H. Calvo del Castillo, J.L. Ruvalcaba Sil, T. Calderón, M. Vander Meeren, L. Sotelo.
Introduction
The Grolier Codex is the last Maya document
discovered up to day. It was found in 1965 in
Chiapas (Mexico). Radio-carbon dating of one
its free standing sheets of paper, situated it in
1230 ± 170 AD matching the fall of the Maya
civilization when absorbed by the Totelcas.
However, specialists are not keen to accept its
authenticity as it bears unusual iconographical
content. PIXE and RBS studies have been
carried out in order to discard the presence of
modern materials within the preparation layer
and pigments.
The codex mistakes
Numeric system and the position of
numbers is not correct according to other
codex.
Anomalies in the content of the Venusian
calendar (Bad omen not related to Venus).
Support
inclination
SET-UP
120º
90º
60º
Beam
Horizontal
Proton Beam 3MeV
direction
Intensity current 1nA
Normal
Si (Peltier) 40º beam direction, He flux
LEGe 40º beam direction, 68µm Al absorber
RBS 45º beam direction
Preparation layer
PIXE reveals major elements such as Ca, O and
S for the preparation layer in concentration that
matches hydrated CaSO4. RBS did not detect
the presence of carbon, therefore carbonates
are considered to be absent.
0,7
0,6
0,5
0,4
50
0,3
0,2
40
0,1
K
20
Preparation Layer
Dark and Light areas
10
Red pigment
S(kα)
Ca(kβ)
Si(kα)
Al(kα)
O
S
Sr
Concentration % w-w ± 10%
Blue pigment
Fe(kα)
K(ka)
Fe(kβ)
100
Major elements in
prepraration layer
and blue paint
10
1,6
1,4
1,2
PIXE (Si-Peltier)
1
60
0,8
50
0,6
0,4
40
1
200
400
600
800
1000
Channel
RBS spectrum black
500
Carbon
400
Oxygen
300
200
Other
0
100
200
300
Channel
400
0
Fe
K
Mg
Al
Cu
500
Cl
Mn
Concentration
% w-w ± 10%
10
0
preparation layer
O
Ca
S
blue
Si
Sr
Blue Maya pigment is made of organic colorant indigo fixed on to a
paligorskite clay. RBS spectra showed the presence of carbon
perhaps indicating the presence of some organic substance. PIXE
spectra threw composition of some kind of clay. However it is not
possible to assure the use of Blue Maya with these techniques and
further analyses ought to be made for its characterization.
Black pigment
100
0,2
30
20
The large amount of iron in the red areas
together with elements present in soil is
characteristic of impure red ochre: Fe2O3 +
clay elements.
Intensity (counts)
intensty (a.u.)
1000
dark
light
0
Ca
Ca(kα)
dark
light
Fe
Page 5 minor elements
0
30
600
RBS revealed the
presence
of
carbon in the
black pigments,
thus
indicating
the presence of
carbon black.
Acknowledgements
Authors would like to thank technicians K. López and F. Jaimes for their
support at the Pelletron particle accelerator during measurements.
Financial support was by projects MEC MAT2002-180, UNAM-DGAPAPAPIIT IN 403302. UNAM-DGAPA-PAPIIT IN 16903, CYTED
Proy.VIII.12.