Red Calcium Phosphate-covered Phytoliths from the Soil of the Bronze Age Tell Settlement of Százhalombatta-Földvár, Hungary

Abstract The tell settlement of Százhalombatta-Földvár in Hungary was inhabited from approximately 2000 to 1400 BC. Archaeological excavations have been carried out annually for over 25 years as part of the “Százhalombatta Archaeological Expedition (SAX)” project. As it is a long-lived Bronze Age settlement, the finds consist primarily of remains of houses and pits, as well as refuse and soil deposits. During the 2024 archaeological excavation campaign in Százhalombatta-Földvár, unusual reddish deposits were discovered on the bottom of a pit. These were partially associated with phytoliths. SEM-EDX analyses revealed that the reddish substance is Ca 3 (PO 4 ) 2 , deposited in layers on top of phytoliths. Reflections on the origin of these deposits led to the conclusion that this could only have occurred due to several favorable conditions: the formation of phytolith layers, lime in the soil, water with dissolved Ca 2 ⁺, and the gradual introduction of phosphate. Perhaps further evidence of the phosphate source will be found in future excavation campaigns in the vicinity of the site.