Punic Amphoras Found at Corinth, Greece: An Investigation of Their Origin and Technology
Author(s): Y. Maniatis, R. E. Jones, I. K. Whitbread, A. Kostikas, A. Simopoulos, Ch. Karakalos,
C. K. Williams, II
Source: Journal of Field Archaeology, Vol. 11, No. 2 (Summer, 1984), pp. 205-222
Published by: Boston University
Stable URL: http://www.jstor.org/stable/529354
Accessed: 08/09/2010 09:23
Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at
http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless
you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you
may use content in the JSTOR archive only for your personal, non-commercial use.
Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at
http://www.jstor.org/action/showPublisher?publisherCode=boston.
Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed
page of such transmission.
JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of
content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms
of scholarship. For more information about JSTOR, please contact [email protected].
Boston University is collaborating with JSTOR to digitize, preserve and extend access to Journal of Field
Archaeology.
http://www.jstor.org
.
PunicAmphorasFoundat Corinth,Greece:an
Investigationof TheirOriginand Technology
Y. Maniatis
R. E. Jones
I. K. Whitbread
A. Kostikas
A. Simopoulos
Ch. Karakalos
C. K. Williams, II
Physics Department, Nuclear Research Center Demokritos, Athens, Greece
Fitch Laboratory, British School at Athens
Corinth Excavations, American School of Classical Studies at Athens
Amongthe large depositof amphorasof the 5th centuryB.C. found in a recentlyexcavatedbuildingat ancientCorinth,Greece, were manyof Punic
type, whichthe excavatorassociatedwith the remainsin the same building
of filletedfish. Theseamphoraswere of ratheruniformshape, and yet they
exhibiteda wide range of colors and textures.Thepresentpaper, beginning
witha descriptionof the amphorasin hand specimen,reportsthe characterizationof the amphorasby six techniquesof physico-chemicalanalysis that
has yielded informationon the amphoras'technologyand origin. On the basis offour techniques,chemicalanalysis, Mossbauerspectroscopy,X-ray radiography,and petrologicalanalysis, the resultsall point to the use of two
typesof clay and two general manufacturingmethods,giving rise to amphoras of contrastingphysicalproperties.Theywereproducedat a single or
neighboringcenters. Thepetrologicalresultsare consistentwith an origin
along the Atlanticcoast close to the Straitsof Gibraltar,either in Morocco
Or tpaln.
Introduction
Excavationnearthe centerof the ancientcity of Corinth, Greece, in 1975 uncovered,amongotherthings, a
rectangularpit filled with discardedpottery, much of
which was coarse in fabricand in form generallyidentifiableas from containersfor wine and, less generally,
for goods thatneededto be shippeddry.1The remarkable
fact aboutthis pit is thatit containedtwo relativelycomplete examples of a type of amphorathat was known
previouslyonly by one example in Greece, that being
fromthe excavationsat Olympia.2The materialfromthe
Corinthianpit was dated by the glazed potteryit containedto ca. 460-440 B.C.
1. C. K. Williams, II, "Corinth, 1975: Forum Southwest," Hesperia
45 (1976) 104-107; for the amphoras, see catalogue nos. 27-30, and
the note at the bottom of p. 107.
2. W. Gauer, Olympische Forschungen VIII, Die Tongefasse aus den
Brunnen untermStadion Nordwall und im Sudost-Gebiet (Berlin 1975)
67, pl. 22, no. 3, Brunnen 63 SO, a, not long before the mid-5th
century B.C.
In the springof 1977 and 1978 a surprisinglyheavy
concentrationof clay transportamphorasof the 5th century B.C. was excavatedfrom within the confines of a
rectangularbuildingthatlies immediatelyeast of the pit
excavatedin 1975.3The greatestamountof sherdswas
found laid in layers in the centralcourtof the building
and within a porticoalong the northside of that court.
In amongthe smashedamphoraswere foundpocketsof
fish scales, in some cases still preservingthe form in
whichtheyhadbeen sliced. Examinationof the segments
of scales showedthatthe fish hadbeenfilleted,the strips
then shippeddry or in brine. Corinthwas one of the
3. C. K. Williams, II, "Corinth 1977, Forum Southeast," Hesperia
47 (1978) 15-20; idem. "Corinth, 1978: Forum Southwest,'' Hesparia 48 (1979) 107-124. For excavation of the north edge of the
Punic Amphora Building, which did not, however, produce strata of
discarded amphoras, see C. K. Williams, II, "Corinth Excavations,
1979," Hesperia 49 (1980) 108-111. For a detailed discussion of
Corinthian amphoras from this building, see Carolyn Koehler, "Corinthian Developments in the Study of Trade in the Fifth Century,"
Hesperia 50 (1981) 449-458.
et al.
206 Punic Amphorasat Corinth:Originand TechnologylManiatis
marketsfor those fish, andthe house in whichthey were
found appearsto be the place where the productwas
distributedor processed. A numberof questions arise
from the finding of the amphorasand fish within what
now is called the Punic AmphoraBuilding.
With whom was the proprietorof the PunicAmphora
Buildingtradingso extensively in the middle and third
quarterof the 5th centurys.c.? The questionis resolved
by a studyof the amphorasrecoveredfromthe debrisof
the building.About40Woof the amphoras,by weightof
sherdsrecovered,was Punic, 40SoChian,SSolocal Corinthian.VariousotherGreekcities suppliedthe last 15%
of amphoras,the best representedamongthembeing the
Mendeancontainer,or vanationsthereof.Amphorasfrom
the northernAegean are no surprisein this context, for
Corinthhad access to this area in the mid-Sthcentury
B.C. throughher colony, Poteidaia.The surprisingfact,
rather,is the large percentageof Punic materialwhich,
until the finding of the Punic AmphoraBuilding, was
almostunknownin Greece.
Whichtype of amphorawas used for the shippingof
the fish? Mende and Chios were known in antiquityfor
theirgood wines;the customarycontainerfor thosewines
arejars similarto those fromthe PunicAmphoraBuilding. Their long, slendernecks make them logical containersfor the shipmentof wine, much less so for the
packingof fish, even filleted. The study of the fish remains from the debris of the Punic AmphoraBuilding
suggests that the Black Sea cannotbe the supply area.
The bream,at least, must come fromthe Mediterranean
or from the warmwaterAtlantic.4Tunny, of which remains were found in the Punic AmphoraBuilding, is
still fished commerciallyin the westernMediterranean,
from Sicily to Spain, as well as in the Atlantic. Punic
are known to have
cities of the westernMediterranean
made a livelihood from the catchingand selling of fish
and relatedproducts,such as garum.It is thereforereasonableto assumethatthe fish were shippedin the Punic
amphoras,not in the Greekwinejars. Hole-mouthedjars
may also have servedfor the transportof the filletedfish;
the originof this type of containeris still unidentified.S
The hole-mouthedjar is representedby very few ex4. I thank Alwyne Wheeler of the British Museum (Natural History)
for the identification of the remains of the fish. For a preliminary
report, see Williams, 1979 op. cit. (in note 3) 117-118, especially
note 17, pl. 46.
5. C. K. Williams, II, "Corinth, 1978: Forum Southwest," Hesperas
48 (1979) 115-117, fig. 3, pl. 45. On p. 115, especially note 14, it
is implied that certain examples may be native to Motya, a Punic
settlement of western Sicily. Examination of the fragments of holemouthed jars by persons familiar, first hand, with the jars from Motya
indicates that the Corinthian jars are of a finer fabric and thus were
not made in the kilns of Motya.
ej
cz
Pigure 1. (a) Map of the
Mediterranean showing the
location of some of the
sites mentioned in the text.
(b) Punic amphora from
Corinth.
b
amplesin the PunicAmphoraBuilding,and, becauseof
its rarity here as comparedwith the widely scattered
remainsof fish, it is best to assume that, althoughthe
hole-mouthedjars may have been used to ship fish, they
arenot numerousenoughto havebeen the containersfor
all of the fish used in the PunicAmphoraBuilding.
Where were the Punic amphorasfound at Corinth
(F1GS. 1 a-b)? Numerous
exampleshavebeen
manufactured
reportedfromvariouswrecksalong the coast of Spain.6
These have been identifiedand groupedby form into a
special class of amphoras.7But becausethe finds come
mainlyfrom the sea, the find spot can only suggestthat
the locality of origin is in the westernMediterranean,
and not necessarilyon the IberianPeninsula.In fact, a
6. R. Pascual Guasch, "UnderwaterArchaeology in Andalusia," IJNA
2 (1973) 1 12-1 18.
7. R. P. Guasch, "Un nuevo tipo de anfora Punica," ArchEspArq
42 (1959) 12-19.
