Figure - available from: Mineralogy and Petrology
This content is subject to copyright. Terms and conditions apply.
Schematic cross-section through Somma-Vesuvius, broadly based on Marianelli et al. (1995). The solid lines represent possible conduits for the eccentric and parasitic cone magmas, emanating from a chamber at ~2–3 km depth
Source publication
Parasitic and eccentric cones on the flanks and at the base of Somma-Vesuvius potentially provide information on the plumbing system of the complex. We present geochemical data for minerals, glasses and rocks from the Pollena and Cercola cones. The rocks are phonotephrites and a basaltic trachyandesite. A volumetrically dominant type contains pheno...
Similar publications
Although Tharsis is the largest volcanic province on Mars, the origin of numerous small volcanic cones in this area is not yet fully explained. The obtained distribution of parasitic cones, along with their alignment and ages allowed us to distinguish three distinct systems related to 1) Olympus Mons, 2) Tharsis Montes, and 3) Alba Mons. Because bo...
Citations
... Proximal pre-caldera deposits, exposed in the inner caldera wall or locally exhumed by quarrying the thick pyroclastic sequence accumulated on the Somma slopes, consist of lava flows coming from a summit vent and spatter and scoria products erupted from ancient lateral vents along radial fractures (e.g. Franco and Rolandi, 1979;Santacroce and Sbrana, 2003;Cioni et al., 2008;Macdonald et al., 2016;Sparice et al., 2016). In medial and distal areas three pyroclastic deposits (Schiava, Taurano and Codola; Fig. 1), occurring between the Campanian Ignimbrite (the main ...
... Numerous studies on magma evolution (e.g., Joron et al. 1987;Trigila and De Benedetti 1993;Lima et al. 1999;Raia et al. 2000;Pappalardo and Mastrolorenzo 2010) have strongly suggested that clinopyroxene (Cpx) and olivine (Ol) crystallisation and fractionation controls the evolution of parental melts at SV. Previous studies (i.e., Joron et al. 1987;Trigila and De Benedetti 1993;Marianelli et al. 1995;Cioni et al. 1998;Webster et al. 2001;Aulinas et al. 2008;Dallai et al. 2011;Macdonald et al. 2016) individually focused on narrow time intervals compared to the entire SV volcanic history. These facts have represented the major drive leading us to cover the compositions of Cpxs and Ols in several SV products younger than 40 ka. ...
Clinopyroxene and olivine are ubiquitous phases in Somma-Vesuvius (SV) volcanics and for the first time they were systematically studied in several products younger than 40 ka. In this manuscript chemical compositions (major, trace and rare earth elements) of a large set of olivine and clinopyroxene crystals from selected rock samples are presented and discussed. Fourteen pumice samples from Plinian pyroclastic deposits as well as three scoriae and eight lava samples from inter-Plinian deposits were collected. A representative number of olivine and clinopyroxene crystals (n ~ 50) were selected for each sample and analysed by electron microprobe and laser ablation inductively coupled plasma mass spectrometer, resulting in a large database, which is now available to the scientific community. All studied eruptive products contain olivine and clinopyroxene crystals spanning a wide range of compositions. Olivines show Fo content varying from 91 to 68, while clinopyroxenes display Mg# ranging from 93 to 71. In samples younger than A.D. 79, the more evolved (Mg#82–72) clinopyroxene crystals show clear Ca enrichment (~23.5–24.5 wt% CaO) with respect to those from older samples (before-A.D.79, ~23–21 wt% CaO). The results corroborate disequilibrium between olivine, clinopyroxene and the hosting melt, and an increasing role of carbonate assimilation in SV magma evolution in the last 2 ka. The database here produced is thought as a share product that makes available mineral data and can be used for further studies by researchers to investigate geochemical evolution of the SV system.
... Few pre-caldera lavas and scoria deposits attributed to eccentric vents are reported on the northern slope of Mt. Somma ( Franco and Rolandi, 1979;Santacroce and Sbrana, 2003;Cioni et al., 2008;Santacroce et al., 2008;Macdonald et al., 2016), underlying a thick sequence of Plinian deposits. The age, distribution and geochemical features of products, mainly lavas, erupted from eruptive fissures and eccentric cones after the AD 79 eruption are investigated in several papers ( Rolandi and Russo, 1989;Arrighi et al., 2001;Principe et al., 2004;Di Renzo et al., 2007;Paolillo et al., 2016) whilst no detailed data exist regarding the ancient lateral vents and their deposits. ...
... Four eccentric cones are located on the northern Mt. Somma slope, representing the oldest sector of the volcano, and have been previously reported in literature ( Franco and Rolandi, 1979;Andronico et al., 1996;Santacroce and Sbrana, 2003;Cioni et al., 2008;Santacroce et al., 2008;Macdonald et al., 2016) although never studied in detail: two in the Pollena quarry (Pollena Trocchia; PSC in Fig. 1), one in the Traianello quarry (Somma Vesuviana; TC in Fig. 1) and one in S. Maria a Castello valley (Somma Vesuviana; SMC in Fig. 1). Furthermore, we report the finding of pyroclastic deposits, we attribute to a pre-caldera eccentric vent based on their textural characteristics and stratigraphic constrain, in a disused quarry (Vitiello quarry; Ter in Fig. 1) located in Terzigno on south-eastern Vesuvius slope. ...
