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Sourcing flint from Sweden and Denmark
A pilot study employing non-destructive energy
dispersive X-ray fluorescence spectrometry
Richard E. Hughes1, Anders Högberg* 2 & Deborah Olausson3
* Corresponding author (anders.hogberg@malmo.se)
1 Geochemical Research Laboratory, 20 Portola Green Circle, Portola Valley, CA 94028, U.S.A.
2 University of Lund and Malmö Heritage, Department of Archaeology and Ancient History,
University of Lund, Box 117, SE-221 00 Lund, Sweden
3 Department of Archaeology and Ancient History, University of Lund, Box 117, SE-221 00 Lund, Sweden
is article presents the results of a pilot study exploring the feasibility of using
non-destructive energy dispersive X-ray fluorescence (EDXRF) spectrometry
for the chemical sourcing of flint from three geographical areas: eastern Den-
mark and southwestern Sweden (Stevns Klint, Møns Klint, Södra Sallerup),
south and southwestern Sweden (Klagshamn, Östra Torp, Smygehuk) and
southeastern Sweden (Hanaskog). e EDXRF results showed that the flint
samples from Stevns Klint are all chemically alike on the basis of Si/Ca/Fe and
Ca/Fe ratio data, even though they possess markedly different visual qualities
and are of different geological ages. e samples from Södra Sallerup, Sweden,
and Stevns Klint, Denmark, are chemically similar. Since the chalk slabs at
Södra Sallerup were re-deposited by glacial ice, the results of the chemical anal-
ysis may indicate that they originated from the same formation that emerges
at Stevns Klint. e samples from Klagshamn, Östra Torp and Smygehuk are
visually alike and bear the same chemical signature; all three originate from the
same geological formation of Danian age but are from different localities. e
Common Kristianstad Flint (Hanaskog) is distinctive in appearance and the
results of the EDXRF instrumental analysis yielded a corresponding unique
Ca/Fe chemical signature. In summary, the pilot study successfully revealed
distinctions among the flint samples.
Keywords: flint, chemical sourcing, energy dispersive X-ray fluorescence
(EDXRF) analysis, south Sweden, Denmark
Journal of Nordic Archaeological Science 17, pp. 15–25 (2010)
Archaeologists have long been in need of reliable and
replicable means to identify the specific sources of the
raw materials used to manufacture archaeological arte-
facts. In Scandinavian archaeology, Carl Johan Becker
(1952) made one of the first efforts to establish reliable
criteria for differentiating Scandinavian flint types
so that the origins of the raw material sources for the
Neolithic flint axe hoards in northern Sweden could
be identified. Becker relied on appearance and physical
qualities to narrow down the origin of the flint to the
Senonian deposits of eastern Zealand or southwestern
Scania (Becker 1952:69; Knutsson 1988:51). In a re-
cent study of Late Neolithic daggers, Jan Apel (2001)
drew on Becker’s results to advance far-reaching con-
clusions about manufacturing centres and exchange
systems. Other studies have focused on the availability
and use of different flint sources and outcrops on a lo-
cal or regional level (Högberg 2001, 2002; Knarrström
richard e. hughes, anders hgberg & deborah olausson
2001; Carlsson 2004).
e terms “flint” and “chert” are often used inter-
changeably and there is a lack of consensus among ar-
chaeologists as to what to call fine-grained, knappable
siliceous rocks. Some regard flint as a type of chert,
others consider flint to be one type of rock and chert
another (Luedtke 1992). In this article we follow the
Scandinavian practice and refer to all chert varieties
as flint.
ere are two ways to identify the primary source
of a piece of flint: 1) based on optical, or macroscopic,
properties of the material, and 2) via instrumental
analyses of chemical composition. Although many
Scandinavian archaeologists have addressed questions
concerned with the origins of flint as a raw material,
most conclusions have been based on macroscopic
properties, which tend to be described subjectively
and can be altered significantly by post-depositional
knapping and/or patination. A recent study of Scan-
dinavian flint (Högberg & Olausson 2007) illus-
trates the variety and complexity of this material and
demonstrates the difficulties involved in arriving at a
wholly satisfactory macroscopic classification based
on morphology alone.
