Archaeometric analysis of an early copper dagger from Kozareva Mogila, Western Black Sea region

Abstract

In the fifth millennium BC (the Eneolithic period), copper extractive metallurgy developed in the region of Thrace and the Lower Danube. Massive tools and weapons were produced from copper. At the end of the fifth millennium, this development stopped, and the cultures associated with it disappeared. A period of cultural transformation followed, as a result of which the Early Bronze Age cultures appeared, which developed a different type of metallurgy, beginning with the so-called arsenic bronze. This transitional period lasted several hundred years. There is relatively little information on it, particularly for the region of Thrace. The reason for this is that after the end of the third phase of the Late Eneolithic Kodjadermen-Gumelniţa-Karanovo VI culture, a hiatus usually follows in the settlement mounds, above which the Early Bronze Age layers follow. In Kozareva Mogila, a separate layer of phase IV of the culture was discovered for the first time in a settlement mound. It represents the end of the Eneolithic and the beginning of the transitional period to the Bronze Age. This continuity in cultural development indicates that the old population was preserved. Here, we present a copper dagger from the site, originating from this layer, in which only materials from phase IV of the Late Eneolithic are present. A sample from the dagger was studied at the ‘Curt-Engelhorn’ Zentrum für Archäometrie, Mannheim, Germany. An XRF analysis was conducted to determine the chemical composition, and a lead isotope analysis was done to determine possible sources of raw material. The provenance study allowed the dagger to be related to some of the copper deposits in the Strandzha area. The XRF analysis showed that the artefact is made of copper with 0.54 % As, which is probably due to the deliberate use of copper ores with naturally occurring arsenic.