... In addition, our field-based study explored in detail the nature of the deposits previously described as pure effusive lavas (e.g. Macdonald et al., 2016 and previous references). Such deposits are here reinterpreted as spatter deposits having variable degree of welding, locally showing a lava-like facies with rheomorphic structures, emplaced from lava-fountaining episodes based on their textural evidences and lithofacies variations. ...
40Ar/ 39Ar ages have been measured on the older major explosive eruptions of Somma-Vesuvius volcano in Italy. These eruptions all have pumice fall, and pyroclastic surge and flow deposits. The eruptive history of Somma-Vesuvius volcano has previously been based on uncalibrated 14C ages, mostly on carbon from paleosols, reported by Delibrias and others (1979) and Sigurdsson and others (1985). These assigned ages, plus measured 14C ages, calibrated 14C ages (denoted as 14C*) and 40Ar/ 39Ar ages (all in years) are: Mercato Tuff ~8500 years 14C=8263±29, 14C*=9250±49, 40Ar/ 39Ar=9155±461, 9541±460 Verde Tuff ~15000 years 14C=14420±130, 14C*=17200±380, 40Ar/ 39Ar=18456±302 Pomici di Base ~17000 years 14C=17229±398, 14C*=20360±139, 40Ar/ 39Ar=21759±306, 21568±328 The assigned ages are from Delibrias (1979). The 14C ages (Aleisso and others, 1971, 1973, 1974, 1978) use 1sigma counting errors reported by laboratories. The uncertainty in calibrated 14C ages (above) are these reported uncertainties plus 1sigma uncertainties of the calibration curves in IntCal04 (Reimer and others, 2004). The uncertainties in 40Ar/ 39Ar ages are 1sigma errors. Pomici di Base and Mercato samples were analyzed twice. The weighted mean of plateau ages for Pomici di Base fall unit is 21,670 ± 224 years, and the weighted mean of isochron ages is 21,313 ± 408 years. The weighted mean of plateau ages for Mercato Tuff is 9348 ± 326 years, and the weighted mean of isochron ages is 9577 ± 332 years. The period of time from 0-12.4 ka used in calibrating 14C ages is based on dendrochronologically-dated tree ring samples. The calibration older than 12.4 ka is based on marine samples, primarily corals, and the marine calibrations are in dispute. The calibrated 14C ages above are based on IntCal04. Chui and others (2007) have presented another calibration based on fossil corals. In the younger part of their record, less than 30,000 years, the age difference averages less than 100 years. Aleisso and others, 1971, 1973, 1974, and 1978, University of Rome Carbon-14 Dates IX: Radiocarbon, v. 13, 15, 16, and 20. Chiu, T.C., Fairbanks, R.G., Cal, L., and Mortlock, R.A., 2007, Analysis of the atmospheric 14C record spanning the past 50,000 years derived from high-precision 230Th/234U/238U, 231Pa/235U, and 14C dates on corals: Quaternary Science Reviews, 26:18-36. Delibrias, G., DiPaola, G.M., Rosi, M., and Santacroce, R., 1979, La Storia Eruttiva Del Complesso Volcanico Somma Vesuvio Ricostruita Dalle Successioni Piroclastiche Del Monte Somma; Rendiconti Societa Italiana di Mineralogia e Petrologia, 35:411-438. Reimer, P.J.and others, 2004, IntCal04 Terrestrial Radiocarbon Age Calibration, 0-26 Kyr BP: Radiocarbon, 46:1029-1058. Sigurdsson, H., Carey, S., Cornell, W., and Pesdatore, T., 1985, The Eruption of Vesuvius in A.D. 79, 1985: National Geographic Research, 1:332-387.
The Osservatorio Vesuviano (OV) is the oldest volcano observatory in the world having been founded in 1841 by the King of the Two Sicilies Ferdinand II of Bourbon. The historical building, located on the western slope of Vesuvius, hosts a museum with important collections of remarkable scientific, historical and artistic value, including pioneering instruments, rocks and minerals, photos and films of Vesuvius’ eruptions and many other memorabilia. Visitors discover this heritage through permanent exhibitions, and a multimedia path, across the history of Vesuvius and the origin of volcano monitoring. The museum lies within the protected area of Vesuvius National Park, established in 1995. The park’s network of trails allows visitors to enjoy the geodiversity of Somma-Vesuvius, whose activity has been intertwined with that of humans from Bronze Age to modern times, as testified by many important archaeological sites around the volcano, the most famous among them being Pompeii and Herculaneum. The “Grand Tour” was the cultural journey undertaken in the eighteenth century by European intellectuals, in which Italy was an essential destination; we consider the Museum of the OV an essential stop in a modern “Vesuvius Grand Tour”, a journey through the geological and archaeological heritage of Vesuvius territory. Since 2001, the OV is the Naples section of the Istituto Nazionale di Geofisica e Vulcanologia (INGV), which is primarily tasked with monitoring the three active volcanoes of the Neapolitan area—Vesuvius, Campi Flegrei and Ischia—through an advanced surveillance network.
