Robust date for the Bronze Age Avellino eruption (Somma-Vesuvius): 3945 ± 10 calBP (1995 ± 10 calBC)
Highlights
► Lacustrine deposits in the Agro Pontino hold thin tephra layer from Somma-Vesuvius. ► Tephra layer can be unequivocally attributed to Early Bronze Age Avellino eruption. ► In tandem dating by OxCal code provides first truly robust date: 3945 ± 10 calBP. ► Late-Holocene tephrochronology of Central Mediterranean needs some revision.
Introduction
The Avellino eruption of Somma-Vesuvius was a catastrophic Plinian event of similar magnitude as the famous AD 79 eruption (e.g. Lirer et al., 1973, Rolandi et al., 1993, Cioni et al., 2000; Sulpizio et al., 2010a). In the past decade, major Early Bronze Age sites and settlements were found underneath its proximal pyroclastic deposits. Some of these are exceptionally well preserved and represent early analogues of Pompeii (e.g. Albore Livadie et al., 1998, Albore Livadie, 2002, Di Vito et al., 2009).
Several eruption phases have been recognized from the proximal deposits (e.g. Cioni et al. 2000; Sulpizio et al., 2008): an opening magmatic phase (EU1), a Plinian magmatic phase (EU2, 3 and 4) and a phreatomagmatic phase (EU5). The fallout deposits of the Plinian-type units are by far the most voluminous and comprise geochemically distinct white (EU2) and grey (EU3) well-sorted pumice fragments. The distal ‘Avellino pumice layer’ is known as an important tephrochronological marker bed for the Early Bronze Age and has been recognized in many major Late-Holocene sediment cores from central and southern Italy (e.g. from Lago di Accesa, Magny et al., 2007; Lago di Mezzano, Ramrath et al., 1999; Lago di Albano and Lago di Nemi, Calanchi et al., 1996; Lago Grande di Monticchio, Wulf et al., 2008; Sulmona Basin, Giaccio et al., 2009), the Balkans (Lake Shkodra, Sulpizio et al., 2010c) as well as in marine cores from the Adriatic Sea (see Sulpizio et al., 2008 for a recent review). It is marked by highly vesicular porphyritic pumice, a relatively large crystal content (including sanidine, pyroxene, amphibole and garnet), and a mildly SiO2-undersaturated composition showing a transition from phonolitic for earlier deposited white pumice to tephri-phonolitic for subsequently deposited grey pumice. High Al2O3 (>23 wt.%) and low CaO (≤2 wt.%) contents in glasses are distinctive features relative to glass compositions of other major eruptions of Somma-Vesuvius (e.g. Santacroce et al., 2008, Giaccio et al., 2009).
Most information concerning the age of the eruption comes from 14C dating of organic matter associated with its deposits. Nearly all 14C dates pertain to organic carbon from paleosols, more or less carbonized plant/wood remains from archaeological sites, and skeletal material of animals or humans (e.g. Passariello et al., 2009, 2010). These materials originate from proximal ash sequences with major hiatuses. Passariello et al. (2009) reviewed all published 14C ages, which range from 3360 ± 40 (Vogel et al., 1990) to 3920 ± 50 (Watts et al., 1996). Passariello et al. (2010) concluded, also based on new dates of bones of goats killed by the eruption, that this eruption dates to ‘3550 ± 20 BP, which calibrates to 1935–1880 BC (1σ)’. However, in a slightly earlier review paper on the distal tephrostratigraphy of Somma-Vesuvius, Santacroce et al. (2008) concluded that the best ages available ‘yield an averaged age of 4365 ± 40 cal yr BP, which must be considered a maximum age’. Based on this conclusion, Sulpizio et al. (2008) stated that the Avellino eruption has ‘a best estimated maximum age of 3930 ± 20 14C yr BP (4370 ± 40 cal yr BP)’.