is article presents the results of a pilot study
which explores the feasibility of using non-destructive
energy dispersive X-ray fluorescence spectrometry
(EDXRF) for the chemical sourcing of flint from
southern Sweden and eastern Denmark. At the outset,
it is necessary to clarify what we mean by “source”,
a term that has been used in a variety of ways in ar-
chaeology (for a discussion, see Hughes 1998). From
the standpoint of instrumentally-based analyses, the
term source usually refers to a distinct entity – a ba-
salt, andesite, obsidian, chert or flint – defined on the
basis of unique combinations and concentrations of
chemical constituents (Hughes 1986:49) that may be
differentially bounded in space. In obsidian sourcing
research, sources are defined geochemically, by their
chemical composition rather than by their spatial ex-
tent (Hughes 1998:104). In western North America,
for example, some chemically discrete obsidian sourc-
es occur over a very small geographical area, perhaps
only a few kilometres, while artefact-quality obsidian
formed in ash-flow tuff sheets in adjacent geographical
areas may occur widely over an area of perhaps 10 000
square kilometres (Hughes & Smith 1993). Scandina-
vian flint chemical types occur over even larger areas.
Consequently, we use the term “source” interchange-
ably with “chemical type” to underscore chemical co-
herence, not spatial distribution.
Optical Methods
Optical methods, appealing to the observable physical
properties of specimens, are of course the fastest and
least costly way to assign a flint artefact to a source.
Becker’s (1952) classification relied on visual qualities,
as does the system proposed recently by Högberg and
Olausson (2007). Although it is generally possible to
distinguish among Scandinavian flint types using vari-
ables such as colour, cortex morphology, translucency
and homogeneity, it is clear that there is some overlap
and ambiguity involved in any optical classification
system (Bettinger et al. 1984). e classification pro-
posed by Högberg and Olausson (2007) is based prin-
cipally on the appearance of primary flint augmented
by observations made at the various primary sources
visited in the course of the study. However, the ap-
pearance of flint can be seriously altered by post-depo-
sitional weathering and patination (Luedtke 1992). In
some cases the appearance of the cortex or the transi-
tion between the cortex and the flint are the main di-
agnostic feature. When this is absent it may be impos-
sible to distinguish visually between two types (Fig.
1). Högberg and Olausson (2007) also show that the
same type of flint can sometimes occur at a number of
separate locations.
In an earlier attempt to identify flint on the basis
of appearance, Lis Ekelund Nielsen (1993) was able
to distinguish reliably between three varieties of flint
used for the manufacture of Neolithic axes on Jutland
by employing a combination of visual characteristics
(mostly colour, texture and fossils), thin sections and
examination at 25–50x magnifications under a stereo-
microscope to support her classification. Kinnunen et
al. (1985) and Tralau (1974) have attempted to iden-
tify flint sources on the basis of their fossil content, but
because not all types of Scandinavian flints contain
recognizable fossils, this method is of limited value.
Instrumental Methods
Although various geochemical analyses of chalk flint
have been carried out in England and the Netherlands
(de Bruin et al. 1972; Sieveking et al. 1972; Craddock
et al. 1983; Bush & Sieveking 1986; Gardiner 1990;
McDonnell et al. 1997), no systematic work has been
done to characterize the geochemical composition of
Scandinavian flint sources. A chemical analysis of spec-
imens of Senonian flint from Stevns Klint, Denmark
showed that it consisted of 98.44% SiO2 (Micheelsen
1966:308). In order to identify flint artefacts found at
edxrf sourcing flint from sweden and denmark
Finnish Stone Age and Bronze Age sites as being made
either of “eastern” (i.e. Russian) or “western” (i.e. Dan-
ish or Swedish) flint, Matiskainen et al. (1989) used
atomic absorption spectrometry to analyse 71 samples
for 20 chemical elements, and succeeded in distin-
guishing between these two broad source categories
on the basis of five elements. Subsequently, Costopou-
los (2003) tested new elemental composition data on
the same samples using an electron microprobe and an
energy dispersive spectrometer and arrived at a similar
conclusion.
