In collaboration with M. J. Blackman, an ongoing program of chemical analysis of Gordion pottery and local clay samples is being carried out by instrumental neutron activation analysis (INAA) in the Smithsonian Center for Materials Research and Education facility, using the 20 MW NBS Research Reactor at the National Institute of Standards and Technology. The analytical protocol is a modification of that outlined by Blackman (1984). Williams et al. (1987) had previously compared the pastes of local Hellenistic grey ware pottery with that of imported Hellenistic Black Glazed ware using PIXE [Proton-Induced X-ray Emission] analysis.

The current program is providing data on both the nature and possible extent of local production at Gordion and the changing patterns of local resource exploitation.

Pottery Samples

Limited sampling of minor wares (e.g., Buff Fine and Cooking wares in the Late Bronze Age and finer grey and buff wares in Phrygian periods) has begun exploring the variability among wares within single periods.

In two cases it has been possible to sample individual vessels, representing most contemporary ware and vessel types, from very tightly dated and stratigraphically discrete deposits:

Samples from architectural terracottas, particularly 29 tiles from the roof of one Hellenistic building (Galatian phase, YHSS 3A), have also been run (Henrickson and Blackman 1999; see Hellenistic Tile Roof).

All ceramic samples were prepared by grinding away all surfaces and edges before crushing to a fine powder in a mortar. Samples of 100±5 mg were packaged for activation.

Clays from both ancient and modern deposits were sampled to define the nature of clay resources available and to determine whether changes might have occurred over time. Samples come from two sources: natural deposits surrounding Gordion and massive clay construction fills on the Citadel Mound. Shrinkage and workability tests confirmed that almost all of the clays sampled were potentially usable for pottery production, even without preparation (see also Johnston 1970). At present, only clays from the Sakarya River drainage have been sampled; two other nearby streams (the Ankara and Porsuk Çay) remain untested.
 

Clay fill layer in Operation 2 (above stone wall and below stone pavement in baulk).

These clay samples from fills provide critical data on potential 'local' raw materials, available near the settlement, during the Phrygian florescence in the second quarter of the first millennium BC.

Clay Sample Preparation. Preparation and firing temperature have crucial effects on the long-term durability of a ceramic fabric made using calcareous clays. Decomposition of calcium carbonate (CaCO3: limestone, calcite, or shell) into lime (CaO) occurs over a range of temperature, beginning at ±800 C and accelerating at 870-900 C; its pace depends on grain size, purity, and the partial pressure of CO2. Rehydration of the lime causes expansion, producing cracking, spalling, or disintegration of the ceramic fabric. In order to improve comparability between the clay samples and ceramics, two unaltered lumps (1-2 cm in diameter) of each clay sample were fired for one hour at 650 C and 850 C in an oxidizing atmosphere. These bracket the temperature at which carbonate decomposition occurs and represent the range of original firing temperatures for common wares as estimated from refiring experiments.

Blackman, M. James

1984 "Provenance Studies of Middle Eastern Obsidian from Sites in Highland Iran." In Archaeological Chemistry, pp. 19-50, edited by J. Lambert. American Chemical Society.

Henrickson, Robert C., and Blackman, M. James.

1996 "Large-Scale Production of Pottery at Gordion: A Comparison of the Late Bronze and Early Phrygian Industries" Paleorient 22(1): 67-87.

1999 "Hellenistic Production of Terracotta Roof Tiles Among the Ceramic Industries at Gordion". Oxford Journal of Archaeology 18(3): 307-326.

In prep. "The Early Iron Age Pottery Industries at Gordion: A Technological and Compositional Investigation of Interrelationships". To be submitted to Journal of Mediterranean Archaeology.

In prep. "Pots, Pastes, and Production Methods: Continuity and Change between the Early and Middle Phrygian Pottery Industries at Gordion."

Henrickson, Robert C., and Voigt, Mary M.
1998 "The Early Iron Age at Gordion: The Yassihöyük Stratigraphic Sequence." Pp. 79-107 in Thracians and Phrygians: Problems of Parallelism (Proceedings of an International Symposium on the Archaeology, History, and Ancient Languages of Thrace and Phrygia [Middle East Technical University, Ankara, Turkey, 2-6 June 1995]), edited by Numan Tuna, Zeynep Aktüre, and Maggie Lynch. Centre for the Research and Assessment of the Historic Environment. Ankara: Middle Eastern Technical University (METU), Faculty of Architecture Press.

Johnston, Robert H.

1970 Pottery Practices During the 6th-8th Centuries B.C. at Gordion in Central Anatolia: An Analytical and Synthesizing Study.Ph. D. dissertation, Pennsylvania State University.

Voigt, Mary M.; DeVries, K.; Henrickson, R. C.; Lawall, M.; Marsh, D.; Gürsan-Salzman, A.; and Young, T. C.,Jr.

1997 "Fieldwork at Gordion: 1993-1995." Anatolica (Annuaire international pour les Civilisations de l'Asie Antérieure) 23: 1-59.

Voigt, Mary M., and Henrickson, Robert C.

In press "The Early Iron Age at Gordion." To be published in Peoples of the Sea, edited by E. Oren and L. Bregstein. University Museum Monograph. Philadephia: University of Pennsylvania Museum of Archaeology and Anthropology.

In press "Gordion -- The Formation of the Phrygian State" To be published in Anatolian Studies 50 (2000).

Williams, E. T.; Cadet, G.; Guardala, N. A.; Huang, E; and Winter, F. A.

1987 "Analysis of Pottery by PIXE: Late Classical and Hellenistic Imports to Gordion. Nuclear Instruments and Methods in Physics Research B22: 430-432.

© 2000 R. C. Henrickson