antico)”. Edipuglia, Bari, pp. 157–202. 1999.

Mastrolorenzo, G., Petrone, P., Pappalardo, L., Sheridan, M., 2006. The Avellino 3780-yr-B.P.catastrophe as a worst-case scenario for a future eruption at Vesuvius. PNAS 103,4366–4370.

Middlemost, E.A.K., 1975. The basalt clan. Earth Sci. 16, 337–364.Munno, R., Petrosino, P., 2007. The late Quaternary tephrostratigraphical record of the

San Gregorio Magno basin (southern Italy). J. Quat. Sci. 22 (3), 247–266.Nazzaro, A., 1998. Il Vesuvio: storia eruttiva e teorie vulcanologiche. Collana “Geofisica

dell'ambiente e del territorio”. Liguori, Roma.Newhall, C.G., Self, S., 1982. The volcanic explosivity index (VEI): An estimate of

explosive magnitude for historical volcanism. J. Geophys. Res. 87, 1231–1238.Pantosti, D., Schwartz, D.P., Valenise, G., 1993. Paleoseismology along the 1980 surface

rupture of the Irpinia Fault: implications for the Earthquake recurrence in theSouthern Apennines, Italy. J. Geophys. Res. 98 (B2), 6561–6577.

Pappalardo, L., Civetta, L., D'Antonio, M., Deino, A., Di Vito, M.A., Orsi, G., Carandente,A., de Vita, S., Isaia, R., Piochi, M., 1999. Chemical and isotopical evolution ofthe Phlegraean magmatic system before the Campanian Ignimbrite (37 ka) andthe Neapolitan Yellow Tuff (12 ka) eruptions. J. Volcanol. Geotherm. Res. 91,141–166.

Pappalardo, L., Piochi, M., Mastrolorenzo, G., 2004. The 3800 yr BP-1944 AD magmaplumbing system of Somma-Vesuvius: constraints on its behaviour and presentstate through a review of isotope data. Ann. Geophys. 47 (4), 1363–1375.

Paterne, M., Guichard, F., Labeyrie, J., Gillot, P.Y., Duplessy, J.C., 1986. Tyrrhenian Seatephrochronology of the oxygen isotope record for the past 60 000 years. Mar. Geol.72, 259–285.

Paterne, M., Guichard, F., Labeyrie, J., 1988. Explosive activity of the South Italianvolcanoes during the past 80,000 years as determined bymarine tephrochronology.J. Volcanol. Geotherm. Res. 34, 153–172.

Peccerillo, A., 2005. Plio-Quaternary Volcanism in Italy. Springer-Verlag, Berlin, pp. 1–365.Piochi, M., Ayuso, R.A., De Vivo, B., Somma, R., 2005. Crustal contamination and crystal

entrapment during polybaric magma evolution at Mt. Somma-Vesuvius volcano,Italy: geochemical and Sr isotope evidence. Lithos 86 (3–4), 303–329. doi:10.1016/j.lithos.2005.05.009.

Principe, C., Tanguy, J.-C., Arrighi, S., Paiotti, A., Le Goff, M., Zoppi, U., 2004. Chronologyof Vesuvius' activity from A.D. 79 to 1631 based on archeomagnetism of lavas andhistorical sources. Bull. Volcanol. 66, 703–724.

Reimer, P.J., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Bertrand, C., Blackwell, P.G.,Buck, C.E., Cutler, K.B., Damon, P.E., Edwards, R.L., Fairbanks, R.G., Friedrich, M.,Guilderson, T.P., Hughen, K.A., Kromer, B.,McCormac, F.G.,Manning, S., BronkRamasey,C., Reimer, R.W., Remele, S., Southon, J.R., Stuiver, M., Talamo, S., Taylor, F.W., vander Plitch, J.,Weyhenmeyer, C.E., 2004. IntCal04 terrestrial radiocarbon age calibration0–26 cal kyr BP. Radiocarbon 46, 1029–1058.

Rittmann, A., Ippolito, F., 1962. Saggi sulla stratigrafia del Somma-Vesuvio. In: Ippolito, F.(Ed.), Saggi e studi di Geologia. Neri-Pozza, Venezia.