As with optical characterization, there are problems
associated with instrumental methods. e instru-
mentation required to carry out the analyses is expen-
sive and the work requires specialist knowledge. Costs
can be high and the analysis generally requires close
cooperation between the archaeologist and the ana-
lyst. Bush (1976:48) lists the following prerequisites
for successful identification of a chert source by trace
element analysis, but these strictures also apply to the
use of other (major, minor and rare earth) elements:
e material from each source must not vary 1.
widely in its trace element composition.
e trace elements used should be ones that 2.
will be uniformly distributed through the
chert and not likely to be concentrated in
occasional rare mineral grains.
e “fingerprint” of each source, i.e. its 3.
composition in terms of trace elements,
must be sufficiently distinct to allow for dif-
ferentiation between sources.
While the actual elements used to construct source-
specific chemical signatures (sensu Hughes 1998:104)
may vary from region to region depending on the com-
positions of the materials studied, the combinations of
elements must be sufficiently clear-cut to distinguish
among the possible outcrops/sources in any particular
area (cf. Malyk-Selivanova et al. 1998:679).
e Flint Problem
Because of the way they are formed, flints in chalk and
limestone can be assumed to fulfil the three require-
ments listed by Bush (1976). Since flint is composed
mainly of SiO2, one approach has been to measure the
trace elements whose origins are non-carbonate ma-
terials (e.g. clay minerals and heavy minerals) which
Figure 1. An example illustrating the difficulty of visually distinguishing among different types of flint. The Grey Band Danian
Flint (Högberg & Olausson 2007:104ff) to the left can be found on northern Jutland in Denmark and in southwestern
Scania in Sweden. It has a characteristic grey band at the transition between the flint matrix and the cortex. If this flint is
knapped so that the cortex and grey band are removed, it becomes difficult to distinguish it on visual qualities alone from
the Scandinavian Senonian Flint (to the right), for example (Högberg & Olausson 2007:88ff). Scandinavian Senonian Flint
can be found in northern Jutland and on Zealand in Denmark and in southwestern Scania in Sweden.
richard e. hughes, anders hgberg & deborah olausson
were incorporated in the flint as it was being formed
by the replacement of calcium carbonate with silica
(Tite 1972:308). e impurities present in a specific
flint are a reflection of many factors, including the
types of rock present in adjacent land masses, weather-
ing processes affecting these rocks, the nature of the
processes transporting sediments into bodies of wa-
ter, the chemical conditions in the deposition basin,
and the distance between the basin where the flint was
forming and dry land (Luedtke 1992:36). e flints
in the north European Maastrichtian chalk and the
Danian limestone were formed by the replacement of
calcium carbonate in a molecule-to-molecule process,
resulting in the preservation of the non-carbonate ma-
terial that existed in the chalk/limestone. It is this non-
carbonate material that served as the prime source
of trace elements in the flint. e chalk in any par-
ticular horizon is generally uniform in composition,
but there are nonetheless significant chemical varia-
tions with time between horizons, so that one horizon
should be discernable from another (Sieveking et al.
1972:156; Bush 1976:48; Craddock et al. 1983:138;
Bush & Sieveking 1986:134; McDonnell et al. 1997).
Parts of a formation that were closer to the source of
sediments, were covered by shallower water, or were
deposited in water with somewhat different pH or oxi-
dizing/reducing conditions may nevertheless differ in
some ways from the rest of the formation, although
they may be similar in other ways (Bush & Sieveking
1986:134; Luedtke 1992:55).
rough the entire Late Cretaceous-Danian time
interval the land masses surrounding the Danish Basin
were flat and low-lying and the climate was arid. As a
result, very little terrigenous material reached the shal-
low epicontinental sea in northwestern Europe (Sur-
lyk & Håkansson 1999). Because of this, Scandinavi-
an flints contain low concentrations of trace elements,
which place high demands on analytical methods. Ide-
ally, these must be capable of detecting a large suite of
elements, even when these elements occur at very low
concentrations. Traditional analytical methods such
as X-ray fluorescence, PIXE or NAA have previously
yielded variable results when employed for flint sourc-
ing (Craddock et al. 1983:138).