Journal of Field ArchaeologylVol. 11, 1984
numberof archaeologicalfacts suggestthatthe amphoras
were made in present-dayMorocco, perhapsalong the
Atlanticcoast at Kouassor withinthe neighborhoodof
Kouass.8
Above and beyondthe threequestionsalreadyasked,
a certainnumberof questionscan be posed concerning,
specifically,the Punic material.Even a casualobserver
can note the wide range of colors and texturesin this
class of amphora,as well as the varietyand density of
inclusionsused. In contrast,however, standsthe shape
of the container,which from the sample excavatedin
the Punic AmphoraBuildingshows almostno variation
or evolution in form. The variationin body shape is
muchless thanthat,for example,of the Chiancontainers
foundin the same building.
Why is therea greatrangein the fabricbut not in the
shape?Are the amphorasfired underspecificationsaccording to the productthat is to be shipped in those
containers?For example, is one color of clay meantto
signify that it containssea bream, while anothercolor
tunny?Or is the differencein clay the resultof firingin
orderto makecertaincontainersbetterfor the shipment
of fish in brineor in an oil solution,othersfor driedfish?
Can, on the other hand, the variationsindicatethe differencebetweenpotters'shops, kilns, or localities?
If the variationof color and fabric results from the
geographicaldistancebetweenthe centersof production,
how far apartwere those centers?If these questionscan
be answered, even in part, the results will contribute
markedlyto the study of patternsof tradebetweenthe
westernPhoeniciansandthe Corinthiansof the 5th century B.C.
The issues raised by the discovery of the amphoras
are clearlydiverse;they essentiallyconcerntwo aspects
of these amphoras,as ceramiccontainersand as objects
of trade, that are both well suited to investigationby
scientifictechniques.The opportunityhas been takenin
this work to employ a wide rangeof techniquesappropriateto the needs of the provenanceand technological
examinationsand to determinethe extent to which the
differentsets of resultscomplementor corroborateeach
other. Besides the establishedmethodsof analysis for
the determinationof chemical and petrologicalcomposition, the other techniques employed, Mossbauer
spectroscopy,scanningelectronmicroscopy,X-ray ra8. M. Ponsich, "Kouass, port antique et carrefour des voies de la
Tingitane," Bulletin d'archetologie marocaine 7 (1967) 369-405. See,
especially, p. 376, where mention is made of kilns dated from the 5th
century B.C. downward and of different techniques used in the different
kilns. See also the amphora illustrated in fig. 3, III. I would like to
thank Mrs. M. L. Zimmerman Munn, who visited the site, for her
opinion that the fabrics at Kouass, if not the same as the Punic amphora fabric found at Corinth, are very close in colors and inclusions
to those being discussed in this article.
207
diography, and porosity measurements,are relatively new
in ceramic studies.
Results
1. Hand-Specimen Examination
Thirty-one samples, representing the range of colors
and textures of the Punic amphoras found at Corinth,
were examined initially under a binocular microscope for
a rough classification of the sherds. The basic criteria
used in this analysis were essentially those that have been
described by Peacock,9 and for the most part they are
dependent upon the mineralogy of the very coarse to
medium sand grains (2.0-0.25 mm). On the basis of this
analysis two groups emerged, one with dark angular inclusions and the second with light colored, rounded minerals and rock fragments. The latter group was divided
into four subgroups on the basis of color. 10
Group I' (Samples 4, 6, 9, 10, 11, 1S, and 30)
Color: either reddish brown (SYR S/3) often grading into
reddish yellow (SYR 6.5/6) towards the outer surface,
or yellowish red (5YR S/6) becoming slightly stronger
(SYR S/8) towards the outer edge. Sample 10 was greyish brown (2.5Y S/2) with a mottled appearance.
Hardness:very hard;feel: harsh;fracture:hackly.
Inclusions:abundant;angular;moderately sorted, mostly
in the size range 1.0-O.S mm. The grains consisted of
colorless and light brown quartz; white quartzite and
limestone; dark green minerals; and sparse, dark grey
rock fragments.
Surfacetreatment:some of the samples were coated on
the exterior surface with a very pale brown slip (1OYR
813).
Group II'
Color: (a) pale yellow (SY 8/3) sometimes with a reddish yellow core (7.5YR 8/6): samples 7, 21,
22, and 23.
(b) predominantly light pinkish brown (7.5YR
7/4) but with some red (2.5YR S.S/8): samples 16, 17, 18, 19, and 20.
(c) red sometimes with a light pinkish brown
core1l: samples 1, 2, 3, 5, 12, 13, 14, 24, 25,
26, 27, 28, and 29.
9. D. P. S. Peacock, ed., Pottery and Early Commerce(London
1977) 29.
10. Munsell, Soil Color Charts(Maryland 1973).
11. Munsell notation as for (b).
a
E
208 Punic Amphorasat Corinth:Originand TechnologylManiatis
et al.
(d) light pinkish brown (7.5YR 7/4) with a large
grey core (2.5YR N5): samples 8 and 31.
Hardness:hard; feel: rough, often powdery; fracture:
hackly.
lnclusions:abundant;subangularto well rounded;sorting
moderate in the range 1.0-0.5 mm except 31 which was
0.5-0.25 mm. The grains consisted of colorless, grey,
and brown quartz;white quartzite and limestone; fossils;
and sparse white and golden mica.
SuCfacetreatment:several examples in subgroups (a) and
(b) had a slip. The surface color varied from very pale
brown (1OYR 7.5/4) to pale yellow (2.5Y 8/3).
2. ChemicalAnalysis
The chemical analyses were carried out by optical
emission spectroscopy using, essentially, the method described by Jones. 12 In view of the relative coarseness of
the amphoras, samples of at least 75 mg in weight were
prepared from fragments that were cleaned of slip and
weathered surface. 13 The nine elements selected for measurement were those normally determined (in their oxide
form) by the Fitch Laboratory and the Research Laboratory for Archaeology at Oxford in their provenance
studies of pottery. It should be understood that the compositions, which are set out in Table 1, are partial in the
sense that the major element, silicon, and such minor
elements as potassium, have not been determined.
Following a standardization procedure and transformation of the trace element (Mn, Cr, and Ni) contents
to log form, the 31 compositions were classified by two
techniques of multivariate analysis, cluster analysis
(Ward's method), and principal components analysis. 14
In the dendrogram of the former analysis, the two terminal clusters merged at a coefficient (of dissimilarity)
of only 17. 1; for convenience, they are superimposed on
the plot of the first two principal components (FIG. 2,
Clusters I and II); the Fe and A1 contents are the main
elements loading the first principal component, which
accounts for nearly half of the total variation in composition; the Na and Ni contents dominate the second
principal component (24%) and Ca the third (17%). As
an independent check on the validity of the classification
12. R. E. Jones, Greek and Cypriot pottery: a reloiew of scientific
studies (Athens, forthcoming) Chapter 2. This chapter also deals with
the performance characteristics of the analytical technique.
13. For discussion of this point see H. W. Catling, J. F. Cherry,
R. E. Jones, and J. T. Killen, "The Linear B Inscribed Stirrup Jars
and West Crete," BSA 75 (1980) 60-61.
14. These, together with the RELOCATION subprogram, are part of
the CLUSTAN IC package (Release 2) (D. Wishart, Edinburgh 1978).
achieved by cluster analysis, a relocation program15was
employed; only one sample (9) was reclassified.
An apparentlyanomalous result was obtained for 1 and
2. They were rim and lower body fragments taken from
the same amphora, and yet their compositions appear in
different clusters (FIG. 2). This potentially disturbing result seemed to be confirmed when freshly preparedsamples of the two fragments were analyzed and the same
discernible discrepancy in composition was again encountered (see TABLE 1). The problem was further explored by analyzing two new fragments from the same
amphora; that their compositions were comparable with
the earlier ones may suggest that the vessel was not made
of a homogeneous clay mix. These two new samples,
because they are similar to 1 and 2, are not considered
further in this paper.
Visual inspection of the individual compositions and
comparison of the mean compositions of the members
of the two clusters (TABLE 2) certainly bear out the point
that the overall variation in the composition of the amphoras is not marked; such a result may be expected in
material of common origin, the quality of whose fabric
is variable. The only element that does vary widely is
15. See note 14.
PC2
'
'
o
-
l
-2
3
4
-4
-2
0
2
4
PCA
Figure 2. Plot of the first two principal components, PC1 and PC2,
which account for 48% and 24% respectively of the variation in the
chemical compositions. The Fe and A1 contents dominate PC1, the
(- ) Na and Ni contents PC2. I and II represent the two terminal
clusters in the dendrogram of the cluster analysis. Sample 9 is
unplaced.
Journal of Field Archaeology/Vol. 11, 1984
209
Table 1. The chemical compositions (weight No)of the Punic amphoras.
