Proceedings of the 39th International Symposium for Archaeometry, Leuven (2012) 042-045
Seeing red on the walls of a Roman villa rustica.
A reconstruction of wall decoration through combined mortar and plaster analysis.
B. van Os1, L. Laken2 and L. Megens3
1.
3.
Cultural Heritage Agency, P.O. box 1600, 3800 BP, Amersfoort, The Netherlands,
b.van.os@cultureelerfgoed.nl
2. Radboud University Nijmegen, The Netherlands,
l.laken@let.ru.nl
Cultural Heritage Agency, Hobbemastraat 22, 1071 ZC Amsterdam, The Netherlands,
l.megens@cultureelerfgoed.nl
The residential buildings in some of the villa complexes had
wall paintings as elaborate as those in the urban settings,
with the local elite displaying their wealth in both their
urban and their rural properties (Swinkels 1987; Van
Dierendonck et al. 1988; Laken 2007; Laken 2010; cf. Van
Dierendonck et al. 1991; Laken et al. 2010).
ABSTRACT
In 2008 and 2009 a joint team of the Cultural Heritage
Agency, the municipality of Maastricht and the University
of Amsterdam excavated a Merovingian burial site at
Borgharen, near Maastricht, the Netherlands. For their
burials, the Merovingians used the ruins of a Roman villa
rustica, situated on a high gravel bed in the flood plain of the
river Meuse.
In the case of Borgharen, about 200 mortar pieces were
found in a secondary Merovingian burial context. The
Roman villa was probably still visible during Merovingian
times and served as a clear funerary landmark (Laken et al.).
The soil at the site consists of very coarse gravel, filled in
with rich loamy-clay sediment, creating a subsurface of
natural concrete. It must have proven easier to dig close to
the hypocaust and wall foundations of the Roman villa
rather than the concretized soil. They filled the graves with
more loose, subsoil material that included many fragments
of Roman building material. These burials accidently
preserved the material that has enabled us to investigate a
typical Roman villa rustica.
During the excavation, many small fragments of mortar and
plaster were found. The study of fragmentary paintings
provides examples of provincial-Roman interior decoration
in the Low Countries. Through comparison of Roman villae
rusticae in this area, we can track patterns of Romanization
in the first and second centuries A.D.
This study shows how the chemical characterization of
plaster can aid the identification of fragments and
supplement the traditional macroscopic study of colour,
composition and texture of plaster and mortar layers. For the
Roman villa of Borgharen, we can categorize the remaining
non-identified mortar pieces, which multiply the
possibilities for interpretation of its interior decoration. In
the case of tiny plaster fragments of almost identical colour,
rapid and non-destructive chemical characterization serves
as a valuable addition to the toolkit of the archaeologist.
This study takes the first step toward comparison of Roman
construction and interior decoration techniques at rural
complexes, such as the one in Borgharen, and urban
complexes in the surrounding administrative centres, such as
Tongeren, Cologne, Nijmegen and Xanten.
Material and Methods
KEYWORDS
We have studied nearly 200 plaster fragments, varying from
1cm to 5cm in diameter, of which about fifty were described
in detail. After structural analysis of each fragment (e.g.
thickness of mortar layers, inclusions of organic material
and lime, mineral composition, colour, grain size) we have
distinguished several types and subtypes. In addition, we
have analyzed the painted lime coat of these fifty fragments
as well as 150 non-identified fragments, using pXRF
(portable X-ray fluorescence analyser, Niton XL3t –
GOLDD).
!
Decoration, Roman Pigments, Villa Rustica, Wall Painting.
Introduction
In the southern parts of the Netherlands, especially along the
Meuse river and amid the fertile löss soils of the cretaceous
plateau in Limburg, one finds the ruins of several large
Roman villa rustica complexes. In Roman times, the area
from the Belgian coast to Cologne became densely
populated and large agricultural complexes were
established. Most Roman houses in this region probably
lacked solid stone walls, since natural building stone was
not readily available, but were instead constructed of timber
with wattle and daub infilling. However, the large amounts
of coloured plaster and all sorts
of mortar found at these villa rustica sites indicate that
specialised artisanal workers decorated these complexes.
Results
Mortar
Two mortar types could be distinguished, type A and B.
Type A consists of at least three layers (figure 1):
42
!
A range of red colours were applied to the plaster of type A,
varying from a lighter red made with minium pigments to a
dark burgundy red made with hematite (figure 3). In
addition some of the fragments had grey splatters of zincoxide (figure 4).
!Surface: Thin lime coat
!Layer 1: Pink very coarse mortar, 7-8mm thick with
fine grained and coarse tile or pot fragments, lime
grains. Organic imprints visible between layer 1 and
2 (straw/grass)
!Layer 2: Beige/grey mortar, 11mm thick with
coarse grains from lime, sand, fine gravel (2-9mm):
sometimes black fine sand, straw or grass imprints.
Fig. 3. typical example of subtype A3 a plain burgundy red,
consisting of zinc and lead rich hematite.
