calcareous matrix containing microfossils and silt size minerals derived from igneous and metamorphic rocks including flakes of mica, feldspar, plagioclase, olivine, etc. (Figs. 5.5, 5.6). Non-plastic material for most of the samples of this group constitutes about 5–7% of the volume of the sherds and is represented mostly by biogenic chalk with fine (0.1–0.2 mm) rounded to subrounded particles that was possibly added to the paste in the form of chalk powder. Other sand-size materials—pure brown clay nodules (up to 0.5 mm in diameter), grains of volcanic glass and forsterite (some particles of which are replaced by hetite)—are rare in the thin-sections. Firing temperature is estimated at close to 750ºC and
thin (~0.1 mm) surface vitrification is observed.