We investigated helium isotopes on gas extracted by crushing from melt and fluid inclusions in minerals from Plinian and inter-Plinian tephra and lavas of Vesuvius, Italy. Erupted products of different ages were considered, from Avellino eruption (1995 BCE) to the last eruption of 1944, with special focus on the 79 AD Plinian eruption. H e / H e 4 3 ratios between 1.5 and 2.7 R A were measured, with the highest values associated with rocks representative of the roof and the walls of the magma chambers (cumulates). Lowest values occurred in sanidines representative of magma-skarn interfaces. Noteworthy, the highest measured values of the 79 AD pumices were comparable with both lavas and tephra emitted from flank vents and under open-conduit conditions during the Medieval Period and Present Period of Vesuvius activity, and present-day fumarolic discharges. H e 3 / H e 4 values are buffered within an extended, deep-seated reservoir at about 10 km filled with magma rising from the mantle. A fact that might potentially limit the accuracy of future eruption forecasting through monitoring of H e / H e 4 3 changes in Vesuvius fumaroles. Ageing and interaction with crustal rocks emerged as possible mechanisms that lowered the H e / H e 4 3 ratio of the melt during its intra-crustal magma chambers stay, with highest values associated with more dynamic conditions.
Pre-caldera (> 22 ka) lateral activity at Somma-Vesuvius is related to scoria- and spatter-cone forming events
of monogenetic or polygenetic nature. A new stratigraphic, sedimentological, textural and lithofacies investigation
was performed on five parasitic cones (Pollena cones, Traianello cone, S. Maria a Castello cone and
the recently found Terzigno cone) occurring below the Pomici di Base (22 ka) Plinian products emplaced
during the first caldera collapse at Somma-Vesuvius. A new Ar/Ar age of 23.6 ± 0.3 ka obtained for the Traianello
cone as well as the absence of a paleosol or reworked material between the S. Maria a Castello cone
and the Pomici di Base deposits suggest that such cone-forming eruptions occurred near the upper limit of
the pre-caldera period (22–39 ky). The stratigraphy of three of these eccentric cones (Pollena cones and Traianello
cone) exhibits erosion surfaces, exotic tephras, volcaniclastic layers, paleosols, unconformity and paraconformity
between superimposed eruptive units revealing their multi-phase, polygenetic evolution related
to activation of separate vents and periods of quiescence. Such eccentric cones have been described as composed
of scoria deposits and pure effusive lavas by previous authors. Lavas are here re-interpreted as welded
horizons (lava-like) composed of coalesced spatter fragments whose pyroclastic nature is locally revealed by
relicts of original fragments and remnants of clast outlines. These welded horizons show, locally, rheomorphic
structures allowing to define them as emplaced as clastogenic lava flows. The lava-like facies is transitional,
upward and downward, to less welded facies composed of agglutinated to unwelded spatter horizons in
which clasts outlines are increasingly discernible. Such textural characteristics and facies variation are consistent
with a continuous fall deposition of Hawaiian fire-fountains episodes alternated with Strombolian phases
emplacing loose scoria deposits. High enrichment factor values, measured in the scoria deposits, imply the
ejection of large proportion of ash even during Strombolian events.
The Campania Province (about 0.2 Ma to 1944 AD) consists of stratovolcanoes and multi-centre volcanic complexes (Vesuvio, Campi Flegrei, Procida-Vivara, Ischia) that are built up by mafic to felsic alkaline potassic magmas. Leucite-bearing ultrapotassic rocks are restricted to Somma-Vesuvio. Older lavas (about 2 Ma) with calcalkaline affinity are buried beneath the Campanian Plain. The rocks of the Campania Province define various suites that were generated by polybaric fractional crystallisation, mixing and assimilation of different types of wall rocks, starting from trachybasalt parents. The leucite-bearing rocks of Vesuvio also derive from trachybasalt, but extensive carbonate assimilation induced strong silica undersaturation and crystallisation of leucite. Therefore, primary ultrapotassic magmas, such as those occurring in the Roman Province, seem to be lacking in Campania. In contrast, there is a strong geochemical similarity between Campania and Stromboli, Aeolian arc. Petrological and geochemical data, therefore, argue against the commonly held view that the Campania volcanoes represent the southern extension of the Roman Province and rather indicate they represent the northernmost end of the eastern Aeolian arc. The Campania and Stromboli rocks have intermediate OIB-arc geochemical signatures, which suggest melt generation in a hybrid source, containing both OIB and subduction components. The arc-type components have been provided by fluids released by the subducted Ionian oceanic slab and associated sediments. The OIB-type component is attributed to the inflow of asthenospheric mantle from the foreland onto the subducting and southeastward retreating Ionian slab. Migration of asthenospheric mantle was favoured by opening of a slab window along the Apulian-Ionian plate.
