In the course of a study of pottery from Celtic Central Europe, we report on an investigation of pottery found in the context of a Celtic ditched square enclosure near the modern town of Bopfingen in Baden-Wurttemberg, Germany. The studied pottery may be visually subdivided into wheel-turned ware, graphite ware, and coarse ware. The Mossbauer spectra are surprisingly uniform, indicating that all types of pottery were fired in a similar manner. Firing in a reducing environment at 800 degrees C was usually followed by re-oxidation during cooling, which leads to unique features in the low temperature Mossbauer patterns.
We present an overview on an extended study of Celtic ceramics from the oppidum of Manching and from some contemporary Celtic sites. The results of neutron activation analysis, thin section microscopy and Mössbauer spectroscopy are combined with the existing detailed archaeological typology to provide information on the provenance of Celtic pottery and on details of its production. The data indicate that there was only very limited exchange of material but far reaching transfer of technology.
In 1995 a well preserved 3rd century BC Celtic kiln for pottery making was excavated at Schmiedorf in Lower Bavaria. The firing chamber and the flue plate of the kiln were preserved, whereas the dome was not found. We report on a study of material from this kiln by neutron activation analysis, thin-section microscopy, X-ray diffraction and Mössbauer spectroscopy, all performed with the aim to learn more about pottery-making procedures in Celtic times.
For the characterization of archaeological ceramics, the study of thin sections under the polarizing microscope is a very efficient analytical technique. There are two properties of ceramics which can be analysed by thin sections, namely the mineralogical composition and the fabric. Both features show a considerable variety which permits a very detailed description of ceramic wares. With respect to the mineralogical composition, there is a wide variety of rock forming minerals, of heavy and ore minerals, fragments of stone, fossils, organic inclusions like straw or pieces of charcoal as well as artificial inclusions like slag or crushed pottery, which define with the temper of the pottery in much detail. The fabric also shows considerable differences in grain size, in the amount of temper, in the orientation of grains and other features, which provide further quantitative data on the properties of archaeological ceramics. From this information, the material can be well characterised, and conclusions as to the region of origin and the potter's techniques can often be drawn.
Sicán blackware from a 1000-year old elite tomb at Huaca Loro was characterised by neutron activation analysis, optical thin-section microscopy, X-ray diffraction and Mössbauer spectroscopy. A number of blackware fragments from the later site of Puerto Pobre (ca. AD 1460–1550) were included in the analysis for comparison and found to be of different origin. The black surface of the specimens from Huaca Loro is mostly due to carbon deposition during firing in a reducing environment. Part of the pottery was merely dried at temperatures below 400°C, perhaps because it was made in haste for funeral use.
Ceramic finds from the Galería de las Ofrendas at Chavín de Huántar and surface finds from the settlement of Chavín were characterised by combining the results of archaeological typology with archaeometric studies using neutron activation analysis, Mössbauer spectroscopy, X-ray diffraction and thin-section microscopy. Sherds from the pyramid Tello are included in the study as representative of local material. The analyses show that the vessels were made from different raw materials and that different firing procedures were used in their production. Sherds of certain styles largely exhibit similar types of Mössbauer patterns and in many instances also have similar element compositions. This supports the archaeological notion that the vessels were brought to Chavín from the provinces, perhaps on the occasion of a festivity.
Material from field firing experiments using a 2,700-year old Formative kiln at Batán Grande, Peru, was studied by X-ray diffraction and Mössbauer spectroscopy. The experiments explore the technology involved in producing the gray and black reduced ware for which Cupisnique and other Formative ceramics are justly known. During firing, the iron-bearing compounds in clays undergo characteristic changes which depend on kiln temperature and atmosphere. These changes can be observed in the Mössbauer spectra. By comparing spectra of an appropriate clay fired in field experiments and in the laboratory with the spectra of ancient ceramics, a description of Formative firing techniques in a reducing environment is attempted.
Early techniques of making pottery can be investigated by 57 Fe Mössbauer spectroscopy. Iron is generally present in unpurified clays in concentrations of several percent. During firing, the iron undergoes characteristic changes of its chemical and physical state, depending on the kiln atmosphere and on the maximum firing temperature reached. These changes can be followed by Mössbauer spectroscopy. Firing techniques can often be reconstructed when spectra of laboratory and field fired samples are compared with those observed in ancient sherds.
The potential of Mössbauer spectroscopy in the reconstruction of production techniques of early ceramics is demonstrated by the results of a study of a Formative kiln site at the Archaeological Park at Batán Grande, Perú, and of ceramics from the nearby settlement of Huaca Chólope.
Following new discoveries in 1985, research has been conducted into the high artistic- and technological quality-ceramics produced by workshops and kilns dating to the Formative era (ca. 1800-500 BCE) in the Peruvian Andes. This chapter compares data from the test firing of a Cupisnique kiln at the excavation site with technical analyses of associated ceramics and laboratory firing experiments. Contents: 1) archaeological aspects: historical discussion, description of the kilns, test firings of the kilns; 2) materials 3) methods and results: neutron activation analysis, x-ray diffraction and thin-section microscopy, Mossbauer spectroscopy, clay from Batan Grande, laboratory firing of the clays; assessment of the firing conditions, color determination; 4) conclusions.
A Mössbauer typology of 120 early phoenician ceramic sherds from Kāmid El-Lōz, Lebanon, is proposed. It is found to agree well with other classifications by means of neutron activation analysis and thin section microscopy. Two ancient calcium rich clays and one recent calcium poor clay from the same region were fired in the laboratory in oxidizing and reducing atmospheres at temperatures increasing stepwise from 50 °C to 1200°C, with Mössbauer spectra taken at room temperature and occasionally at 4.2 K. These model experiments were undertaken with the aim to reconstruct the firing techniques of the early phoenician potters. The firing temperature of the locally made pottery appears to have been low.
A large number of ceramic sherds from Chavin, Peru, as well as recent clay samples from the same region have been studied by Mössbauer spectroscopy. The changes of the Mössbauer spectra of the clay were studied as a function of firing temperature and atmosphere. From a comparison of these data with those form the sherds one can make estimates of the precolumbian firing conditions.
To obtain information on the firing of inca ceramics, 7 samples from different locations were studied by Mössbauer spectroscopy including a detailed laboratory refiring procedure. The glaze typical for the surface of this ware was studied by Mössbauer scattering.