Chemical Analysis of Floors in La Casa de las Aguilas, Templo
Mayor, Using NITON pXRF and Spot Tests Claudia Brackett, Richard
Lundin, Luis Barba, Agustin Ortiz, and Martin Terreros Slide 2 This
PowerPoint has been modified from its original presentation format
to make easier to understand by a single viewer without narration
by an oral presenter Slide 3 The study site is located in the Aztec
City of Tenochtitlan and is presently in downtown Mexico City Slide
4 The study site, The House of the Eagles, is located to the north
of Templo Mayor Slide 5 Samples were collected with a masonry
drill. Samples were bagged and taken to the laboratory for
analysis. Slide 6 The samples were treated to chemical spot tests
for protein, carbohydrates, fatty acids, pH, and phosphorous The
samples were treated to chemical spot tests for protein,
carbohydrates, fatty acids, pH, and phosphorous. Slide 7 Then the
samples were analyzed for up to 22 elements by portable X-ray
fluorescence Slide 8 Do not try to read all this data. Just
understand the wealth of information that we had to choose from. 22
elements times all of the sample sites gave us a lot to work with.
Slide 9 We decided to focus attention on elements that complemented
the results of the chemical spot tests Slide 10 First, the raw
numbers were graphed so that trends could be determined. Relevant
elements were selected for further analysis and mapping. Slide 11
This is the floor plan for the House of the Eagles. Numbers
indicate sample locations. The chemical spot tests were done for
all of these samples. Slide 12 pXRF analysis of the elements was
done only for samples taken from the inner room. Slide 13 The pXRF
data will be displayed on this schematic of the inner room. Slide
14 Statuary was found at the site. Their locations are indicated
here. Slide 15 The results of the chemical tests suggested use
areas Slide 16 High pH (dark red) is associated with ash. Slide 17
Here ashes are associated with the braziers. High values are in
portico area, while the lower values are in the central room.
Higher pH values occur in areas surrounding the main altar. The
highest values are around the braziers in the north doorway and the
corners of the pillars. X X X X Slide 18 Potassium, (K), is also
associated with wood fires. The pXRF distribution in the inner room
indicated a fairly even distribution of K Slide 19 Potassium
distribution is reasonably consistent with pH thus supporting the
assignment of ash. Slide 20 Phosphorous can be an indication of
organic tissue deposition. Phosphorous enrichment has been
associated with food preparation and burials. Possible sources of
phosphorous are nucleic acid and the phospho-lipid cell membrane.
Phosphorous could also be expected from blood deposition. Slide 21
High levels of phosphorous were in the portico while low values
were in the open patio. Important concentrations can be observed
close to the altars and braziers. Phosphorous values increase in
the doorways between the sculptures. Slide 22 Protein, specifically
albumin was assayed. Protein suggests the presence of blood. Slide
23 The highest values of protein were in the portico while the
inner rooms were clean. Slide 24 Protein was present where
Mictlantecuhtli with flesh statues were placed on both sides of the
north doorway Slide 25 This can be explained by the reported
practice of pouring blood on the sculptures head Slide 26 Protein
was also present in the middle of the doorway where eagle-dressed
men figures were placed. Also, high concentrations of protein were
found in front of the skeletal Mictlantecuhtli suggesting a self
sacrifice Slide 27 Iron from hemoglobin would be associated with
blood. It could also be a pigment used in wall decorations Slide 28
The pXRF analyzed distribution of iron showed definite activity
areas Slide 29 To further confirm the presence of blood deposition,
we would like all of the chemical evidence to be consistent. Blood
contains albumin protein, iron from hemoglobin, and phosphorous
from cell membranes. If the concentration patterns coincide it
further corroborates the presence of blood. Slide 30 It was found
that the concentration patterns of protein, iron, and phosphorus
did correspond in two areas of the room. This is shown on the next
slide. Slide 31 Phosphorous IronProtein Slide 32 The results of
phosphorous, iron and protein chemistry all indicate the deposition
of blood. Slide 33 Iron could also be explained as coming from
paint or decorative pigments. In this case we wanted to establish a
negative coorelation between iron and copper. Slide 34 Copper is an
important ingredient for certain blue and green pigments. Its
distribution could indicate decorative features. Copper was plotted
to contrast with iron distribution. Slide 35 Copper distribution is
concentrated near walls Slide 36 Copper distribution patterns are
dissimilar to iron except along one wall. Slide 37 Fatty acids are
associated with animal fats and tissue. Such fatty acids could be
deposited around braziers where offerings were burnt. Fatty acids
can also be found in the tree resins used to make copal. Copal was
most frequently burnt as an incense, but could also be used as a
paint binder. Fatty acids can also be found in the tree resins used
to make copal. Copal was most frequently burnt as an incense, but
could also be used as a paint binder. Slide 38 Fatty acid
depositions were found near braziers and in front of altars. Slide
39 Gas Chromatography has identified high molecular weight fatty
acids that suggests copal resins in front of the main altar. Slide
40 Conclusions Chemical analysis was useful in determining
different activity areas of the House of the Eagles. Examples are
as follows. Slide 41 Conclusions The location of braziers and
ritual fires.The location of braziers and ritual fires. The use of
copal at the main altar.The use of copal at the main altar. The
pouring of blood on the Mictlantecuhtli with flesh sculpture, but
not the other sculptures.The pouring of blood on the
Mictlantecuhtli with flesh sculpture, but not the other sculptures.
The practice of self sacrifice near the inner door sculptures.The
practice of self sacrifice near the inner door sculptures. Slide 42
Thanks To Thermo Fisher Scientific NITON Analyzers.Thermo Fisher
Scientific NITON Analyzers. Universidad Nacional Autnoma de Mxico
(UNAM)Universidad Nacional Autnoma de Mxico (UNAM) California State
University StanislausCalifornia State University Stanislaus
