Philpotts, A. R. (1994). Application of petrofabric and phase equilibria analysis to the study of a potsherd. J Archaeol Sci 21 (5). Vol 21(5), pp. 607-618.
 Title The title of the publication or report |
Application of petrofabric and phase equilibria analysis to the study of a potsherd | ||||||||
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Issue The name of the volume or issue |
J Archaeol Sci 21 (5) | ||||||||
Series The series the publication or report is included in |
Journal of Archaeological Science | ||||||||
Volume Volume number and part |
21 (5) | ||||||||
Page Start/End The start and end page numbers. |
607 - 618 | ||||||||
Biblio Note This is a Bibliographic record only. |
Please note that this is a bibliographic record only, as originally entered into the BIAB database. The ADS have no files for download, and unfortunately cannot advise further on where to access hard copy or digital versions. | ||||||||
Publication Type The type of publication - report, monograph, journal article or chapter from a book |
Journal | ||||||||
Abstract The abstract describing the content of the publication or report |
This paper describes how two standard materials analysis techniques using a petrographic microscope and x-ray diffractometer can be used to determine the fabrication method and firing temperature of a ceramic vessel even when only a small sherd is available. The amount clay is deformed during construction of a vessel depends on the fabrication method. Use of the coiling technique, for example, would involve more deformation than the slab method. The amount of stretching can be calculated from the degree of preferred orientation of elongate pieces of temper in the ceramic, as measured in a thin section cut through the sherd. The method was applied to an example from the USA tempered with shell, quartz and grass. The shell had completely dissolved away and the grass had burned during firing, to leave elongate cavities in the ceramic. The quartz grains, which are also elongate, are interpreted to be knapping debitage. The maximum degree of stretching calculated from the preferred orientation of this temper is only 2.3, which indicates that the vessel was fabricated from slabs rather than from coils. An x-ray image of a large part of the reconstructed vessel confirms the presence of these slabs, which are about 10cm long and range in height from 2 to 5cm. This image also indicates that the slabs were added in a counter-clockwise direction, which suggests manufacture by a right-handed potter. Although the surface of the vessel is tan coloured, most of the ceramic is black due to the reduced state of iron in the interior of the vessel. Burning of the grass temper during firing produced reducing conditions in the interior of the vessel wall that allowed wüstite (FexO) to form along with magnetite (Fe3O4). The unit cell dimension of the wüstite, measured by x-ray diffraction, indicates a composition that can only coexist with magnetite at 880ºC. This is believed to be the maximum temperature reached during firing of the vessel. The black, reduced ceramic is not wetted by water, whereas the red oxidised surface material is. The grass temper, which produced the reduced ceramic may therefore have been added to the clay to make a more impervious vessel. | ||||||||
Year of Publication The year the book, article or report was published |
1994 | ||||||||
Locations Any locations covered by the publication or report. This is not the place the book or report was published. |
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Source Where the record has come from or which dataset it was orginally included in. |
BIAB
(The British Archaeological Bibliography (BAB))
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Created Date The date the record of the pubication was first entered |
20 Jan 2002 |