Primary and Secondary
Flint Sources in Scandinavia
Flint can be found in primary deposits in Denmark
and in southern Sweden, where there are numerous
outcrops of Danian, Maastrichtian and Campanian
age. ese sources were exploited in situ by prehistoric
people to varying degrees, either through mining ef-
forts or by taking advantage of flint layers eroding out
of cliff faces. e primary sources were then aug-
mented by secondary ones located in glacial moraines
and on beaches, where ice movements had excavated
flint from primary sources and redeposited it, creating
a complex mixture of different flint types over large
parts of the region. Provenance determinations in
Scandinavia are therefore greatly complicated by the
geological conditions, which have made large quanti-
ties of secondary flint available to prehistoric popula-
tions on beaches and in glacial till (Högberg & Olaus-
son 2007). e instrumental sourcing methods in use
today can tell us the primary source of the flint we are
investigating, but they do not enable us to distinguish
between primary and secondary sources. Once the
primary sources have been successfully defined, there
may be further difficulties connected with linking a
piece of flint (or a flint artefact) from a secondary con-
text with one of the primary sources.
For the geochemical fingerprinting of flint to be
useful in sourcing archaeological artefacts, it must be
assumed that the flint composition remain unaltered
by exposure to soil, weathering, or other processes for
the long periods of time for which the flint remains
were exposed at the surface (Bush 1976:48; Rapp
1985:355; McDonnell et al. 1997:372). Luedtke
(1992:57) and acker & Ellwood (2002:476) cau-
tion against using cortical or weathered surfaces of
samples for geochemical sourcing, since flint is sus-
ceptible to a number of post-depositional processes
which can alter their internal chemistry. Only a few
systematic studies have been carried out to test this
assumption, however. In one such study, de Bruin et
al. (1972) used non-destructive NAA to measure el-
ements in flint from several north European sources
and found when comparing the results for nodules
in the Rijckholt mine in the Netherlands with those
for flint flakes from the workshop outside the mine
that the Rijckholt mine and workshop specimens
were not chemically identical. eir conclusion was
that the chemical composition of the flakes had been
altered by the depositional environment (de Bruin et
al. 1972:63). However, Bush (1976:48) writes that
chalk cherts (flints) are dense and of low permeability,
which reduces the possibility of trace elements being
removed by leaching or of material being added from
the groundwater.
e conclusion to be drawn is that geochemical
analyses of flints from secondary contexts may be
complicated and the prospects of identifying the pri-
mary source for any given artefact may be problematic.
edxrf sourcing flint from sweden and denmark
Nevertheless, the first order of business is to generate
a chemical “fingerprint”, or chemical profile, for each
known primary source. Once that step is completed,
one may find that the geochemical signature of a sec-
ondary flint occurrence matches that of one of the
primary sources (prompting one to conclude that the
flint came from that source), or that it may not match
any of the known sources.
However, even assuming we are able to achieve a
successful characterization of the primary sources,
geochemical analysis alone cannot tell us whether the
flint was collected or mined directly from the outcrop
in question or whether it was derived from a nodule in
a secondary geological deposit that was “mined” by a
glacier (Williams-orpe et al. 1999:210). A possible
method for making this distinction has been described
by Shockey (1995), who used polarization to distin-
guish between quarry area specimens and stream-
rolled rocks representing the same material.
Geochemical Analysis of Scandinavian Flints
In an attempt to find a reliable method for chemically
characterizing Scandinavian flint sources, Högberg
and Olausson initiated a study of flint from ten geo-
logical contexts. A total of 119 nodules were collected
from the ten localities in southern Sweden and Den-
mark (Table 1, Fig. 2) and samples from these nodules
were submitted for geochemical analysis.
Several methods were tested: Laser Ablation Induc-
tively Coupled Plasma Mass Spectrometry (LA-ICP-
MS), Inductively Coupled Plasma-Optical Emission
Spectroscopy (ICP-OES) of solutions, ICP-MS of
solutions and Energy Dispersive X-ray Fluorescence
(EDXRF). LA-ICP-MS can provide compositional
data on 50–60 elements, while the other techniques
typically provide compositional data on 30 elements
or less (Speakman et al. 2002). Laser ablation ICP-
MS has lower detection limits for many elements than
do the other instrumental techniques (Gratuze et al.
2001; Speakman et al. 2002), and this method has
been used successfully on English chalk flint (Rock-
man pers. comm. 2002). EDXRF typically measures
fewer elements than ICP techniques, and with a lower
precision, but it can rapidly generate data for a large
number of elements without sacrificing any portion of
the sample for analysis (Giauque et al. 1993).
