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| Titel |
Combined archaeomagnetic and thermoluminescence dating of a kiln excavated at Fontanetto Po (Northern Italy) |
| VerfasserIn |
Evdokia Tema, Fulvio Fantino, Enzo Ferrara, Alessandro Lo Giudice, Federico Barello, Moira Bertasa |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250050584
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| Zusammenfassung |
| Combined archaeomagnetic and thermoluminescence study was carried out as part of an
archaeological rescue operation on a kiln discovered during the installation of methane tubes
beneath a rice field, along the southern border of Fontanetto Po (Northern Italy).
Hierarchical sampling process has been followed collecting 23 independent brick
samples oriented in situ using an inclinometer. The presence of the metallic tubes in a
depth around 1 m below the structure, and the bad weather conditions, prevented
the use of magnetic compass and the sun orientation of the samples, respectively.
Investigation of the isothermal remanent magnetization points to Ti-magnetite as the main
magnetic carrier, while in some samples a high coercivity mineral, most probably
hematite, is also present. Hysteresis cycles obtained for representative samples
after heat-treatments up to 800 Ë C indicate that the bricks have been baked at
temperatures around 500 to 700o C, depending on their position in the kiln. Stepwise
thermal and AF demagnetization shows no or negligible secondary magnetization
components and a very stable characteristic remanent magnetization (ChRM). The
calculated mean inclination of the 23 samples is I = 64.9o with α95= 2.4o and k = 150.
The archaeomagnetic age of the kiln has been obtained after comparison of the
kiln’s archaeomagnetic inclination with both, the Italian reference secular variation
curve, and the reference curve produced by the SHA.DIF.3K European regional
geomagnetic field model. Two possible dating intervals result for the last 1000
years calculated at 95 % confidence interval: a first from 1461 to 1604 AD and a
second one from 1779 to 1876 AD. In addition, thermoluminescence study has been
performed on three samples, using conventional laboratory procedures. Although
consistently affected by the relevant water content of the site, the archaeological and
annual dose of the samples have been estimated and used to calculate the kiln’s age.
According to the thermoluminescence results the kiln has been used for last time
between 1650 and 1800 AD, but further assessment of the environmental dose
is required to restrict this dating interval. This result is in good agreement with
the second dating interval obtained by the archaeomagnetic results and suggests
that the last firing of the kiln could have occurred as late as the 18th century AD. |
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