DISTINCT MINERALOGY AND FABRIC OF EARLY MEDIEVAL AND HELLENISTIC POTTERY, GREVENA, NORTHWEST GREECE

More than 300 archaeological sites have been identified by Grevena Project, an all-period archaeological survey of the 2500 square km prefecture of Grevena, southwest Macedonia, Greece. These archaeological sites were variously inhabited at periods ranging from Early Neolithic (circa last half of 8^th millennium B.C.) to Ottoman (15^th to early 20^th century A.D.). Whereas sites of some ages are confined to particular areas within the prefecture, sites of Hellenistic (late 4^th to late 1^st centuries B.C.) and Early Medieval age (7^th to 10^th centuries A.D.) are spread across the entire area. In this petrographic study, we compared the composition and texture of 27 pottery sherds, most from cooking pots and storage vessels, 14 of Early Medieval age and 13 of Hellenistic age, counting at least 300 points (including at least 100 inclusions) per slide. Results illuminate possible differences in methods used to create the pottery, ranging from how long the clay was kneaded before firing, the use of varying types and amounts of temper, and variations in firing temperature. For instance, compared to Hellenistic pottery, the fabric of the Early Medieval sherds contain more void spaces and therefore seem to been less worked (kneaded). These sherds also have a larger quantity of natural temper (derived from the main of sediments used to make the pots) rather than manually-added temper, such as grog (derived by breaking up older pots). However, grog is also a component in several of the Early Medieval sherds. Pottery derived from local sources can be identified a) by components unique to the local geology, such as olivine, pyroxene and rock fragments from exposed ophiolite sequences; b) by poor sorting of non-matrix inclusions; and c) by overall higher percentages of inclusions. Using these criteria, we conclude that several, perhaps all of the Early Medieval sherds could have used local soils. Hellenistic-aged sherds vary considerably more in matrix percent, type of temper, distribution of inclusion sizes and holes, and other properties. Some of these Hellenistic sherds may have been imported. These petrographic trends are consistent with historical information that connects Hellenistic Grevena to an Eastern Mediterranean civilization, whereas cultural ties in Early Medieval Grevena were mainly confined to the Balkans.