!
Fig. 1. typical example of mortar type A with red lead
(minium) pigment (type A1) A, front, B, back and C cross
section.
!
Type B (figure 2) has four layers:
!Surface: White thin lime coat
!Layer 1: Whitish-grey fine-grained mortar,
approximately 5mm thick, containing lime and
sand.
!Layer 2: Whitish-grey fine mortar, approximately
7mm thick, containing lime and sand, lime grains
and fine gravel (2-10mm). Feature: Fine gravel
between layers.
!Layer 3: as layer 2 but 9mm thick without fine
gravel between layers
Fig. 4. typical example of subtype A, burgundy red,
consisting of zinc rich hematite with zinc-rich grey splatters.
!
!
Another end member subtype A6 (figure 5) is a burgundy
red to red coloured plaster with clear brushstrokes, having a
zinc and lead content in between subtypes A4 and A2.
Fig. 2. example of a corner fragment of mortar type B with
most hematite and lime pigment. A, B, C: front (both sides),
D: back and E: cross section.
Nine different subtypes characterize mortar type A,
distinguished by their colour and finish, as described in table
1.
!
Fig. 5. example of subtype A6 with dark lead and zinc rich
haematite and a less dark red ochre without lead and zinc.
43
!
!
Fig. 6 plots the pXRF analyses of iron lead and zinc. Since it
is impossible to calibrate for every surface and thickness of
pigment, pXRF may not provide adequate quantitative
analysis, but still allows for a good comparison between the
fragments.
!
!
!
!
Table 1. Mortar subtypes according to the colour and surface features.
"#$%!
78!
7B!
7?!
7@!
7L!
7N!
7O!
!!
C!
&'(')*!
9*-/5%!:%0!
C)*5)/0#!
$(-4/!>)*5)/0#E!2'6%146%2!F41;!
.*%-6!6'14G%!
>*'F/!*%0!F41;!5*%#!2$(-11%*2!
+)*,-.%!-/0!,%-1)*%2!
26''1;!
26''1;!
!!
4**%5)(-*E!F41;!G424>(%!>*)2;21*'H%2E!.'66'/(#!
>)*/%0!1'!5*%#!'/!1'$!
M;41%!
!!
>)*5)/0#!F41;!1*-/2414'/!1'!*%0! >*)2;21*'H%2E!(-#%*!8!,4/%!5*-4/%0E!(-#%*!B!'/(#!?!
66!1;4.H!
P*%%/!
>*)2;21*'H%2!
!!
!!
F;41%!'*!*%0!'*!F;41%!-/0!>(-.H! !!
(4/%!
3456%/1!
:%0!<%-0!=3>?9@A!
D4/.!-/0!(%-0!*4.;!;%6-141%!
D4/.!-/0!(%-0!*4.;!;%6-141%!
I%6-141%!F41;!5*%#!J4/.'K40%!
!!
<%-0%0!;%6-141%!
&%(-0'/41%Q5(-).'/41%!
!!
&;-(HQ!;%6-141%!F41;')1!D/!'*!3>!!
!!
!
Fig. 6. Relationship between lead and zinc (a), lead and iron (Fe2O3) (b) and zinc and iron (c) for the non categorized
fragments (U), and plaster types A and B. Note that the pigments of mortar type B do not contain lead.
!
In figure 6 we observe a clear correspondence between the
Conclusion
chemical analysis of the painted lime coat and the mortar
type. We distinguish several types of ochre and other
Chemical characterization of plaster aids in the
pigments, applied on at least two different types of plaster.
identification of fragments, complementing traditional
For red pigments they used limonite, two different kinds of
macroscopic studies of colour, composition and texture of
hematite (Zn-rich and Zn-poor) and minium. The most
plaster and mortar.
abundant subtype is A1, with a minium finish. Accordingly,
most of the 150 uncategorized samples fall into this group.
Categorizing the unidentified mortar fragments increased
Concerning fragments of mortar type B, minium was
the probability of interpreting how villa walls were
unattested, suggesting that these come from other walls or
decorated.
rooms. They used at least two different pigments containing
iron oxide. One, the dark burgundy of subtypes A3, A4 and
The use of several types of red pigments suggests separately
A6, was derived from a hematite containing equal amounts
decorated walls or rooms, and the use of minium, non-local
of lead and zinc (figure 6a), the other, more reddish-brown
zinc. Lead containing hematite indicates that pigments were
or reddish-orange (“burnt Siena”) with low lead and zinc
imported. Also, grey splatters rich with zinc indicates that a
content (subtype B), was most likely derived from red,
white zinc was used, which became grey after degradation.
possibly fired, clay.
The proximity of zinc mines in La Calamine, established
during the Roman period (Dejonghe 1998), may have
On other Roman sites in the Netherlands, one finds similar
provided this pigment.
pigments, which suggests that the large rural settlements
were similarly decorated as urban houses (Megens 2007;
The consistent texture and composition of mortar indicates
2008; 2010).
highly skilled, specialized craftsmen, with painted walls as
44
!