Rolandi, G., Mastrolenzo, G., Barrella, A.M., Borrelli, A., 1993a. The Avellino plinianeruption of Somma-Vesuvius (3760 y. B.P.): the progressive evolution frommagmatic to hydromagmatic style. J. Volcanol. Geotherm. Res. 58, 67–88.

Rolandi, G., Maraffi, S., Petrosino, P., Lirer, L., 1993b. The Ottaviano eruption of Somma-Vesuvius (8000 y. B.P.): a magmatic alternating fall and flow-forming eruption.J. Volcanol. Geotherm. Res. 58, 43–65.

Rolandi, G., Barrella, A.M., Borrelli, A., 1993c. The 1631 eruption of Vesuvius. J. Volcanol.Geotherm. Res. 58, 183–201.

Rolandi, G., Petrosino, P., McGeehin, J., 1998. The interplinian activity at Somma-Vesuvius in the last 3500 years. J. Volcanol. Geotherm. Res. 82, 19–52.

Rolandi, G., Munno, R., Postiglione, I., 2004. The A.D. 472 eruption of the Sommavolcano. J. Volcanol. Geotherm. Res. 129, 291–319.

Rosi, M., Santacroce, R., 1983. The A.D. 472 ‘Pollena’ eruption, volcanological andpetrological data for this poorly know Plinian-type event at Vesuvius. J. Volcanol.Geotherm. Res. 17, 249–271.

Rosi, M., Sbrana, A., 1987. The Phlegrean Fields. Quad. Ric. Sci. 114, 1–175.Rosi, M., Principe, C., Vecci, R., 1993. The 1631 eruption of Vesuvius reconstructed

from the review of chronicles and study of deposits. J. Volcanol. Geotherm. Res. 58,151–182.

Santacroce, R. (Ed.), 1987. Somma-Vesuvius. Quaderni della Ricerca Scientifica, vol. 8,114. CNR, pp. 1–251.

Santacroce, R., Sbrana, A., eds., 2003. Geological map of Vesuvius 1:15,000 scale. SELCA,Firenze

http://dx.doi.org/10.1029/2006GL027297

http://dx.doi.org/doi:10.1016/j.jvolgeores.2008.04.024



http://dx.doi.org/10.1029/2006EO400001

http://dx.doi.org/10.1016/j.lithos.2005.05.009

http://dx.doi.org/10.1016/j.lithos.2005.05.009


Santacroce, R., Bertagnini, A., Civetta, L., Landi, P., Sbrana, A., 1993. Eruptive dynamicsand petrogenetic processes in a very shallow magma reservoir: the 1906 eruptionof Vesuvius. J. Petrol. 34 (2), 383–425.

Santacroce, R., Cioni, R., Civetta, L.,Marianelli, P.,Metrich,N., Sbrana,A.,1994.HowVesuviusworks. "Large Explosive Eruptions". Atti dei Covegni Lincei, vol. 112, pp. 185–196.

Siani, G., Paterne, M., Michel, E., Sulpizio, R., Sbrana, A., Arnold, M., Haddas, G., 2001.Mediterranean Sea surface radiocarbon reservoir age changes since the Last GlacialMaximum. Science 294, 1917–1920.

Siani, G., Sulpizio, R., Paterne, M., Sbrana, A., 2004. Tephrostratigraphy study for the last18,000 14C years in a deep-sea sediment sequence for the South Adriatic. Quat. Sci.Rev. 23, 2485–2500.

Sigurdsson, H., Cashdollar, S., Sparks, S.R.J., 1982. The eruption of Vesuvius in A.D. 79:reconstruction from historical and volcanological evidence. Am. J. Archaeol. 86,39–51.

Sigurdsson, H., Carey, S., Cornell,W., Pescatore, T.,1985. The eruptionof Vesuvius inA.D. 79.Natl. Geogr. Res. 1, 332–387.

Sigurdsson, H., Cornell, W., Carey, S., 1990. Influence of magma withdrawal on com-positional gradients during the A.D. 79 Vesuvius eruption. Nature 345, 519–521.

