Characterization of Clay Deposits in the Ceyhan Plain (Eastern Cilicia, Turkey): Integrated Petrographic, Mineralogical, Geochemical, and Geospatial Analysis for Provenance Studies of Ancient Ceramics

Abstract

This study presents the results of a comprehensive multi-analytical investigations of clay deposits from the Ceyhan Plain in Eastern Cilicia, Southern Turkey, aimed at establishing a robust framework for provenance studies of ancient ceramics in the region. A total of 52 clay samples were systematically collected and analyzed using optical microscopy for petrography (OM), X-Ray powder diffraction for mineral phase analysis (XRPD), laser ablation inductively coupled plasma mass spectrometry for geochemical (LA-ICP-MS), and geographic information systems for Geospatial Analysis (GIS) to examine the compositional characteristics and define reference clay groups for archaeometric research. Briquette samples were prepared from the collected clay to facilitate direct geochemical and petrographic comparisons with archaeological ceramics and clay-based artifacts. The results demonstrate that the clay deposits are predominantly calcareous, with contribution from mafic rocks and minor input from ultramafic sources. The compositional diversity is primarily shaped by sedimentation processes associated with the Ceyhan River, while smaller drainage systems influence localized variations. Four distinct clay reference groups were identified: the Ceyhan River Clay Group, Imamoglu-Kozan Clay Group, Kadirli-Savrun Clay group, and Osmaniye-Iliksu Clay Group. These groups serve as reference materials for comparative studies of ancient ceramics enabling deeper insights into local ceramic production strategies and exchange networks within the Eastern Cilicia Plain and its surroundings. They also serve as essential materials for provenance analyses of ceramics and other clay-based artifacts in broader regional contexts, including the Mediterranean, Anatolia, and the Levant. The study further underscores the importance of a multidisciplinary approach and the integration of excavation data with landscape and systematic raw material analysis to achieve a more nuanced understanding of ancient production strategies and resource management.