Sample
1
1'
2
2'
3
4
5
6
7
8
CaO
19.4
18.8
19.7
18.1
15.1
10.2
17.5
9.4
18.7
16.0
9.4
11.5
9.3
19.5
15.2
16.6
10.0
11.0
14.0
18.3
13.6
11.2
20.4
16.2
16.2
17.2
16.0
19.7
9.7
20.1
14.4
9.6
13.6
Al203
15.5
15.7
17.1
17.5
16.1
19.9
17.3
21.0
20.5
18.5
22.2
20.0
14.9
16.0
15.8
15.8
25.0
17.0
16.4
13.0
16.1
14.9
19.2
21.3
17.7
18.1
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
1 1.9
18.2
25.0
14.6
15.4
19.2
18.5
MgO
1.5
1.8
2.9
2.8
1.9
1.9
1.8
2.3
3.0
2.4
1.2
2.2
1.8
1.8
2.1
1.7
3.5
1.8
2.1
1.4
1.6
1.5
2.4
2.5
2.0
2.1
1.3
2.2
2.9
1.8
1.7
2.7
2.1
Fe203
5.1
5.4
7.2
6.8
5.4
7.5
5.3
7.0
5.8
7.2
6.0
8.0
5.5
4.4
5.4
6.1
8.9
6.1
7.6
3.8
6.2
5.6
8.5
9.1
7.4
7.6
4.1
8.0
8.1
6.6
4.6
8.1
6.8
TiO2
0.58
0.60
0.70
0.68
0.70
0.72
0.63
0.78
0.73
0.80
0.74
0.72
0.65
0.61
0.68
0.70
0.99
0.71
0.74
0.56
0.86
0.63
0.84
0.84
0.78
0.80
0.69
0.85
0.84
0.74
0.63
0.72
0.75
Na20
0.43
0.53
0.79
0.84
0.50
0.83
0.46
0.73
0.53
0.75
0.61
0.89
0.50
0.38
0.82
1.05
1.35
0.57
1.02
0.30
1.75
0.52
2.05
2.27
1.82
1.38
0.28
1.22
0.90
1.50
0.82
0.98
0.99
Cr203
0.014
0.019
0.027
0.021
0.013
0.024
0.022
0.016
0.019
0.041
0.013
0.018
0.018
0.010
0.012
0.018
0.020
0.017
0.010
0.011
0.022
0.015
0.015
0.014
0.013
0.014
0.010
0.010
0.032
0.019
0.012
0.028
0.021
MnO
0.053
0.057
0.062
0.065
0.056
0.130
0.055
0.094
0.066
0.166
0.076
0.177
0.100
0.046
0.049
0.059
0.096
0.094
0.048
0.045
0.071
0.054
0.065
0.064
0.060
0.058
0.058
0.049
0.115
0.056
0.040
0.096
0.078
NiO
0.007
0.008
0.017
0.014
0.006
0.007
0.007
0.006
0.005
0.017
0.005
0.006
0.016
0.005
0.005
0.006
0.007
0.007
0.004
0.005
0.005
0.006
0.006
0.004
0.004
0.006
0.005
0.005
0.010
0.004
0.005
0.009
0.006
Samples 1' and 2' are the compositions derived from reanalysis of 1 and 2.
Table 2. The composition characteristics of Clusters I and II (the Punic amphoras) and a group of 22
samples of semicoarse wares from Corinth.
Al203
CaO
MgO
Fe203
TiO2
Na20
MnO
Cr203
NiO
Cluster I
(11 samples)
x
s.d.
19.7
3.1
11.8
3.3
2.4
0.5
7.3
1.0
0.76
0.09
0.84
0.23
0.110
0.035
0.024
0.008
0.010
0.005
Cluster 11
(19 samples)
x
s.d.
16.5
2.3
16.8
2.5
1.9
0.4
6.1
1.5
0.72
0.09
1.01
0.63
0.055
0.008
0.014
0.004
0.005
0.001
Corinth
Semicoarse pottery
group (22 samples)
x
s.d.
18.5
3.3
14.7
2.7
3.3
0.6
9.5
1.0
0.74
0.09
0.89
0.48
0.098
0.016
0.037
0.007
0.037
0.011
x = mean percentage
s .d. = standard
.
.
devlatlon
210 Punic Amphorasat Corinth:Originand TechnologylManiatis
et al.
Mn, but this element does not apparently correlate with
any other, nor does it feature strongly in the principal
components analysis. The significance of the two clusters may, therefore, appear tentative, but as we shall
demonstrate below there is strong independent support
for their validity from Mossbauer spectroscopy and the
petrological data. The differentiation between the two
clusters is attributedmainly to the variations in two elements, Fe and A1. The role of these elements in the clay
is wholly or partly structural, and as such they are generally less informative about origin than are many of the
minor and trace elements. The importantconsequence of
this observation, admittedlybased on the experience with
Greek clays, is that the clusters are more likely to represent related clays, perhaps tempered differently, from
the same geographical region than those from distinctly
separate localities. In this connection it is noted that the
resemblance in the mean compositions of the two groups
extends to two of the measured elements that are originsensitive, Cr and Ni. Having established that the compositions are consistent with the amphoras being manufactured at a single or neighboring centers, it is not,
unfortunately, possible to progress to the stage of trying
to locate their origin; this circumstance is entirely because of the absence of relevant reference data from possible sites in the Mediterranean. As a heuristic exercise,
however, it can be confirmed, at least, that they were
not made at Corinth; the Cr and Ni contents, in particular, in a group of 5th century B.C. semicoarse-ware pottery from Corinth are significantly higher than in the
amphorae(TABLE 2). Bouchard's analyses of pottew from
Mogador and of Punic amphoras found at Carthage are,
regrettably, too incomplete for any valuable comparison
to be made.l6
temperature and atmosphere. Since almost every clay
contains 5-10% iron, Mossbauer spectra can be readily
obtained with ca. 100 mg samples.
Iron present in clays appears (a) in the form of paramagnetic ions (ferric Fe3+ or ferrous Fe2+) substituting
Al or (less frequently) Si sites in the clay minerals and
(b) in the form of magnetic iron oxides or hydroxides
usually dispersed as small particles with sizes of the order of 100-20000 A. The paramagnetic ions produce a
doublet in the central part of the spectrum. Two "quadrupole doublets" assigned to paramagneticFe3+ and Fe2+
ions are indicated by the stick diagrams in the central
part of the spectrum shown in Figure 3 (components I
and II). Each doublet is characterizedby the velocity of
the center of gravity known as isomer shift and the separation of the two lines known as quadrupole splitting;
the quadrupole splitting of Fe2+ in clays is always larger
than that of Fe3+. A six-line pattern (component III) is
observed in magnetically ordered materials (i.e., magnetic iron oxides and hyroxides in clays), and their spectral features (i.e., line positions) depend on the particular
oxide, its particle size, and temperatureof measurement.
The six-line pattern usually collapses to a doublet for
small particles (ca. 100 A) and high temperatures (ca.
100°K). This phenomenon is called superparamagnetism
and it can be used for the determination of the particlesize distribution of the iron oxides or hydroxides.18 A
18. N. H. Gangas, A. Simopoulos, A. Kostikas, N. Yassoglou, and
S. Filippakis, ''Mossbauer Studies of Small Particles of Iron Oxides
in Soil," Clays and ClayMinerals21 (1973) 151-160.
l
3. Mossbauer Spectroscopy
I
Unlike other techniques of chemical analysis that have
been applied to clays and ceramics, the results of Mossbauer spectroscopy pertain only to one element, iron.
The unique feature of Mossbauer spectroscopy, however, is the detailed picture that it can provide about the
physical and chemical state of iron in the clay.l7 This
state depends on the original clay as well as the firing
n
loo
vo
l
I I
I
x8Ze
,
^
't
*^%
_
99.0
98
16. A. Bouchard, ''Correlations entre la composition chimique et la
provenance des poteries antiques," unpublished Ph.D. dissertation,
University of Clermont-Ferrand(1971). The mean Cr and Ni contents
of her Mogador and Carthage samples are 0.028% and 0.020% (Cr
oxide) and 0.006% and 0.005% (Ni oxide) respectively. These values
are not greatly different from those in Clusters I and II (TABLE 2).
17. A. Kostikas, A. Simopoulos, and N. H. Gangas, '4Analysis of
Archaeological Artifacts," in R. L. Cohen, ed., Applications of Mossbauer Spectroscopy (London 1976) 241-261.
Po
§
- 10
§
*
l
-E
-6
*
i
--
l
-Z
*
l
q
l
l
O
Z
4
6
8
+
10
UEL3CI TY ( MM/SEC)
Figure 3. A Mossbauer spectrum. Component I is the quadrupole
doublet of Fe3+, component II the quadrupole doublet of Fe2+, and
component III results from the magnetic iron oxides and hydroxides
in clays.
