A. Fiorentino: The potential of nannofossils for archaeology.... , p. 101 - 103.

Journ al of Nannoplankton Resea rch , 20, 2, 199 8.

THE POTENTIAL OF NANNOFOSSIL ANALYSIS APPLIED TO
ARCHAEOLOGICAL STUDIES: THE CASE OF THE RIACE'S
BRONZESAndrea Fiorentino, via Tacito, 41-00193 Roma, Italy
Abstract: The analysis of nannofoss il assemblages has rardy been used in the study of art-work s in thepast but, recently, the situation has improved. In this context, the nannofossil content of the castingmaterial of the Riace bronze statues was examined in order to locate its provenance and to attempt toidentify sites of quarrying. Due to the limited amount of sa mple material that could be collected frominside the statues, nannofossil s were of fundamental relevance in the assignment of ages to th e materiaLand more so because no other stratigraphically-meaningful fossi ls were recovered.
A decently preserved, Upper Paleocene assemblage was found in one of the statues, which allowed areasonable hypotheses on provenance to be drawn up . The verification that nannofoss ils could survive
the melting process, a nd that the high temper at ures did not affect their preservation, is important.
Therefore, they are very promising for future application in the analysi s of archaeological remains.

Introduction
Two Greek bronze statues, known as the Riace' s bronzes,
were recovered some twelve years ago from the Ionian Sea
off the coast of Calabria, southern Italy. The statues havebeen undergoing major restoration for almost two years.
All kinds of analyses have been performed during thiswork, including the study of the palaeontolo.gical contentof the casting material. This was aimed at the age
determination of the material, in order to locate its area oforigin. The analysis of nannofossil assemblages has rarely
been used in the study of art-works in the past but, in thelast few years, this situation has improved (Svabenick~\ ,1993; von Salis, 1995; von Sa1is &Piather, 1995; Yergerio&Meggiolaro, 1995; Meggiolaro et al., 1997; Quinn et al. ,1998, this volume).
The casting material is the material used to makethe melting cast. Clay is preferably used for this purpose.
It constitutes the inside of the model and is covered bywax. Once the wax is modelled, it is also covered by castingmaterial, with a hole left at the top and a hole at the bottom.
The melted bronze is then poured through the upper hole.
It melts and replaces the wax, which flows out through thelower hole. When the bronze has solidified, the outer coveris removed. The inside of the statue is then emptied throughthe lower hole, however, it is notpossible to remove all of thematerial, so that small remnants ofcasting material can still be foundattached to the inner surface of thestatue (Figure 1). This material is theobject of the present study and,
where nannofossils were detected,
was used to trace possible
quarrying sites. Some ofthe material
contains reasonably well -preserved
nannofossil assemblages, allowing
for a coarse age-determination.

Figure 1: Representation of the remnant s of the casting material inside the Riace 's bronzes(shaded) and location of the samples collected from Statues A and B.

101

Methods
The Riace 's bronzes have been
distinguished as Statue A andStatue B for study purposes (Figurel ). Samples were collected from theresidual casting material inside thetwo statues, at the levels indicatedin Figure I , by means of amechanical ann inserted throughone of the hol es. Slides wereprepared from dilute suspensions
made from very small fragments ofthe samples. They were observedwith the light microscope at xl250
magnification.
The analysis carried out wasexclusively qualitative, according to
the scope of the work and the type

Journal of Nannoplankton Research, 20 , 2, 1998.

A. Fiorentino: The potential of na nnofoss ils for archaeology..... , p. 101 - 103.

STATUE B

STATUE A
CRETACEOUS TAXATERTIARY TAXA

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pof material. Nannofossil species are reported only aspresent or absent (Figures 2a, 2b). Preservation is mainlypoor so that some forms could be identified only to thegeneric level.
Samples are stored at the Instituto Centrale delRestauro in Rome (sample nwnbers for Statue A: US 2012,US2049, US 2050, US2088, US 2162, US2180, US 2210, US2216, us 2218, us 2240, us 2243, us 2261 , us 2264, us2278, US 2285; Statue B : US 19, US 97, US 118, US 397, US
401 , us 413, us 451, us 486, us 547, us 553, us 572, us589, US623 , US677).
Results
The samples examined are mainly clays (Lombardi et al. , inpress): in Statue A, a higher content of silty to sandy grains
is present. The samples were mostly incoherent, either
because this had been their original state or because they
had to be scratched to be collected. Only in a few cases
was it possible to obtain small grains of material, but evenin those cases the particles used to prepare the slides could
not be taken from a fresh surface. Contamination between
the samples could not be prevented both because of theway in which the material had been handled originally, andbecause of the way the samples were collected.
The results are consistent for each statue: Statue B
yielded the better-preserved material , with a diverse
assemblage and a consistent composition, whereas Statue
A presented a chaotic assemblage with forms of different
ages occurring sporadically in the samples. However, it
was possible to define the assemblages in order to relatethem to a limited number of possible quarrying locations.
The material used for the two statues has different
origins, as confirmed by the chemical analysis (Lombardiet al., in press). The Statue B material was dated as Late
• Paleocene to Early Eocene, the nannofloras mainly formedby solution-resistant and long-ranging taxa (Figure 2a),and which were evidently also resistant to the hightemperatures reached during the melting process (i.e.
Coccolithus pelagicus, Discoaster spp., Ericsonia cava,

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us 2012Figure 2a: l'r~s ~nc~' absence of nannofoss ol spe~i.:s 111 t h~ samp l ~sfrom Statue B. P = present.

