Cl P A 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey
3. MAGNETIC EXAMINATION OF TWO SELECTED
AREAS AT THE SITE OF EMMAUS-NICOPOLIS
3.1 Methodology of field magnetic observations
The magnetic survey at the site of Emmaus-Nicopolis have
been carried out using following equipment:
• Proton Magnetometer MMP-203 (Era Assoc., Sankt-
Petersburg, Russia), No. 206033 (it was used for field
observations),
• Quantum Magnetometer MM-60 (Era Assoc., Sankt-
Petersburg, Russia), No. 207001 (it was used for
registering temporary magnetic variations at control
point),
• Kappameter K.T-5 (Scintrex, Canada) for magnetic
susceptibility measurements.
Results of archaeological excavations and brief geological
examination of the areas under study indicate that we have here
two types of geological associations: soil (0 - 1.5 m) and
underlying it limestone sometimes exposed at the earth’s
surface. A few tens performed measurements of magnetic
susceptibility indicate that limestone is practically non
magnetic, and soil is characterized by magnetic susceptibility of
60-100 x 10' 5 SI.
Detailed magnetic investigations were performed at two
conjugated areas A and B (Figure 3). Unfortunately, small part
of area A and significant part of area B have been not covered
by magnetic survey (see Figure 3) due to zone of very dense
vegetation (area A) and zone of rugged topography (area B).
Distance, m
Figure 3. Location of two investigated areas
Magnetic sensor level, according to experience of previous
works (Eppelbaum et al., 2000a, 2000b, 2003), was selected as
0.5 m above the earth’s surface. Temporary magnetic variations
were removed using conventional scheme (Telford et al., 1998).
Maps of the total magnetic fields over the areas A and B are
presented in Figures 4 and 5, respectively. Mean-square error
for magnetic observations at the area A was 1.85 nT and at the
area B - 0.9 nT.
The most important peculiarity of this survey is that from the
areas under study has been recently removed an upper part of
soil (two meter thickness) containing all modern contamination.
Thus, we can propose that three high-intensive anomalies
observed at the area A (see Figure 4) and significant anomaly
revealed at the area B (see Figure 5) are associated with the
buried ancient remains.
3.2 Quantitative interpretation of magnetic anomalies
This stage involves application of methods for quantitative
interpretation of magnetic anomalies for development of an
initial physical/archaeological model. The developed methods
Emmaus-Nicopolis
(improved modifications of characteristic point method and
tangent method are applicable in conditions of the rugged
terrain topography, arbitrary direction of magnetization of the
objects and unknown level of the normal magnetic field (Khesin
et al., 1996). For quantitative interpretation of magnetic
anomalies due to disturbing objects two geometric models were
utilized: thin bed (Figures 6, 8 and 9) and horizontal circular
cylinder (Figure 7). It should be noted that anomaly I (Figure 6)
has a form close to ideal of theoretical anomaly due to a thin
bed. By its interpreting was used so-called Reford’s point
(Reford and Sumner, 1964) showing a projection of the middle
of anomalous object to the earth’s surface. The disturbed upper
part of anomaly II was smoothly reconstructed (dash line in
Figure 7) for the more convenience interpretation. Anomaly III
is also disturbed by some nearly occurred magnetoactive
object(s). Anomaly IV of comparatively small intensity is
registered in the vicinity of the proposed continuation of
excavated underground tunnel. Determined depth of the upper
edge of the targets ranges from 0.7 to 1 m.
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