Journal of Field ArchaeologylVol. 11, 1984
useful parameterin the case of measurementsat room
temperatureis the magnetic ratio, which is defined as
the ratioof the magnetic(six-line)componentto the total
absorptionarea,andit gives the percentageof ironpresent as bulk oxides or hydroxides.The variationof the
spectralparameters,which are extractedfromspectraof
potterysamplesas describedabove, is the basis of the
applicationsof Mossbauerspectroscopyto ancient ceramics. Thus, for example, the quadrupolesplittingof
the ferricdoubletdependson the firingtemperature,althoughthe elementalcompositionof the clay itself introducescomplications.19Whatis more, the ratioof the
intensitiesof ferrousand ferricdoubletsis indicativeof
the prevailingatmosphereduringfiring. Similarly,the
physicalandchemicalstatesof the ironoxide phasesand
theirinteractionswith the otherconstituentsof the clay
correlatewith the color and textureof the pottery20and
can be associatedwith majorparametersof the manufacturingprocedure.
We carriedout Mossbauermeasurements,usinga constantacceleratorspectrometer,on the amphorasat room
temperaturein the "as received" (ASR) state and also
afterrefiringat 1080°C.The refiringat a high temperis assumedto level
atureandundercontrolledatmosphere
off all the factorsdependenton initial temperatureand
atmosphereand reveal the real propertiesof the clay.
Thatis, assumingthe amphoraswere madeof the same
clay, constantfiringconditionsshoulddevelopthe same
minerals and microstructureand, therefore,the same
Mossbauerparameters.Figure 4 shows some typical
spectraof samplesin the ASR stateand afterrefiringat
1080°C. It can be seen that the variationin the ASR
spectra is fairly random, but after refiring the correspondingspectratend to fall into two categories, one
displayinglargeparticlesof iron oxide, as witnessedby
the high magneticratio, and the other showing small
ones.2l Note thatthe samplesdevelopingthe largeoxide
particlesafterrefiringcontainan amountof ferrousiron
in the ASR state, indicatinga degreeof reductionin the
initial firing cycle. Figure 5 shows that the amphoras
separateinto two groupsaccordingto the values of two
Mossbauerparametersin the refiredsamples:the quad19. Y. Maniatis, A. Simopoulos, and A. Kostikas, "Mossbauer Study
of the Effect of Calcium Content on the Iron Oxide Transformations
in Fired Clays, " Journal of the American Ceramic Society 64 (1981)
263-269.
20. R. Bouchez, J. M. D. Coey, R. Coussement, K. P. Schmidt, M.
von Rossum, J. Aprehamian, and J. Deshayes, "Mossbauer Study of
Firing Conditions used in the Manufacture of the Grey and Red Ware
of Tureng Tepe," Journal de Physique 35 (1979) C6:541-547; A.
Chevalier, J. M. D. Coey, and R. Bouchez, ''A Study of Iron in
Fired Clay: Mossbauer Effects and Magnetic Measurements," Journal
de Physique 37 (1976) C6: 861-865.
211
rupolesplittingfactorof the mainferricdoubletand the
magneticratio. The latterresults,in particular,separate
the amphorasinto two clearlydistinguishedgroupswith
a possible intermediategroupof four samples.This result accordswell with the classificationof the chemical
compositiondata (FIG. 6).
The resultsof the refiringexperimentsshow that the
fromat least two different
amphoraswere manufactured
kinds of clays with differentrefractoryproperties.This
conclusionis consistentwiththe resultsof principalcomponentsanalysisof the compositiondata (FIG. 2) which
differentiatedthe groupsaccordingmainlyto the structuralelements, Al and Fe. It had been found in earlier
investigationsthat clays containingmore than 5% Ca
when fired in an oxidizing atmosphereusuallydevelop
very small iron-oxideparticlesabove 800°C, probably
as a resultof the reactionduringfiringof ironoxide with
calciumoxide and the clay mineralsleadingto the forThis process
mation of new Ca-Fe-alumino-silicates.22
resultsin the breakingdown of the size and quantityof
the iron-oxideparticles.On the otherhand, non-calcareous clays (less than 5% Ca) develop large iron-oxide
particles, presumablybecause the iron is less free to
move about duringthe destructionof the clay mineral
lattice with firing and in the presenceof oxygen in the
environmentwhich allows the formationof large oxide
particles.
In the case of the amphoras,therefore,one can say
that the groups, which upon refiringat 1080°Cexhibit
large and small magneticratios, behave as non-calcareous and calcareousclays respectively. The situation,
however, is more complicatedbecause all of the amphoraswere found to containmore than 9% Ca oxide
(TABLE 1); this problemis discussedlater(see note 41).
4. X-rayRadiography
X-raying
This techniqueinvolves the straightforward
of the sherds;it was appliedin this study to obtaininof inclusionsandpores
formationaboutthe concentration
inside the clay body as well as constructionaland orientationaldetails.23
of the amphorasshowed that they
The radiography24
were well built since few cracks or large pores were
detailswereevident.Pores
revealed;no furtherstructural
and inclusionsin some cases showed strongalignment
parallelto the surface.The most strikingfeatureis the
21. Maniatis et al., op. cit. (in note 19) 265-266.
22. Ibid. 267.
23. O. S. Rye, "Pottery ManufacturingTechniques: X-ray Studies,"
Archaeometry 19 (1977) 205-211.
24. Using a portable SCANRAY X-ray unit with a focal spot of 1.5
cm x 1.5 cm.
,
23
18
21
-
1
3;
|
-
sst
=
-
:,
.H
*
#*
:
^10
*127
*w
I
o
h
*
*
\
15.
.
.*
sWN
|
*
s
9'
*.
v
212 Punic Amphorasat Corinth:Originand TechnologylManiatis
et al.
Figure 4. Mossbauer spectra taken at
room temperature of 1, 2, 3 4, 6, and 9
in the i'as received state" (ASR) and
after refiring at 1080°C.
REFIRED:10{30 C
|
§
§00.9 .
§
$
-
ASR
|
|
-
|
|
¢
*
*
*
#
I
#
t
+
I
I
t
§
t
-
,
zrw
s,
**,--ww
s
t-
*:
f0^X-
tr-s
-
s
.
-
's
t
*t
*
**
v
;
f
w
.
*
.
*
.
.
4
4
. !*
F*.O
.
.
*s
Xo
9-.SS0ls
r
*
*s
|:
*
*#
S
*
t.o
9
*
^
4N.t.;
9
*
*
t
w
>
..^..^^r
*
i
ndo-
s
*;-
sX
*
*
*
\
:s
*
-
*
*
.*
*
w
.
4t
t
s
w
% , Ctt,2,,,
s
-
*
"
*
*
4
.o
l#f
:
*
_\, waK
-Z/rJ!
* *
;
**
.
ts'Us
*
-o
*
*
i
^
S:
en
U1
.
'.
6
6
-
r
".o
-
*
a o-
b7>¢---oW
lY
* *
.
*W
r^ww{t
s
-
s
s
*
_
J
S
t.0
.
100.0
n.o
.
o
>>--
".0
92.0
3
4
*
*
t
.
'
',
>
3
%.0
00.0
^
0*<
;w
**My.W*
*#
'
*i+a.
:.e.*
s
H-
'
.
#
*
t/-;'
,
.
*
*-
:
2
*^.0
-.-
2
:-*.
*.
§
-O
§
-
*
+
+
*
2
X
0
,
0
-s
t
-2
0
Z
t
4
4
0
UELBCI TY ( MS9C
Figure 5. Upper: the magnetic ratio
(AmlAT)values in the refired samples.
Lower: the quadrupole splitting (e2qQ/2)
values of the main felTic doublet in the
refired samples.
*
§
- 10
-8
)
t
-6
0
*
-4t
-2
I
0
UEL3CI l
,
,,"
12 26
205132921
0
,
ss
u
.
|
t
t
6
@
I
10
1
,
25 28
§
( MMs
SEC )
Y
11
o'
t
Z
22
X
\
,'
i"'ss
10
11
,/
"
F
S
,,''
M
30
20
40
6
13018
>
4
91
"'ss
50
60
ArnlAT (IQ80 *C}
n
28
18
o
,
s
>
'
27
,
"
_
_
,
6
Q70
4
9
X
0.80
10
\
17
21
19
31
25
12
16 1
27
23
14
24
5
I
_
7
20
13
3
_
11
'
29
o
_/
1
_
a
_
;
|
l 1
_
26
s
\
"
s
>
2
,
8
0.90
e qa
(1080
C J
S
-
-
Journal of Field ArchaeologylVol. 11, 1984
variationin the concentrationof dense inclusions (FIG.