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Figur·c 2b: l'r~ s~nc.: , abs~nc~ of nann oloss d speci~s in the samples
from Statue A. P = present.

Jvfarkalius inversus, A1icula decussata, Towe ius spp.,
Watznaueria barnesae). Some Paleocene zonal markers arealso present: Chiasmolithus danicus. Cruciplacolithus
primus, C. tenuis, Discoaster mohleri, D. multiradiatus,
Fascicu lithus tympaniformis, He liolithus kleinpellii, H.
riedelii, but it is difficult to determine if the material comesfrom a specific zone (or zones) because, due to poor
preservation, a younger age cmmot be excluded. Reworked
forms are also abundant, comprising among others mainly
soluti on-resistant Cretaceous taxa which are often
recovered in t11e Paleocene: Acuturris scotus,
Arkhangelskiella cymbiformis, Biscutum constans,
Cribrosphaerella ehrenbergii, Eiffellithus turriseiffelii,
Glaukolithus compactus (= Zeugrhabdotus bicrescenticus of some authors), Microrhabdulus decoratus, M icula
decussata, Jvf. murus, Jvf. praemurus, Nannoconus sp. ,Prediscosphaera cretacea , Stradneria crenulata ,fVatznaueria barnesae . Reworking witl1in the Paleocene
was observed as well (i.e. Cruciplacolithusprimus and C.
tenuis). It could well be that material of different ages wasassembled by the workers who contributed to the makingof the statues, although this does not seem to be the casefor the reworked Cretaceous taxa: these are Campanian or
Maastrichtian species that it is not unusual to find in thePaleocene.
It is possible to imagine that the material used forStatue B was collected in large quantities, and that a
specific nannofossil zone cannot thus ~e identified, unless
it was to crop out with a relevant thickness in the area oforigin. On the base of the uniformity of the assemblages,
the material seems to come from a unique area: thegeographical indication obtained is based on markers thatcharacterise fairly widespread, low-latitude assemblages.

102

A. Fiorentino: The potential of nannofossils for archaeology.. .. ., p. 10 I - 103.

On the other hand, Statue A did not yield consistentassemblages (Figure 2b ). Species occur sporadically in thesamples and are very poorly preserved. They are also
typical of low-latitude assemblages , but theirstratigraphical distribution ranges from the Early
Cretaceous (e.g. Conusphaera mexicana, Nannoconusspp.) to the Paleogcne (e.g. Ericsonia robusla, Fasciculilhus spp., Toweius spp.), without any indication ofspecific nannofossil zones. These specimens are so poorlypreserved that they cam10t provide even a remotely reliableage, and occur so sporadically (or do not occur at aiL as insample US 2050), that contamination cannot be excluded
as a reason for their presence. In fact , there were many
chances for contamination to have occurred during thehandling, collection and storage of the material , and thepreparation process.
Conclusions
The nannofossil analysis tentatively revealed that thesefossils survived the high temperatures reached during themelting process. They are generally present in the typesof clays used as casting material , and arc thus very
promising as a tool for future application in an>haeologicalstudies focused on bronze statues.
The nannoOoras contributed, together with themineralogical and chemical results , to the distinction
between the material used to make the Riace's bronzes Aand B. This distinction also corresponds to a difference inthe time of their realisation, of some tens of years (Torelli,1986).
Age determination , uniquely based onnannofossils, was essential in defining the casting material,

Journal of Nannop lankton Research , 20, 2, 1998.

in order to locate its area of provenance, which hasconsequently been identified as being the environs ofArgos (southern Greece), where Paleocene-Eocene clays
crop out.

Rcfl·n·nns
Lombardi, G. , Bianche!ti . P.L. & Yita le, M . In press. Le terre difu sione dei Bronzi di R iace. Bol/euino d 'arte.
Meggiolaro, V , Molin, G.M., Pappalardo, U . & Vergerio, P.P.
1997. Contribution to studies on roman wall painting
materia ls and techniques in Greece. Corinth , the Southeast
Bui ldin g. Proceedings of the International Workshop on
Roman Wall Painting, f<ribourg (CH), 7-9 March 1996: 105118.
Quinn , P.S. , Alaimo , R. & Montana , G . 1998. Calcareousnannofoss il ana lysis of ceramics and probable raw materials
from a n ancient Punic kiln site on the island ofMozia. western
Sicily. Journal of Nannoplankton R esearch, 20(2): thisvolume.
Sali s, K . von 1995 . Calcareous nannofossils in the arts. Joumalof Nwmoplankton Research , 17(2): 88-89 .
Sal is, K. von & Plathcr, U. 1995. Analyses of fossil coccoliths inchalk grounds of medieval art in Norway. Acta ad arclweologiam et artium historiam pertinentia , XI: 145-155.
Svabenickl\, L. 1993 . Maastrichtian nannotossils in the materialof the High Gothic paintings in Bohemia. INA Newsletter ,15(2): 96-97.
Torelli, M. 1986. La provenienza - The provenience. Universitadegli studi della Calabria. Studi e rieerche, , Gii eroi venuti dalmare", a eura di L.M . Lombardi Satriani e M . Paoletti .
Gangemi ed itore, 97-120.
Vergerio, P.P. & Meggio laro , V 1995. 1 materiali lapidei delprospetto prineipale del Palazzo deii ' Annunziata in Sulmona(AQ). P linius, 14: 302-304.

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