The uncertainty on the age of the Avellino eruption might be solved by 14C dating of continuous sedimentary sequences with an intercalated Avellino pumice layer, as for example encountered in the lakes of Monticchio, the Colli Albani and Mezzano. However, 14C ages from such sequences are scarce (Sulpizio et al., 2008) and inconclusive. This is exemplified by the AMS radiocarbon dating on Abies seeds overlying the TM-4 tephra (Avellino pumice layer) in the Monticchio record, which yielded an age of 3920 ± 50 BP (4514–4159 cal BP, 2σ error range; Watts et al., 1996). According to Wulf et al. (2004), the varve-based age of the layer is 4310 BP, given as 4310 ± 220 cal yr BP in Wulf et al. (2008). These ages are considerably higher than the age published in Passariello et al. (2010), but agree with the maximum age of Sulpizio et al. (2008).
These quoted ages illustrate the somewhat confusing way in which 14C dates have been presented in the extensive literature on the tephrochronology of Somma-Vesuvius. Also, conventions regarding the use of units for reported 14C ages were not always properly applied (see also materials and methods).
In this paper, we present a new series of 14C dates obtained from lacustrine sequences with an intercalated tephra layer in the Agro Pontino, which provide a robust date for the Avellino eruption.
Section snippets
Regional setting
The Agro Pontino in Southern Lazio, Central Italy, consists of a higher complex of Pleistocene marine terraces in the SW and an elongated, low-lying graben in the NE, the Agro Pontino s.s. (see Fig. 1). This graben contains Holocene sediments that initially filled in valleys formed during the preceding Glacial, and, with ongoing sea level rise and closure of the Holocene beach ridge near Terracina, gradually expanded over the earlier Pleistocene deposits. In the central part of the graben, the
Sites and materials
In the trench at Via Migliara 44.5 (see Fig. 2a), a thin (ca 2 cm) layer of fine sandy, non-differentiated greyish-white tephra (layer 3) is intercalated in black, pyritic clay (layers 2 and 4). This clay rests on greyish, less organic and non-pyritic reduced clay (layer 1). The layers 2 and 4 are composed of very fine laminae (<0.1 mm), highly indicative for a lacustrine origin. The tephra layer (layer 3) has sharp upper and lower boundaries, lacks internal stratification, is largely composed
Results
Grain-size distributions, presented in Fig. 3, demonstrate that the tephra layers at Migliara 44.5 and Campo Inferiore only partially consist of sand-size tephra particles (24 and 32%, respectively) and that the granulometry of the sand fraction is remarkably similar, pointing to a common origin. Amounts of organic matter, carbonates, pyrite and other materials that dissolve upon the standard pretreatment employed are considerable (18 and 35% resp.), as are amounts of clay to silt-size
Discussion
We will first address the origin of the tephra layers in the context of the depositional environment, then examine the compositional match with the Avellino eruption, and finally discuss our new age constraints for this major event.
Acknowledgements
We are indebted to the Soprintendenza archeologica per il Lazio, represented by inspector dott.ssa Nicoletta Cassieri and her local collaborator dott.ssa Carmela Anastasia, for the opportunity to make stratigraphical observations in the trial trenches at Campo Inferiore di Sezze. Together with the owner of the field, Ing. Mario Gaeta from Setia Solar Park company, they very graciously facilitated the research by keeping open and pumping out the excavation trench. The authors thank H.J.
References (45)
- et al.
Archaeological and historiographical implications of recent uplift of the Peloro Peninsula, NE Sicily
Quaternary Res.
(2009) - et al.
Tephra layers in late Quaternary sediments of the central Adriatic Sea
Mar. Geol.
(1998) - et al.
Tephrostratigraphy for the last 170 ka in sedimentary successions from the Adriatic Sea
J. Volcanol. Geotherm. Res.
(2008) - et al.
The Afragola settlement near Vesuvius, Italy: the destruction and abandonment of a Bronze Age village revealed by archaeology, volcanology and rock-magnetism
Earth Planetary Sci. Lett.
(2009) - et al.
Tephra layers from Holocene lake sediments of the Sulmona Basin, Central Italy: implications for volcanic activity in Peninsular Italy and tephrostratigraphy in the central Mediterranean area
Quaternary Sci. Rev.
(2009) - et al.
Holocene climate changes in the central Mediterranean as recorded by lake-level fluctuations at Lake Accesa (Tuscany, Italy)
Quaternary Sci. Rev.
(2007) - et al.
The Somma-Vesuvius complex and the Phlaegrean fields caldera: new chronological data of several eruptions of the Copper–Middle bronze age period
Nucl. Instrum. Methods
(2010) - et al.
