MÖSSBAUER STUDY OF FIRING CONDITIONS USED IN THE MANUFACTURE OF THE GREY AND RED WARE OF TURENG-TEPE

Abstract

Ancient potsherds, paleo-sols, and modern soil samples from the Gorgan plain of Northeastern Iran have been characterised by Mossbauer spectroscopy, X-ray diffraction, elemental and mineralogical analysis. The clay and other mineral species, and especially the iron-bearing minerals in the soils were identified, Test firings were carried out in the temperature range 650- 1 150 OC in air or in a reducing atmosphere. The quadrupole splittings of the ferric and ferrous doublets are functions of the firing tempera- ture, and thus the temperature used by the ancient potters, can be estimated. Sherds of the red and grey ware from Tureng Tepe IIA (3 000-2 800 B. C.) were examined, and respectively found to be oxidized or reduced compared with the soils. Firing temperatures of (1 050 50) OC and (980 f 50) OC were deduced for samples of the two types of pottery thus the grey ware could be fired at a temperature of 50 to 100 OC lower than the red ware.