Cl PA 2003 XIX 11 ' International Symposium, 30 September - 04 October, 2003, Antalya, Turkey
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Figure 3. Patrimonial buildings and topographic prominences in downtown area Mexico City. There is a
clear relationship among cataloged buildings and the marks of the mounds produced by archaeological
remains.
concentration of recorded prominences. On most streets there
are major topographic knolls indicating the presence of big
structures. However, out of the old islet’s boundaries, there are
little topographic mounds on record, which suggests precisely
that the knolls constitute structures built within the territory of
the main islet.
The concentration of knolls proves the existence of pre-Hispanic
settlements. Nonetheless, the classification of the mounds,
alongside the geophysical results, allows for identifying a
settlement’s main structures. The second phase of the project is
now under way to study, using geophysical techniques, the
features of the located knolls. This part of the research project
resorts to topographic, magnetic, electric and radar equipment
determining the presence and the characteristics of the building
remains. Excavations and sounding drills constitute other study
techniques so to confirm hypothesis posited from the results of
the earlier stages.
At the Coyoacan zone experiments were carried out to prove
that geophysical high-resolution techniques are adequate to the
task of studying archaeological sites in urban contexts.
Topographic maps were made to carefully record the zone’s relief.
Over the surface of the Conchita square a magnetic gradient study
was undertaken which was able to overcome the interference
produced by the urban infrastructure. There is good concordance
between magnetic data and topographic knolls. A technique that
has given good results has been electrostatic resistance, which
without galvanic contact with the earth enables to obtain readings
on the pavement. This eased the study of most streets surrounding
the square producing a close correspondence between
topographic mounds and high electrostatic resistance values.
Preliminary results state that most mounds recorded are produced
by materials that modify the magnetic and electric properties of
the soil, also generating clear reflections of radar electromagnetic
waves. Georadar has discovered the approximate depth and shape
of accumulated collapsed materials that generate clear reflections
and affirm doubtless the existence of buried architectonic
remains.