Only the last of these methods proved effective for
the present samples. Before we describe the successful
results we achieved using EDXRF, we will briefly de-
scribe the difficulties we encountered with the others.
Laser Ablation Inductively Coupled Plasma Mass
Spectrometry (LA-ICP-MS) and Inductively Coupled
Plasma-Optical Emission Spectroscopy (ICP-OES)
A total of 360 flake samples taken from the 119 flint
nodules were submitted to the Research Reactor
Table 1. Source, description, type of flint according to Högberg and Olausson (2007) and samples included in the study.
Source Description Type of flint Sample
Östra Torp An abandoned modern limestone quarry. Matte Danian Flint, Östra
Torp Variety
Ten flint nodules collected from a
quarry dump.
Klagshamn An abandoned modern limestone quarry. Matte Danian Flint, Östra
Torp Variety
Ten flint nodules collected from a
quarry dump.
Stevns
Klint
A Maastrichtian chalk and Danian limestone
cliff by the sea.
Matte Danian Flint, Östra
Torp Variety and Scandi-
navian Senonian Flint
Ten flint nodules from each of two
layers of Danian age and ten nod-
ules from one layer of Senonian age,
all collected in situ.
Smygehuk An outcrop on a beach. Matte Danian Flint, Östra
Torp Variety
Ten flint nodules collected from the
outcrop.
Södra
Sallerup
Large chalk slabs containing flint which were
scooped up by glacial ice and re-deposited
at the site. Systematic mining of flint started
here in the Early Neolithic, and chalk quar-
rying has continued until quite recently.
Scandinavian Senonian
Flint
Ten flint nodules collected in situ
from dumps at the modern quarry.
Møns
Klint
A Masstrichtian chalk cliff by the sea. Scandinavian Senonian
Flint
Twenty nodules from each of two
flint layers.
Hanaskog An abandoned modern limestone quarry. Common Kristianstad
Flint
Nine nodules collected from quarry
dumps.
richard e. hughes, anders hgberg & deborah olausson
Center at the University of Missouri-Columbia for
LA-ICP-MS. Laser ablation ICP-MS requires little
sample preparation other than resizing to fit inside
the sample chamber. e samples were washed in
deionized water and left to dry. Each sample was then
crushed into coarse fragments, and relatively flat in-
terior fragments with little or no cortex were selected
for analysis.
e results showed that the samples had a high
silica concentration, which unfortunately resulted in
dilution of the other elements. e conclusion was
that this method, as employed under existing analyti-
cal conditions, was unsuitable for characterizing Scan-
dinavian flint types (Speakman et al. 2002; Speakman
pers. comm. 2004).
Samples from the same nodules were subsequently
analysed by Inductively Coupled Plasma-Mass Spec-
troscopy and Inductively Coupled Plasma-Optical
Emission Spectroscopy (ICP-MS and ICP-OES) of
solutions at the Analytical Unit of the University of
Figure 2. Map of south Scandinavia showing the sources of flint mentioned in the text. The distance between Klagshamn
and Hanaskog is approximately 125 km.
edxrf sourcing flint from sweden and denmark
Greenwich. Sample preparation for this method in-
volved crushing the flakes and then milling them to
a fine powder. 0.5000 g of each powder was then dis-
solved in acid and heated to near dryness. is proce-
dure was repeated twice, and finally the powder was
dissolved in nitric acid. is approach resulted in the
removal of Si from the flint and dissolving of the re-
maining flint (Wray 2005).
e results indicated that the samples were quite
homogeneous within each respective layer or locality,
while the layers and localities were distinct from each
other (Wray pers. comm. 2006). Further sampling and
more detailed analyses would be necessary, however,
before definitive geochemical compositions could be
established for the sources using these methods.
Energy Dispersive X-ray Fluorescence Analysis
(EDXRF)
Because of the obvious importance of artefact conser-
vation in archaeology, neither ICP-MS nor ICP-OES,
being destructive methods, is ideally suited for use in
artefact provenance studies. Although X-ray fluores-
cence analysis has been applied with great success to
the study of volcanic rocks such as obsidian (e.g. Jack
1976; Reeves & Ward 1976; Stross et al. 1976; Nelson
1984, 1985; Hughes 1986; Asaro et al. 1994; Shack-
ley 2005; Iovino et al. 2008; Hughes & Lucas 2009),
it has not to our knowledge been as widely used on
sedimentary rocks such as chalk flint. EDXRF has
certain other advantages in addition to being a com-
pletely non-destructive method. Its precision for trace
and rare earth element measurement is not as good
as that of ICP-MS or ICP-OES, but its sensitivity to
certain low atomic number major elements (e.g. Al,
Si, K, Ca, and Fe) allows measurements of these to
be used in combination to identify contrasts among
certain Scandinavian flint types.