7), the highest concentrationof them appearingin the
amphorasbelongingto ClusterI, which correspondsto
the groupwith the high magneticratio. This result fur-
PC2
3
2
213
ther consolidates the difference between Clusters I and
II in terms of technology of manufacture. There are only
two exceptions in this classification: 22 and 27 fall in the
wrong cluster as far as the concentration of inclusions is
concerned. The inclusions in the Cluster I samples, rather
irregular in shape and relatively large, were probably
added as filler or grit for reasons that are discussed later
(see section 6 and Discussion). They appear in the Xray film (FIG. 7) with considerably higher intensity than
the background, which indicates that they were made of
elements of higher atomic number than those of the clay
matrix, itself consisting mainly of Al and Si with atomic
numbers 13 and 14. It seems likely, therefore, that these
inclusions are made of elements at least twice as heavy.
5. Petrological Analysis
o
-2
--1
-3 -
-4
-2
- 4
0
2
4
PC1
O.
Low
,:
Med iun Am/AT
2:
High
Having established that two general groups of amphoras could be distinguished by slightly different chemical compositions and by different manufacturing
techniques, we selectively used petrological analysis in
an attempt to characterize the amphoras more fully.
Briefly, it may be recalled that the identification of the
mineral inclusions in petrological analysis defines the
geology of the raw materials that were used to produce
the amphoras;25it will become readily apparent that the
Am/AT
Am /Ar
Figure6. Comparisonof the chemicalcompositionsand Mossbauer
(magneticratio)results. o, lv and :1: low, medium,and high
magneticratiosrespectively(see FIG. S [upper}).
25. D. P. S. Peacock, "Roman Amphorae: Typology, fabric and
origins," in Me'thodesclassiqueset me'thodes
formelles dans l'e'tude
des amphores.Actes du Colloquede Rome, 1974 (Ecole Frangaise de
Rome 1977) 261-267.
Figure 7. X-ray radiograph of 1, 2, 3, 4,
5, 6, and 8.
214 Punic Amphorasat Corinth:Originand Technology/Maniatis
et al.
Punic amphoras are highly suitable material for this type
of analysis. In turn, geographical regions that are compatible with the petrological data can then be suggested.
The accurate and successful localization of sources,
however, is dependent on several factors, which include
the presence of distinctive mineral inclusions, the availability of detailed geological reconnaissance in the regions of interest, and reference materialfrom the possible
sources.
Twenty-two samples were selected for thin sectioning,
and their examination was carried out using a Swift MP
120 polarizing microscope. This was supplemented with
point counting and measuring to give relative proportions
of the constituents and their size. Again two groups were
separated, and they are termed Groups I and II,26 the
latter being subdivided into five smaller assemblages, (a)
to (e).
The results of the grain-size analysis are discussed first
as they concern the amphorafabrics as a whole. Thirteen
samples (at least two from each subgroup) were examined, 300 grains being counted in each sample. The general shape of the graph (FIG. 8) was the same in all cases
except for 18. At the coarser end the cut-off points differ;
Group I tends to be greater than 1 mm, whereas Group
II is no greater than 1 mm and often does not reach this
level. The sharp drop in the gradient in the fine-sand
region reflects the small quantity of grains of this size
in the samples. The steeper gradient at the coarse end
indicates the addition of temper, and at the fine end the
presence of abundant very fine sand and silt in the clay
matrix. Sample 18 is not so well sorted, having overall
a more consistent gradient owing to the greater quantity
of fine sand present, and the relatively large grain sizes
at the finer end of the scale than in the other samples.
Group I (Metamorphic): Samples 4, 6, 10, and 15 (PLATE la)
In thin section this fabric was characterizedby its color
in crossed polarized light. This was predominantly dark
red, but with dark green haloes surrounding the voids.
Other highly distinctive features of this group were best
observed in plane polarized light at low magnification.
By these means colorless garnet and strongly pleochroic
chlorite and amphibole(?) were observed. The samples
in this group contained significant quantities of quartz
(mono- and polycrystalline), kyanite (a few examples
bearing inclusions of sillimanite) and chloritoid(?) with
subordinate orthoclase feldspar. Many of the minerals
26. The classification of the petrological groups, I and II, follows the
same nomenclature as those of the chemical analysis, Mossbauer spectroscopy, and X-ray radiography results. A distinction is deliberately
made in the case of the hand-specimen groups which are designated
I' and II'.
lll
:
I
__
_
_
_
_
_
.eg11111
1
1
1
1
1
2
1
0.5
025
0.125
0.0625
0.031
0 0150 mm
V.COARSECOARSE MEDIUM FINE
V.FINE COARSEMEDIUM
SAND
SAND
SAND
SAND
SAND
SILT
SILT
Figure8. Grain-sizeanalysis.
were also represented in rock fragments, of which mica
schist was the most abundantrock type. The matrix contained a great many very fine grains which were mostly
of quartz, biotite and white mica, plagioclase, and some
red iron oxide (probably haematite) together with scatters
of lime. The majority of the inclusions were angular to
subrounded.
Attention is drawn to 10 which is of particularinterest
because of the occurrence, in several instances, of dark
brown to black opaque material which surroundeda center composed of numerous voids and a pale green (nonpleochroic) cryptocrystalline material. This material presented in places second to third order interference colors
and contained considerablequantitiesof very small, black
opaque inclusions; these are thought to be an alteration
product.27
GroupII (Sedimentary)(PLATElb)
(a) Sand with lime scattered through the matrix (7 and
21).
(b) Sand with some limestone (17, 18, 19, and 20).
(c) Sand with limestone and fossils (1, 2, 3, 5, 13, 14,
and 26).
(d) Sand, limestone and fossils, but with some rounded
metamorphic grains (8 and 31).
(e) Rounded low grade metamorphicrock fragments (11,
16, and 22).
These subgroups are characterized as follows.
(a) This group consisted of subangular to well rounded
grains of mono- and polycrystalline quartz, orthoclase feldspar and sparse plagioclase (with albite
twinning). The orthoclase was often cloudy and occasionally the presence of alteration to sericite was
27. I. K. W. thanks Dr. I. C. Freestone of the British Museum Research Laboratory for his discussion of this sample.
Plate l(a). Fabric 1 (low-grade metamorphic): sample 6 (width of photograph 7.3 mm). Seen in cross polarized light:
white quartz, polycrystalline quartz and kyanite; yellow chlorite and amphibole(?); colorless garnet next to
amphibole(?) in top right hand corner.
Plate l(b). Fabric 2b (sedimentary sand, limestone, and fossils): sample 2 (width of photograph 7.5 mm). Seen in
crossed polarized light: white quartz and plagioclase; microfossils just below center, to left and right.
Journal of Field ArchaeologylVol. 11, 1984
noted. A few of the orthoclase grains also displayed
microperthiticintergrowths. Many of the grains were
covered by a thin band of lime around their circumference. The matrix was dark green in crossed polarized light, contained fine-grained quartz, and
abundant lime scattered in patches. Although some
small grains of red iron oxide occurred, the apparent
absence of fine mica in the matrix contributed to the
distinct nature of the fabric of 7.
The refiring of 3 and 5, which were placed in
subgroup (c), to a temperatureof 1080°C resulted in
a fabric very similar to (a). In fact, the main difference was the absence of scattered lime in the refired
samples. It is therefore proposed that (a) is a technological subgroup derived from (b) or (c) as a result
of the decomposition of limestone and fossiIs between 675 and 950°C,28ratherthan a source subgroup
based on the availability of different minerals.
(b) This subgroup contained the same range of inclusions as (a). Many of the grains were well rounded
and of high apparent sphericity (as judged only in
the two dimensions of thin section). In cross polarized light the color of the matrix was yellow brown.
The presence of well rounded grains of limestone
and abundant lime scattered throughout the matrix
characterized the fabric of (b). Again, grains occurred that had received a thin coating of lime as
describedin (a). The matrix also containedfine grains
of biotite and white mica, possibly accompanied by
phlogopite, together with red iron oxide and rutile.
(c) A close relationship with (b) was readily apparent,
the most noticeable difference being the presence of
microfossils (in this case Foraminifera). These samples also contained well rounded grains of limestone
that clearly displayed a polycrystallinestructure,with
individual subgrains having different optical orientations. The source must, therefore, have been a
crystalline limestone or marble; otherwise, the color
and mineral content of the fabric were the same in
thin section as for (b).
(d) In cross polarized light the two samples in this
subgroup differed in color and in grain size;29 one
had a dark brown matrix while the other was dark
green. The majority of the grains were subrounded.
They consisted of mono- and polycrystalline quartz
together with orthoclase and plagioclase feldspars.
