Holocene sedimentary records of the Katarraktes cave system (northern Greece): a stratigraphical and environmental magnetism approach

The Katarraktes cave system is located in northern Greece and is a complex of a rockshelter and a cave formed on the south river bank of Krousovitis River canyon (Serres, Macedonia region). The archaeological site area is well known as one of the most important archaeological sites in SE Europe since it hosts numerous archaeological findings dating back to the Early Bronze Age. Detailed stratigraphic analysis of three archaeological sections was performed in order to define the depositional conditions of the cave entrance facies sediments. Mineral magnetic properties were performed to enhance the paleoenvironmental interpretations and to detect sediment origins. Magnetic susceptibility (klf) obtained in high and low frequency as well as remanence parameters, such as saturation isothermal remanent magnetization (SIRM) and S-ratio, were measured in samples collected2from the archaeological sections. Results indicate a significant variability in the magnetic signal stored in the sedimentary record of Kataraktes cave system distinguishing between natural and anthropogenic sequences. The combination of the stratigraphic and magnetic results along with the archaeological data reveals that flood events of Krousovitis River and sediment accumulation from slackwater in the rockshelter area occurred around 3000 yr BC and were possibly the key factor for the abandonment of the prehistoric settlement

Geoarchaeological study of Katarraktes cave system (Macedonia, Greece): isotopic evidence for environmental alterations

Archaeological excavations began in 2004 in the Katarraktes cave system, near Sidirokastro, Macedonia, Greece, and brought to the surface a great number of historical and prehistoric findings. Archaeological excavations concentrated on a rockshelter, with findings aged from Early Bronze Age. The main activity of that location seemed to be food preparation and storage. In order to investigate the correlation between human use of the cave and the environmental conditions of the area during those parts of prehistoric and historical time, an isotopic study was conducted dealing with the calcitic and organic deposits of a stalagmite from the cave. The analysis of the δ13C and δ18O isotopes in carbonate sediments provided information about the conditions at the time of precipitation of the carbonate material inside the cave. A succession of drier and wetter phases was highlighted, describing the unstable environment of the cave. A general reconstruction of the period of human occupation in the Katarraktes cave system was established, on the basis of a combination of the archaeological, geomorphological and isotopic data. The speleothem isotopic signatures indicate abrupt changes of the atmospheric conditions inside the cave, which are correlated to reported changes in rainfall during 3500-4500 BP in Mediterranean region.Des fouilles archéologiques ont débutées en 2004 dans la grotte de Katarraktes située à proximité de Sidiokastro en Macédoine (Grèce). Elles ont mis à jour un nombre important de trouvailles datant des périodes préhistorique et historique. Un abri sous roche et de nombreux artefacts datant du début de l’Age du Bronze ont été trouvés. Les principales activités liées à l’occupation du site semblent avoir été la préparation et le stockage de nourriture. Dans le but d’étudier les relations entre l’utilisation de cette grotte et l’évolution des conditions environnementales pendant les périodes préhistorique et historique, une étude isotopique a été menée sur des dépôts calciques et organiques provenant d’une stalagmite trouvée dans la grotte étudiée. L’analyse des rapports isotopiques δ13C et δ18O effectuée à partir des sédiments carbonatés a permis préciser les conditions environnementales qui prévalaient à l’époque de la précipitation des matériaux carbonatés à l’intérieur de la grotte. Une alternance de phases sèches et humides a été mise en évidence. Une reconstitution globale des données environnementales sur la période d’occupation humaine dans les grottes de Katarraktes a été réalisée en exploitant les données archéologiques, géomorphologiques et isotopiques. Les signatures isotopiques du spéléothème indiquent de rapides modifications des conditions atmosphériques et doivent être associés au changement climatique global survenu au cours Subboréal dans la région méditerranéenne entre 3500 et 4500 BP