The Avellino plinian eruption of Somma-Vesuvius (3760 yr B.P.): the progressive evolution from magmatic to hydromagmatic style
J. Volcanol. Geotherm. Res.
(1993) - et al.
Age and whole rock-glass compositions of proximal pyroclastics from the major explosive eruptions of Mt. Somma-Vesuvius: a review as a tool for distal tephrostratigraphy
J. Volcanol. Geotherm. Res.
(2008) - et al.
Discriminating the long distance dispersal of fine ash from sustained columns or near ground ash clouds: the example of the Pomici di Avellino eruption (Somma-Vesuvius, Italy)
J. Volcanol. Geotherm. Res.
(2008)
Geochemical characterization of Quaternary tephras from the Campanian province, Italy
Quatern. Int.
The Groningen AMS facility: status report
Nucl. Instrum. Methods B
Vegetation history and climate of the last 15,000 years at Laghi di Monticchio, southern Italy
Quaternary Sci. Rev.
Tephrochronology of the 100 ka lacustrine sediment record of Lago Grande di Monticchio (southern Italy)
Quatern. Int.
Towards a detailed distal tephrostratigraphy in the Central Mediterranean: the last 20,000 yrs record of Lago Grande di Monticchio
J. Volcanol. Geotherm. Res.
Automatic AMS sample combustion and CO2 collection
Radiocarbon
Evidence of the adverse impact of the « Avellino Pumices » eruption of Somma-Vesuvius on old bronze age sites in the Campania region (Southern Italy)
Quaternaire
A First Pompeii: the Early Bronze Age village of Nola-Croce del Papa (Palma Campania phase)
Antiquity
Geological map of Somma-Vesuvius volcano
Period. Mineral.
On the occurrence of a pumice-rich layer in Holocene deposits of western Peloponnesus, Ionian Sea, Greece. A geomorphological and geochemical approach
Centr. Eur. J. Geosc.
Hydrogeological and geochemical analyses on the relationships between karst circulation and hydrothermal circuit in the Pontina Plain (Southern Latium)
Geol. Appl. Idrogeol.
Deposition models for chronological records
Quaternary Sci. Rev.
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2022, Journal of Volcanology and Geothermal ResearchRadiocarbon dating distal tephra from the Early Bronze Age Avellino eruption (EU-5) in the coastal basins of southern Lazio (Italy): Uncertainties, results, and implications for dating distal tephra
2021, Quaternary GeochronologyCitation Excerpt :The age obtained was slightly older than ages published in previous studies (Albore Livadie et al., 1998: 1880-1680 cal yr BC; Passariello et al., 2009: 1935–1880 cal yr BC) and this led to quite some scientific debate (see for example Jung, 2017). There still is no agreement on its age as is exemplified by Zanchetta et al. (2019) and by the recent study of Razum et al. (2020), in each of which both dates (Passariello et al., 2009; Sevink et al., 2011) are mentioned. This uncertainty led Alessandri (2019) to review all available radiocarbon dates connected with the eruption, of which most stem from proximal archaeological sites, but also include distal sediment sequences.
Post-depositional subsidence of the Avellino tephra marker bed in the Pontine plain (Lazio, Italy): Implications for Early Bronze Age palaeogeographical, water level and relative sea level reconstruction
2020, CatenaCitation Excerpt :However, a unique, both spatially and temporally sharply defined palaeogeographical ‘window’ can be reconstructed where distal tephra layers are regionally preserved within wetland deposits. This fortunate situation occurs in the coastal lowlands of the Agro Pontino and Fondi basin (Lazio, Central Italy), where the distal Avellino tephra (AV-tephra) marker bed (Monte Somma Vesuvius, ca. 1900 BCE; Alessandri, 2019) is preserved as a well-defined sandy tephra layer up to more than 1 cm thick in Holocene coastal wetland deposits (Sevink et al., 2011, Fig. 1). The AV-tephra layer is well-preserved in the laminar clays, peats and calcareous gyttja (whitish lake marl deposits, e.g. Bakels et al., 2015) of the more tranquil lacustrine, marshy and shallow-water deposits, in which a fluvio-deltaic and two lake systems have been recognized (Van Gorp and Sevink, 2019).