The latter were of varied degrees of alteration and
28. D. N. Todor, Thermal Analysis of Minerals (Abacus Press: Kent
1976) 161.
29. Sample 31 was much finer grained than any of the other Punic
amphoras both in hand specimen and in thin section.
215
cloudiness. In some cases the orthoclase was microperthitic. Limestone and microfossils, accompanied
by bivalve shell fragments, were common. In addition, a few fragments of sandstone were noted (very
fine subrounded sand in a fine silty matrix). The
metamorphic minerals and rock fragments included
sparse garnet, chlorite and pyroxene (augite), green
and brown serpentinite, white mica schist, and phyllite. The matrix contained silt grains of quartz and
feldspar with sparse rutile, zircon, biotite, and, possibly, phlogopite micas.
(e) Like (d) the colors of the matrix in crossed polarized
light differed within the subgroup;two samples were
dark brown and one dark green. There was also similarity in the mineralogy between the two subgroups,
especially the presence of sandstonefragments. There
were, nevertheless, differences between them, the
main one being the near absence of microfossils and
limestone grains. This was accompanied by an increase in the quantity of phyllitic rock fragments,
which also frequently displayed microfolds. Biotite
and muscovite schists, together with garnet and
chlorite, resembled the rock fragments of Group I,
particularly in the case of 11 which also contained
grains of augite. Serpentinite was present, containing
garnet, as was a chlorite-plagioclase (with Carlsbad
twinning) schist. A single rock fragment of white
mica, quartz, and kyanite was recorded, as was the
occurrence of two well rounded grains of cordierite
and very sparse chloritoid(?).
A summary of the most important minerals and rock
fragmentsis presentedin Table 3. The proportionsquoted
are purely qualitative because of inaccuracies in point
counting and measuring as well as the number and size
of samples available. Nevertheless, the percentages of
matrix to mineral and rock inclusions (greater than about
0. 125 mm) were obtained by point counting and are considered to reflect accurately these proportions.
The presence of sedimentary rock fragments such as
limestone, fossils, and sandstone along with rounded
metamorphic grains in the same samples of subgroups
II d and II e, which in some cases (notably 11) were
similar to the fragments in Group I, suggest that the
fabrics were all produced within the same general region.
The fresh and angular grains in Group I would tend to
indicate that the metamorphic source was not too far
from the site of production. Too little is understood,
however, about the collection and processing of the raw
materials for ancient pottery production to ignore the
possibility that the material may have been transported
by the potters quite some distance from its site of formation, or indeed its site of deposition by natural agencies.
216
Punic Amphoras at Corinth: Origin and Technology/Maniatis et al.
Table 3. The frequency of the principal minerals and rock fragments in Groups I and II.
Minerall
rock fragment
II
I
a
b
c
e
d
Quartz Monocrystalline
Abundant
Abundant
Abundant
Abundant
Abundant
Abundant
Quartz Polycrystalline
Common
Sparse
Sparse
Sparse
Common
Common
Sparse
Sparse
Sparse
Sparse
Sparse
Common
Common
Common
Common
Sparse
Sparse
Sparse
Common
Sparse
Chert
Orthoclase Feldspar
Sparse
Plagioclase Feldspar
Sparse
Kyanite
Sparse
Sillimanite
Sparse
Chloritoid(?)
Common
Sparse
V. Sparse
V. Sparse
V. Sparse
Cordierite
Garnet
Common
Sparse
Sparse
Chlorite
Abundant
Sparse
Sparse
Amphibole(?)
Common
Sparse
Sparse
Pyroxene
Common
Sparse
Schist
Common
Common
Common
Phyllite
Sparse
Sparse
Common
Sparse
Common
Abundant
Common
Sparse
Common
Common
Sparse
Sandstone
Serpentinite
Abundant
Limestone
Fossils
Clay Pellets
Sparse
Common
Common
Common
Sparse
Sparse
Matrix
80-90Wo
70Wo
70Wo
70Wo
70%
70%
Althoughthe metamorphicrockfragmentsare distinctive with respectto isolatingdifferentfabrics,the inclusions cannotbe used with a high degree of confidence
for provenancepurposes,as most of the rock types representedare extremelycommon. The region in which
the Punicamphorasarethought(on presentevidence)to
have originatedis eitherside of the Straitsof Gibraltar,
in southernSpain, or northernMorocco. As mentioned
in the Introduction,there is alreadyarchaeologicalevidence for productionof such amphorason the Atlantic
coast of Moroccoat Kouass.30
The geological situationin this region is highly unsuitable for choosing between northernMorocco and
southernSpain, in that the formationsof the Moroccan
Rif appearto takea "U'' shapedbendto the west of the
Straitsof Gibraltarand returnto form the Betic region
of southernSpain;hence the same rangeof rock types
30. Ponsich, op. cit. (in note 8).
appears on both sides of the Straits.3l All of the petrologically defined fabrics could have originated on either
side of the Straits, although (judging purely from the
literature)the Atlantic coast would appear more likely to
provide the sedimentar fabrics than the metamorphic.32
The fabrics described by Peacock33 for Roman amphoras from production sites in southern Spain do bear
an overall similarity to some of the sedimentary Punic
31. J. M. Rios, "The MediterraneanCoast of Spain and the Alboran
Sea," in A. E. M. Nairn, W. H. Kanes, and F. G. Stehli, eds., The
Ocean Basins and Margins: 4B The Western Mediterranean (Plenum
Press: New York and London 1978) 1-65 and fig. 14.
32. H. E. Rondeel and 0. J. Simon, "Betic Cordilleras," in A. P.
Spencer, ed., Mesozoic-Cenozoic Orogenic Belts, The Geological Society: Special Publication 4 (London 1974) 23-35; G. Choubert and
A. Faure-Muret, "Moroccan Rif," in Spencer, ed., op. cit. (this note)
37-46.
33. D. P. S. Peacock, "Amphorae and the Beitican Fish Industry,"
AntJ 54 (1974) 232-243.
Journal of Field ArchaeologylVol. 11, 1984
amphora fabrics, but the near absence of metamorphic
material does not encourage correlation.34 Analysis of
Punic amphorasfrom production sites, together with surveys in search of other such sites on the Atlantic and
Mediterraneancoasts, will be necessary before the origin
of the various Punic amphorafabrics can be established.
Combiningthe results of petrologicalanalysis and handspecimen examination we propose the following fabrics.
Fabric1 GroupI (Metamorphic)
Fabric 2a SubgroupII a (Sedimentarybut reflecting a
technologicaldivision)
Fabric2b SubgroupsII b and c (Sedimentarywith and
withoutfossils)
Fabric 2c SubgroupsII d and e (Sedimentary-metamorphic with and without
fossils and limestone)
The classificationsderivedfrom chemicaland petrological analysescan now be compared,bearingin mind
thatthereis an imbalancein the numberof samplesanalyzed in each case. The main commentto make is that
the correlationbetweenthe two classificationsis good.
FabricI (metamorphic)correlateswith ClusterI, while
the sampleswith inclusionsof sedimentaryorigin, Fabrics 2a and 2b, fall uniformlyinto ClusterII. The distinctionbetweenFabrics2a and2b (sedimentary),on the
on
one hand,andFabric2c (sedimentary-metamorphic),
the other,is bornest, if imperfectly,in termsof chemical composition.Samples8, 11, 16, and 31 are found
within the metamorphicgroupof ClusterI, but 22 belongs securelyto ClusterII; the compositionof 8 is unusual for its relativelyhigh contentsof all three trace
elements. Furthermore,1 and 2, which came from the
sameamphorabutgave anomalouschemicalresults(section 2), were foundto be petrologicallysimilar,both of
them of sedimentaryorigin (Fabric2b).
A discussionof the minerals,rock fragments,andthe
sourcesof the temperis given in the Appendix.
6. Porosity Measurements
There are two types of pores in a ceramic, the open
pores, effectively capillarytubes extendingto the surface, and the closed pores, which do not extend to the
surface.35It is evidentthatthe open poresdirectlyaffect
propertiessuch as permeability,a highly relevantfactor
34. This also applies to the Punic amphoras from Uzita; see J. H.
van der Werff, "Amphores de tradition punique a Uzita," BABesch
52-53 (1977-78) 171-200. I. K. W. thanks Dr. D. P. S. Peacock
for this reference and discussion.
35. W. D. Kingery, H. K. Bowen, and D. R. Uhlman, Introduction
to Ceramics (New York 1976) 518-521.
217
in the case of food-storagevessels such as the Punic
amphoras.
