engleski

Weathering of Bronze Age potsherds in a Mediterranean climate (Cres Island, Croatia)

The aim of this study was to study the causes of well preserved status of potsherds in bronze age hill forts on Cres island (Northern Adriatic Sea) exposed to Mediterranean climate and their buried equivalents in colluvial deposits. The island of Cres has a long history of settlement and hosts some very important Mesolithic, Neolithic and Bronze age sites. Due to erosion large areas are bare karst lacking soil cover and prehistoric potsherds can be found in stonewalls of hill forts or caves. The potsherds were analyzed by microscopy methods as well as geochemistry to study the weathering process in both exposed and buried potsherds. The colluvial soil containing potsherds was dated at Beta Analytic AMS facility ( Beta-199264) and a calibrated 14C date ranging from 2030 to 1870 BC was obtained. Under the optical microscope, the potsherds are texturally homogeneous and display inclusions of similar type, abundance, and grain size. The enrichment of Ca in exposed potsherd rims is accompanied by depletion of light REE’ s and enrichment of heavy REE’ s. The results show that potsherds exposed to the Mediterranean climate for four thousand years have an improved durability due to calcite re-crystallization and notable change in the chemical composition of potsherd rims which have to be considered when using bulk geochemistry for provenance studies.

geochemistry; weathering; potsherds; Cres; Bronze Age

Geochemica et Cosmochimca Acta ; Issue 15 Supplement 1 ; ISSN 0016-7037