Somma, R., Ayuso, R.A., De Vivo, B., Rolandi, G., 2001. Major, trace element and isotopegeochemistry (Sr–Nd–Pb) of interplinian magmas from Mt. Somma-Vesuvius(Southern Italy). Mineral. Petrol. 73, 121–143.

Southon, J.R., Vogel, J.S., Nelson, D.E., Cornell, W.S., 1994. Radiocarbon dating of theAvellino eruption of Somma-Vesuvius. In: Livadie, Albore (Ed.), “L'eruzionevesuviana delle “Pomici di Avellino” e la facies di Palma Campania (BronzoAntico)”. Edipuglia, Bari, pp. 133–138. 1999.

Stothers, R.B., Rampino, M.R., 1983. Volcanic eruptions in the Mediterranean before A.D.630 from written and archaeological sources. J. Geophys. Res. 88, 6357–6371.

Sulpizio, R., Zanchetta, G., Paterne, M., Siani, G., 2003. A review of tephrostratigraphy incentral and southern Italy during the last 65 ka. Il Quaternario 16, 91–108.

Sulpizio, R., Mele, D., Dellino, P., La Volpe, L., 2005. A complex, Subplinian-type eruptionfrom low-viscosity, phonolitic to tephri-phonolitic magma: the A.D. 472 (Pollena)eruption of Somma-Vesuvius, Italy. Bull. Volcanol. 67, 743–767.

Sulpizio, R., Bonasia, R., Dellino, P., Di Vito, M.A., La Volpe, L., Mele, D., Zanchetta, G., Sadori,L., 2008.Discriminating the-longdistancedispersal offineash fromsustained columnsor near ground ash clouds: the example of the Pomici di Avellino eruption (Somma-Vesuvius, Italy). J. Volcanol. Geotherm. Res. 177, 263–276 (this issue).

Terrasi, L., Campajola, F., Petrazuolo, V., Roca, M., Romano, A., Brondi, A., D'Onofrio, M.,Romoli, R., Monito, K., 1994. Datazione con la spettrometria di massa ultrasensibiledi campioni provenienti dall'area interessata dall'eruzione delle “Pomici diAvellino”. In: Livadie, Albore (Ed.), “L'eruzione vesuviana delle “Pomici di Avellino”e la facies di Palma Campania (Bronzo Antico)”. Edipuglia, Bari, pp. 139–146. 1999.

Turney, C.S.M., Blockley, S.P.E., Lowe, J.J., Wulf, S., Branch, N.P., Mastrolorenzo, G.,Swindle, G., Nathan, R., Pollard, A.M., 2008. Geochemical characterization ofquaternary tephras from the Campanian province, Italy. Quat. Int. 178, 288–305.

Vogel, J.S., Cornell, W., Nelson, D.E., Southon, J.R., 1990. Vesuvius Avellino, one possiblesource of seventeenth century BC climate disturbance. Nature 344, 534–537.

Walker, G.P.L., 1977. Metodi geologici per la valutazione del rischio vulcanico. Attidel convegno: I vulcani attivi dell'area napoletana. Regione Campania, Napoli,pp. 53–60.

Watts, W., Allen, J.R.M., Huntley, B., Fritz, S.C., 1996. Vegetation history and climate of thelast 15,000 years at Laghi di Monticchio, southern Italy. Quat. Sci. Rev. 15, 133–153.

Wulf, S., Kraml, M., Brauer, A., Keller, J., Negendank, J.F.W., 2004. Tephrochronology ofthe 100 ka lacustrine sediment record of Lago Grande di Monticchio (southernItaly). Quat. Int. 122, 7–30.

Wulf, S., Kraml, M., Keller, J., 2008. Towards a detailed distal tephrostratigraphy in theCentral Mediterranean: the last 20,000 yrs record of Lago Grande di Monticchio.J. Volcanol. Geotherm. Res. 177, 118–132. doi:10.1016/j.jvolgeores.2007.10.009.

Zanchetta, G., Sulpizio, R., Di Vito, M.A., 2004. The role of volcanic activity and climate inalluvial fan growth at volcanic areas: an example from southern Campania (Italy).Sediment. Geol. 168, 249–260.


Age and whole rock–glass compositions of proximal pyroclastics from the major explosive eruptions...

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