The open or apparentporosityis definedas the ratio
of the volume of the open pores to the total volume of
the pieces, and in order to measureit samples of approximatedimensions, 3 cm x 3 cm, were boiled in
waterfor aboutfour hoursand left to cool overnightso
that all pores were filled with water. These saturated
specimenswere first weighed suspendedin water (Wb)
andthensuspendedin air(Wc).Finally,they wereplaced
in a dryingoven for severalhoursat 140°Candthe completelydriedspecimenswere reweighedin air (Wa).The
open porosity was calculatedfrom this data using the
following equation.
WC -
apparent poroSlty = W -
W
Wb
The results for the Punic amphoras are shown in Table
4; the range of porosity values is 24 to 40%, those near
the lower limit are produced either by fine non-calcareous clays at temperatureslower than 900°C or by coarser
calcareous clays (which is more likely to be the case
with the Punic amphoras) fired above 1050°C.36 The
higher porosities are exhibited by coarse calcareous or
non-calcareous clays at temperatures below 1000°C.
As far as the differences between the main clusters are
concerned, the Cluster I samples, developing large ironoxide particles and containing a high density of inclusions, have porosity values concentrating between 27%
and 31%, while the Cluster II samples attain porosities
which are much more wide-ranging. Bearing in mind
that tempering usually increases the porosity, it is evident
that the clays of Cluster I would have had ver low
porosities if they had not been tempered.
7. Scanning Electron Microscopy (SEM)
The examination of fresh-fracturedsurfaces of ceramic
samples under the SEM provides information of the internal morphology of the clay and the degree of vitrification that develops during firing.37 An estimate of the
original firing temperature can be made by combining
this information either with the data from clays and pot-
36. M. S. Tite and Y. Maniatis, "Scanning Electron Microscopy of
Fired Calcareous Clays," Transactions and Journal of the British
Ceramic Society 74 (1975) 19-22.
37. Y. Maniatis and M. S. Tite, "Ceramic Technology in the Aegean
World during the Bronze Age," Proc. 2nd Internat. Scient. Congress
on Thera and the Aegean World I (London 1978) 483-492; Y. Maniatis and M. S. Tite, "Technological Examination of Neolithic-Bronze
Age Pottery from Central and South-east Europe and from the Near
East," JAS 8 (1981) 59-76.
218 Punic Amphorasat Corinth:Originand Technology/Maniatis
et al.
Table 4. Technological results; vitrification stage and firing temperatureestimated from scanning electron
microscopy and porosity values.
Sample
Body color
WoCaO
Vitrif. Stage*
Firing Temp. (°C)
Open porosity (Wo)
Group I
4
6
9
10
11
Red-Grey
Grey-Brown
Grey-Brown
Dark green
Grey-Brown
10.2
9.4
9.4
11.5
9.3
V
V
TV
V
850-950**
850- 1050
850- 1050
1100
850-1050
27
27
27
31
27
Group 11
(a)
7
21
Green-Yellow
Green-Yellow
18.7
20.4
TV
V
1150
850-1050
31
38
(b)
19
Light brown
13.6
V
850-1050
33
(c)
1
2
3
S
12
13
14
Red-Brown
Red
Light brown
Red
Red
Red
Red-Brown
19.4
19.7
15.1
17.5
19.5
15.2
16.6
IV/V
IV
IV/V
IV/V
V-
800-850
750-800
850-950**
800**
800-850
800-850
800-900
33
26
33
31
30
30
31
8
31
Grey-Brown
Grey-Brown
16.0
13.6
IV
V
750-800
850-1050
30
29
800-900
850- 1050
34
34
(d)
(e)
16
Light brown
11.0
V22
Green-Yellow
16.2
V
*IV = Initial vitrification, V = characteristic cellular,
TV=total vitrification, IV/V, V-, TV-= Intermediate stages.
**Firing temperatures determined from Mossbauer spectroscopy results.
tery of known morphologies or by refiring the samples
and reexamining them under the SEM. In addition, the
degree of vitrification present in the microstructureof a
fired clay body can give an indication of its strength,
hardness, and porosity.
Seventeen samples were examined under the SEM in
the "as received" (ASR) form and afterrefiringat 1080°C
so that a direct comparison could be made with the Mossbauer results. The ASR samples showed a wide range
of microstructures because of variable firing temperatures and differing behavior of the clays during firing.
All the well fired samples exhibited a cellular type microstructurecharacteristicof calcareous clays fired in the
temperaturerange 850-1050°C.38 Two forms of microstructure, however, were discernible: more open (FIG. 9a)
and less open (FIG. 9b), and their apparentporosities were
found to be 34% and 27% respectively. Several samples
exhibited microstructuretypes of the initial vitrification
stage, while others had reached the total vitrification
38. Maniatis and Tite, 1981 op. cit. (in note 37) 486.
stage.39Sample 31 had a very fine cellular microstructure
which differed from the rest.
The vitrification stage, the estimated firing temperature and the open porosity value of the samples are shown
in Table 4. It can be seen that Group I is associated with
higher firing temperaturesand lower porosities, a result
that accords with these samples having a cellular microstructure of the more closed type.40 The Group II samples span a wide range of firing temperatures and
porosities, although subgroup (c) has consistently lower
firing temperaturesand higher porosities than Group I.
The colors of the amphoras belonging to Group I are
darker than those of Group II; within the latter the color
39. Ibid. 486.
40. The porosity of 10 is rather high for its very vitrified microstructure (TABLE 4); assuming there was no error in the porosity measurements (the available sample was rather small), the exceptionally
heavy tempering of this sherd could be responsible for the result obtained.
Journal of Field ArehaeologylVol. 11, 1984
219
Figure9. (a) SEM micrographof 22
(GroupII) in the ''as receivedstate"
showingcharacteristiccalcareousopen
structure.(b) SEM micrographof 6
(GroupI) in the ''as receivedstate''
showingmorevitrifiedand denser
microstructure.
(c) SEM micrographof 9
afterrefiringat 1080°C, showingcoarse
vitrifiedmicrostructure.
Whitebar in
each photographrepresents10F.
a
b
c
220 Punic Amphorasat Corinth:Originand TechnologylManiatis
et al.
varies from red (low fired) to light brown (high fired).
This finding is not unexpected since above 850°C, when
solid-state reactions begin to take place, iron is diluted
in the newly formed calcium-aluminosilicate phases, and
this results in the dissociation of the red haematite particles, which were formed up to that temperature, and in
the bleaching of the red color.4l
The results of SEM suggest that the two groups of
amphoras were the products of different ceramic technologies. Group I was fired predominantly in reducing
atmospheres (as witnessed by the Mossbauer results) and
at higher temperatures;it contained less calcium, it produced a more glassy and closed microstructure and it
was heavily gritted. Group II, by contrast, displays a
range of colors and firing temperatures,but the porosities
are generally high, as are the calcium contents, resulting
in light and soft wares.
Finally, the sherds refired at 1080°C exhibited much
more vitrified microstructure(FIG. 9c) with a slight variation in the extent of glass formation. These variations,
however, did not correlate with the types of microstructure observed in the ASk samples.
Discussion
The results of all the techniques employed, apart perhaps from SEM, point towards the existence of two kinds
of clay for the production of the Punic amphoras. The
classification of the samples derived from the four techniques listed in Table 5 is, with few exceptions, entirely
consistent.
The chemical compositions determined by optical
emission spectroscopy divide into two types of clay according mainly to the structural elements, Fe and Al.
Mossbauer spectroscopy reveals that these two clays or
groups of clays behave differently on firing at higher
temperatures. The petrological basis of the two groups
has also been defined: one clay contains inclusions of
sedimentary origin and the other contains metamorphic
temper; among the five subgroups within the former,
II a, II b, and II c probably reflect temperatureand minor
tempering differences, while II d and II e present an
interesting mixture of sedimentary and low-grade metamorphic temper. X-ray radiography highlights the high
concentration of dense inclusions in the metamorphic
group. Finally, SEM and porosity measurements have
provided information on the firing techniques employed,
and they also suggest the existence of at least one consistent technology (Group I) and one or more different
ones (Group II).
41. Chevalier et al., op. cit. (in note 20) 861-865; Maniatis et al.,
op. cit. (in note 19) 263-269.
Table 5. A comparison of the classification of the amphoras
according to (1) chemical analysis, (2) Mossbauer
spectroscopy, (3) X-ray radiography, and (4) petrological
analysis.