Instrumentation and Results
To determine whether or not non-destructive EDXRF
would be useful for the characterization of Scandina-
vian flints, a sample of five flakes detached from dif-
ferent nodules recovered from each of ten collection
localities (including three separate layers at Stevns
Klint and two at Møns Klint) was analysed (see Table
1 and Fig. 2 for locations). e instrumental analy-
sis was performed by Hughes using a QuanX-EC™
(ermo Electron Corporation) EDXRF spectrom-
eter equipped with a silver (Ag) X-ray tube, a 50 kV
X-ray generator, a digital pulse processor with auto-
mated energy calibration and a Peltier cooled solid
state detector with 145 eV resolution (FWHM) at 5.9
keV. e X-ray tube was operated at various voltage
and current settings to optimize the excitation of the
elements selected for analysis.
Sample pretreatment for the whole rock EDXRF
analyses was limited to cleaning with distilled water
to remove any noticeable surface contaminants. Spe-
cial care was taken to avoid directing the X-ray beam
onto obvious patinated surfaces (see above) or calcare-
ous or fossil inclusions. e only other requirement
was that each sample should be relatively flat, > c. 2–3
mm thick and >15–20 mm in diameter. Although no
analyses were performed here on flint artefacts, the
same size parameters should apply to archaeological
specimens as to geological samples.
Initial analyses were conducted for the trace ele-
ments rubidium (Rb Kα), strontium (Sr Kα), yttrium
(Y Kα), zirconium (Zr Kα) and niobium (Nb Kα),
but it quickly became apparent that these data could
not be employed because the peak/background counts
were far lower than the element-specific detection lim-
its of EDXRF. A second set of experiments included
analyses for Al, Si, K, Ca, Ti, Mn and Fe (using the Kα
emission line for each element) but, as with the above
trace elements, the extremely low number of X-ray
emission counts/second generated for Al, K, Ti and
Mn indicated that these elements similarly would not
yield reliable data. Subsequent experiments focused on
Si, Ca and Fe, as these generated much higher count
rates (counts/second over the background). e analy-
ses for Si, Ca, and Fe were conducted at 30 deadtime-
corrected seconds in order to generate background-
subtracted integrated net count rate (counts/second)
data. Overlapping Kα and Kβ line contributions from
adjacent elements were stripped, and the tube current
was scaled automatically to the physical size of each
specimen. Although these experiments employed in-
tegrated count rate data, the typical 2σ quantitative
analysis measurement precision for SiO2, Ca and Fe
was 1–2% relative.
A ternary diagram plot for the 50 specimens exam-
ined by EDXRF in this pilot study is shown in Fig-
ure 3. As expected in the light of the data published
by Micheelsen (1966), all the samples contained
relatively high amounts of SiO2, but the variations in
Ca and Fe composition allowed the flints to be parti-
tioned into two general groups, one consisting of the
samples from Smygehuk, Östra Torp and Klagshamn
and the other of those from Møns Klint, Stevns Klint
richard e. hughes, anders hgberg & deborah olausson
and Södra Sallerup. e samples from Hanaskog plot-
ted close to the latter group, although this source was
found to contain a higher proportion of Fe.
A bivariate plot of Ca vs. Fe (Fig. 4) provides a
somewhat clearer picture of these chemical relations
by removing the high Si from the picture. e same
two-part separation as was documented in Figure 3
also appears in Figure 4, but with some refinement. In
this case a relatively high Ca group (made up of Smy-
gehuk, Östra Torp and Klagshamn) and a group with
relatively low Ca and Fe (consisting of Møns Klint,
Stevns Klint and Södra Sallerup) are apparent, while
Hanaskog is clearly distinguished from both of these
other two groups on the basis of its relatively higher
Fe.
e reader will have immediately noticed that
these provisional chemical groupings are to a certain
extent geographically discrete. e Smygehuk, Östra
Torp and Klagshamn localities are all in southwestern
Scania, Sweden, Hanaskog is in northeastern Scania,
Sweden, and Møns Klint, Stevns Klint and Södra
Sallerup are in eastern Denmark and southwestern
Scania (see Fig. 2). It is notable that, although Klag-
shamn and Södra Sallerup are located only about
20 km from one another, the Ca/Fe ratio data show
that flints from these sources represent quite different
chemical types.