Swinkels, L.J.F., 1987, A gladiatorummunus depicted in a Roman
villa at Maasbracht, In: Pictores per provincias, Avenches
(Cahiers
d’ArcheologieRomande
de
la
BibliothequeHistoriqueVaudoise 43), 191-195.
an indication of high status and well established trade
routes. Future research will focus on the relation of rural
versus urban mural paintings and regional differences in
Roman times.
Acknowledgements
We would like to thank Ton Penders for his detailed photos of the
plaster fragments. The help of Mario van IJzendoorn is
acknowledged for cleaning the samples and performing the XRF
analyses of the pieces. We also wish to thank Brien Garnand for his
revision of the English text and his helpful comments on the
various shades of red discussed here.
References
Dejonghe, L. 1998. Zinc–lead Deposits of Belgium. Ore Geology
Reviews 12, 329–354.
Van Dierendonck, R.M., Swinkels, L.J.F. & W.J.H. Willems, 1988.
ReicheGuttsherren in Maasbracht. In: M.E.Th. de Grooth
(red.), Villa rustica. Römische Guttshöf im Rhein-MaasGebiet. Maastricht / Freiburg i. Br., 28-33.
Van Dierendonck, R.M., Swinkels, L.J.F., de Kind, R.E.L.B. &
J.H.A.C. de Mol, 1991. Roman Wall-Paintings in Northwestern Europe: Distribution and Context. Presentation and
preliminary results of a research project. In: Proceedings of the
4th International Colloquium on Roman Wall painting
(KölnerJahrbuchfürVor- und Frühgeschichte 24), 227-232.
Laken, L., 2007. Newly discovered large-scale figure paintings
from the Netherlands: the Roman villa at Kerkrade-Holzkuil.
In: C. GuiralPelegrín (ed.), Circulación de temas y
sistemasdecorativos en la pintura mural antigua. Actas del IX
Congreso Internacional de la Association Internationale pour la
PeintureMurale Antique [AIPMA], Zaragoza - Calatayud 2125 septiembre 2004, Zaragoza / Calatayud, 417-418.
Laken, L., 2010, “Romeins naakt uit Kerkrade. Wandschilderingen
uit de Romeinse villa van Kerkrade-Holzkuil”, PSHAL
(Publications de la Société Historique et Archéologique dans
leLimbourg) 146, 245-283.
Laken, L., J. de Mol& R. de Kind 2010, Roman wall-paintings
found in situ in Nijmegen! Reconsidering plaster finds from the
Netherlands, In: I. Bragantini (ed.), Atti del X congresso
internazionaledell’AIPMA (Association Internationale pour la
PeintureMurale Antique), Napoli 17-21 sett. 2007, vol. II,
Napoli, 531-546, Tav. LII 1-3.
Laken L., B.J.H. van Os & L. Megens. Fragmenten van beschilderd
pleisterwerk uit de Romeinse villa. In: Lauwerier, R.G.C.M.,
A. Müller, and D.E. Smal, eds. Merovingers in een villa. RAM
189. Amersfoort: Rijksdienst voor het Cultureel Erfgoed.
http://www.cultureelerfgoed.nl/sites/default/files/u4/RAMBorg
haren-Pasestraat.pdf.
Megens, L. et al. 2007, Painting materials in Roman wall-paintings
in the Netherlands, In: C. GuiralPelegrín (ed.), Circulación de
temas y sistemasdecorativos en la pintura mural antigua. Actas
del IX CongresoInternacional de la Association Internationale
pour la PeintureMurale Antique [AIPMA], Zaragoza Calatayud 21-25 septiembre 2004, Zaragoza / Calatayud, 501504.
Megens, L., 2008, Microscopisch en microchemisch onderzoek van
de verflagen (Bijlage XIV - deel 1), In: E. Blom & W.K. Vos
(red.), Woerden-Hoochwoert: De opgravingen 2002-2004 in
het Romeinse CastellumLaurium, de vicus en van het schip de
‘Woerden 7’ (ADC-Monografie 2, ADC Rapport 910),
Amersfoort, Bijlage XIV p. 1-3.
Megens, L., 2010, Pigmenten in de muurschilderingen, in: H. van
Enckevort& E.N.A. Heirbaut (red.), Opkomst en ondergang
van OppidumBatavorum, hoofdplaats van de Bataven.
Archeologischonderzoek op de St. Josephhof in Nijmegen 1,
Nijmegen (Archeologische Berichten Nijmegen, 16), 159-164.
45
Keep reading this paper — and 50 million others — with a free Academia account
Used by leading Academics
Rogelio Altez
Universidad de Sevilla
Estella Weiss-Krejci
Austrian Academy of Sciences
Viktória Kiss
Hungarian Academy of Sciences
Patrice GEORGES-ZIMMERMANN
INRAP, Institut National de Recherches Archéologiques Préventives