Mossbauer X-ray
PetroChemical Spectros- Radiog- logical
Sample Analysis copy
raphy Analysis
6
9
10
4
15
30
11
<, < 8
g 27
u) 16
X 31
*; 14
;
19
;, 2
O i22
12
13
26
24
18
20
28
2S
23
21
29
17
7
1
3
S
I
I
I
I
I
I/II
I
I
I
I
I
I
I
I
I
I
I
I
I
I
II
II
-
I
I
I
I
I
I
I
I
I
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
I
I
I
I
IIe
IId
II
I/II
I/II
I/II
I/II
I
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
I
IIe
IId
IIc
IIb
IIc
IIe
II
II
II
II
II
II
II
II
II
II
II
II
II
II
II
IIc
IIc
IIb
IIb
IIa
IIb
IIa
IIc
IIc
IIc
With these data it is now possible to correlatethe
classificationsdeterminedinitiallyby hand-specimenexaminationwith those derivedfromthe variousanalytical
techniques,especiallypetrologicalanalysis.Thatthe two
maingroups,I' and II', separateaccordingto color is a
reflectionof the use of two generaltechniquesof manufactureeither in the same or in differentworkshops;
overall reducing and oxidizing atmospheresseem to
characterizethe two techniques;GroupI' of the handspecimenexaminationcorrelateswell with petrological
GroupI. Sample11 containssedimentaryinclusionsand
notablyfewer low-grademetamorphicmineralsthanthe
membersof GroupI', but it has the characteristicdark
color in hand specimen. Sample 10 is unusual,but it
only appearsto differ from the othersin GroupI' from
Journal of Field ArchaeologylVol. 11, 1984
the technological point of view rather than in its mineralogical composition. The subgroups of Groups II' and
II also correlate well with the exception of two samples,
16 and 22, which together with 11 form II e. It is clear
that the features noted in hand-specimen examination
reflect with reasonable accuracy the tempering material
in the pottery, and, as a result, it should be possible for
the archaeologist to give a general fabric classification
without the need for detailed petrological analysis. Such
a classification would be useful in the field, for example,
although the presence of anomalous samples argues for
some caution in using it for more precise definition.
One last point concerns the contrasting physical properties of the two main groups. The amphoras in Group
I were fired at consistently higher temperatures(in rather
reducing atmospheres) than those in Group II, and they
have slightly lower Ca contents and lower porosities; that
they were heavily tempered was necessary to increase
their strength and durability.42The Group II amphoras
are lighter and more porous, resisting thermal and mechanical shock better; these properties were achieved irrespective of firing atmosphere in the temperaturerange
850 to 1000°C . 43
Conclusions
The value of this study can be judged at two levels;
first it has answered many of the archaeological questions about the Punic amphoras found at Corinth, and
second it has demonstratedan importantmethodological
aspect of archaeological science, namely, that the data
obtained from several techniques have collectively produced a full physico-chemical description of this type of
amphora. We have shown how the classification of this
material by the provenance-orientedtechniques of chemical and petrological analysis has been extended and
strengthened by the application of Mossbauer spectroscopy and SEM. The value of Mossbauer spectroscopy in
detecting the different behavior of two groups of clays
should be emphasized; in addition, X-ray radiography,
which has not hitherto been used much in this type of
work, proved useful.
In concluding, we have established that the compositions are consistent with the amphoras being manufac42. The presence of calcium oxide contents greater than 9%, however, may appear to conflict with the formation of iron oxides (detected by Mossbauer spectroscopy) and the consequent nonformation
of calcium aluminosilicates. There are two possible explanations;either
the calcite particles are large and do not participate in the solid-state
reactions forming calcium aluminosilicates (Maniatis and Tite, 1981
op. cit. [in note 37] 65), or the only calcium aluminosilicate mineral
formed is a more glassy body, an observation that was verified by the
SEM examination of the Group I samples.
43. Maniatis and Tite, 1978 op. cit. (in note 37) 491.
221
tured at a single or neighboring centers. Furthermore,
the coexistence of low-grade metamorphic, together with
sedimentary, fragments in a number of the amphoras
(Groups II d and II e) indicates that both sources of
temper were used simultaneously by the same potter.
Although it has not been possible to determine the precise location of these centers, the geology of the NW coast
of Morocco to the Straits of Gibraltarand the coast opposite on Spain can accommodate both the clay and temper of the amphoras.
Wherever the amphoras were made, the nature of the
two technologies is indicative that one ware was probably good enough for carrying fish in oil or brine, its
quality being very consistent, while the second ware was
very porous, suitable only for dry contents. Although the
observed range of colors among the amphoras may represent no more than the variations in the firing conditions, it is possible that different colors were deliberately
achieved in order to signify content. Furthermore, since
all the fish found in the Punic Amphora Building at Corinth were filleted, it is possible that a portion or type of
such fish was shipped dried or salted in amphoras fired
in one way, while other fillets were perhaps shipped in
oil or brine within amphoras produced in the same area
but under different conditions. What light this reflects
upon ancient tastes, menus, and national customs, however, it yet to be investigated. The present findings undoubtedly provide scope for further research.
Appendix
1. Discussion of Minerals
The quartz frequently displayed undulose extinction
up to about 20°. The grains also contained vacuoles (air
and liquid bubbles), and inclusions of rutile and zircon.
It is possible that at least some of the very fine sand and
silt-sized grains were derived from the breakdown of
polyciystalline grains. The term "polyciystalline quartz"
has been applied to those grains composed of several
quartz crystals that did not show the parallel orientations
that clearly identify schist, although this may well have
been their source.
The feldspars were often slightly weathered. In many
cases the orthoclase was the bearer of microperthitic intergrowth. The plagioclase was often twinned with respect to the albite or Carlsbad laws. The identification
of the cordierite required particular care owing to its
similarity to quartz and feldspar under the microscope.
Both the chlorite and the amphibole(?) were strongly
pleochroic, the colors ranging from yellow to pale green
in the former and brown to dark green in the latter. The
yellow and brown color of minerals is frequently produced or enhanced through the effects of firing. The
et al.
222 Punic Amphorasat Corinth:Originand TechnologylManiatis
stronger body color then tends to mask the interference
colors. In many cases the chlorite had become cloudy
because of alteration, possibly as a result of firing. The
pyroxenes were present only in very small quantities and
consequently their identification can only be regarded as
tentative until many more samples have been analyzed.
Lime refers to the minute crystals of calcium minerals
that were scattered throughout the matrix of most of the
fabrics and often lined the rims of voids.
2. Discussionof the RockFragmentsand the
Sourcesof the Temper
The rock fragments point towards sedimentary and
metamorphic sources for the temper. The metamorphic
fragments consisted of biotite and muscovite schist and
amphibole(?) schist. In one fragment of schist, biotite,
chlorite, and amphibole were all present, while in another garnet and muscovite were both present. Chlorite
and plagioclase formed one type of rock fragment found
in subgroup (e), while white mica, quartz, and kyanite
formed another. Subgroups (d) and (e) were the richest
in serpentinite (usually brown from the effects of firing).
With respect to the metamorphic rocks it is the coexistence of mineral phases in equilibrium (a mineral paragenesis) that defines the metamorphic grade and
environment. As Winkler44points out, however, the precise relationships between mineral phases must be established before interpretationbased on parageneses can be
made. Consequently, the attributionof the metamorphic
material to a particular grade and environment depends
solely upon the interpretation of the rock fragments
whenever these are available. The assemblages described
above appearto belong to environments ranging between
low- and high-grade regional metamorphism.45In general, the metamorphic inclusions in the sedimentary fabrics belong to the low grade, although rare intrusive
examples of the higher grades do occur. The reasons for
the mixing of low-grade (chlorite) and medium- to highgrade material (kyanite, sillimanite) cannot be explained
without detailed knowledge of the geology of the source
region. It is possible that it occurred during transportof
weathered rock fragments by natural agencies.
Acknowledgments
It is with great pleasure that we are able to thank the
Greek Archaeological Service, the Archaeological
Ephoreia of the Argolid and the Corinthia and, espe44. H. G. F. Winkler, Petrogenesis of Metamorphic Rocks (Springer
Verlag: New York 1979) 28.
45. F. J. Turner and J. Verhoogen, Igneous and Metamorphic Petrology (McGraw Hill: New York 1960) 531-560.
cially, Dr. G. Dontas, Inspector General of Antiquities
in 1979, for granting those permissions that were needed
in order that the present researches could be conducted.
Y. Maniatis,A. Kostikas,and A. Simopoulos,
membersof the PhysicsDepartmentat N.R.C.
Demokritos,have been engagedfor manyyears in
researchinto thephysicalpropertiesof clays and their
relationshipto archaeologicalceramicsusing
Mossbauerspectroscopyand scanningelectron
microscopy.
R. E. Jones has been directorof the Fitch
Laboratorysince 1974.
I. K. Whitbreadis workingin collaborationwith the
CorinthExcavations,makinga petrologicalstudy
principallyof Corinthianamphorafabrics. He is
currentlyin the Departmentof Archaeologyat
SouthamptonUniversity.
Ch. Karakalosdirectsthe X-ray radiographyunitat
N.R.C. Demokritos.
C. K. Williams,II, has been the directorof the
CorinthExcavationssince 1967.