Discussion
Luedtke (1992) observed that chemical variation in
chert formations is often correlated with variability
in their visual characteristics. In general, the more
extreme the visible differences within a chert type,
the more extreme the chemical variability (Luedtke
1992:54). e results indicate, however, that this gen-
eralization cannot be reliably applied to the flints we
have analysed.
When we compare the chemical signatures based
on the EDXRF analyses with the geological contexts,
spatial locations and visual qualities of the flint sam-
ples, interesting results appear. e samples from
Stevns Klint are all chemically alike in terms of their Si/
Ca/Fe and Ca/Fe ratio data, yet they possess markedly
different visual qualities and are of different geological
ages. e samples are of both Maastrichtian and Dani-
an ages and are classified visually as representing Scan-
dinavian Senonian Flint or the Östra Torp Variety of
Figure 3. Ternary diagram
plot for the Scandinavian
flint samples.
edxrf sourcing flint from sweden and denmark
Matte Danian Flint.
We note, too, that the samples from Södra Sallerup
and those from Stevns Klint are chemically similar, al-
though the two localities are about 50 km apart. We
know that the chalk slabs at Södra Sallerup are not
in situ. Bertil Ringberg (1980:57ff) has suggested that
they were removed from the floor of the Baltic Sea to
the south and re-deposited in their present location
by glacial ice. It is therefore entirely possible that the
chalk and its flint at Södra Sallerup comes from the
same formation as that which emerges at Stevns Klint,
in which case the origin of the slabs must lie southwest
of Södra Sallerup. Our chemical data are consonant
with this conclusion.
e samples from Klagshamn, Östra Torp and
Smygehuk are visually alike and bear the same chemi-
cal signature. All three originate from the same geo-
logical formation of Danian age but are from differ-
ent localities. e Common Kristianstad Flint (Ha-
naskog) is distinctive in appearance and the results
of our EDXRF instrumental analysis yielded a corre-
sponding unique Ca/Fe chemical signature.
Future work notwithstanding, these pilot study
results reveal distinctions among three geographical
areas: eastern Denmark with southwestern Sweden
(Stevns Klint, Møns Klint, Södra Sallerup), south-
western Sweden (Klagshamn, Östra Torp, Smygehuk)
and southeastern Sweden (Hanaskog).
While we are gratified by these initial research re-
sults, we caution that they are only preliminary. More
samples need to be analysed from these localities to
ensure that the groupings remain discrete, and addi-
tional samples need to be tested from localities not in-
cluded in this study to determine the degree to which
Si/Ca/Fe signatures remain useful for identifying flints
in this part of the world in general. Further work will
also be undertaken to convert the integrated intensity
data to concentration estimates in order to facilitate
comparisons with research conducted at other labo-
ratories.
It should be pointed out that these results are ap-
plicable to fresh, unpatinated surfaces. Since pati-
nation may alter the surface chemistry (Shepherd
1972; Luedtke 1992; Högberg & Olausson 2007),
it is important to investigate whether EDXRF analy-
sis is accurate for patinated flint as well. is will be
the subject of further studies. Our ultimate objective
is to apply these chemical distinctions to the analysis
Figure 4. Bivariate plot
of Ca/Fe composition
for the Scandinavian
flint samples.
richard e. hughes, anders hgberg & deborah olausson
of prehistoric artefacts of different ages to establish
whether or not there was change and/or continuity
through time in material acquisition and conveyance
patterns in different parts of Scandinavia.
Acknowledgements
is paper was revised and expanded from a talk de-
livered at the Department of Archaeology and An-
cient History, Lund University, October 20, 2008.
Economic support was provided by Birgit och Gad
Rausings Stiftelse för Humanistisk Forskning and by
Elisabeth Rausings minnesfond.
English language revision by Malcolm Hicks.
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