Pedogenic evidence sheds light on the post-Roman pedo-sedimentological and human history of Tarsus, the Roman capital of CE 60, Cilicia, Mersin, Türkiye

Abstract

The ancient city of Tarsus is underlying a sediment of 400 cm where the contemporary Tarsus grew. The diffusely stratified layers of the deposited sediment from the Kydnos (Tarsus) river overlying the Roman Road excavation site located in the heart of the modern city. The sediment is laden with technogenic materials. The profile of the stratigraphic layers represents a Pedocomplex (PDC) and its horizons are the Pedomembers (PDMs). All the PDMs were described and sampled for physical, chemical, mineralogical, micromorphological, and thermoluminescense analyses seeking pedogenic evidences. The origin of PDC materials is a fluvial and/or lagoon environment (archaeologically predicted date, about 60 CE, and they are calcareous, high in available P and some are high in total phosphorus contents). They have been partially modified by human activity in a settlement area, thus bringing some historical evidence suggesting that the site was part of the growing city after its abandonment. Thin sections show a vigorous biological degradation of the organic residues in the PDMs along with occasional evidence of soil-forming processes. The preliminary conclusions were extracted from the results obtained through the newly formed hydroxyapatite (Hap) determined by micromorphology, therefore proposing the new suffix π for the WRB soil naming system. Primary, high temperature and clay minerals together with TL analyses of the layers, were conducted to reveal the provenance and weathering phases of the horizons. The seeds recovered from an inhabited layer helped to interpret the food and medicinal habits of the local society and the contemporary presence of the lagoon.