Of Fire and Water Microarchaeological Evidence of Mining, Rituals and Floods in North Tyrol's Kropfsberg Mine (Austria)

Abstract

Kropfsberg, located near Reith im Alpbachtal, in North Tyrol (Austria), has been exploited for its copper ores for centuries, since at least the Early Iron Age. Excavations conducted in 2020 by the University of Innsbruck exposed the detailed stratigraphic sequence of the mine, leading to a surprising discovery: what was initially believed to be only a site for mineral extraction showed clear indications of ritual use during the Roman period and Late Antiquity. These cultic layers are characterised by abundant charcoals, animal bones and almost 200 votive coins, and suggest that the mine served during this period as a Mithraeum. Using micromorphology and µXRF, along with macroscopic, hydro- and geomorphological information about the mine and its surroundings, we reconstructed the processes that led to the deposition of sediments within this artificial cave. Our analyses indicate that remains of ceremonial fires and offerings were deposited within a cultic pit, rather than being spread over the floor. Also, evidence suggests that the cultic use of the mine likely ceased before the area surrounding the mine was flooded, potentially due to the damming of the Inn River caused by a significant rock fall during the Roman period. We also traced the phases following the inundation, including the cave's reopening after a period of abandonment, and identified a sequence of mining backfills that provide evidence of the site's subsequent secular use. Ultimately, the study sheds new light on the cultural and geomorphological dynamics of the Inn Valley during the Roman Period and the Late Antiquity, while underscoring the importance of integrating microarchaeological approaches to disentangle the complex interaction of cultural and environmental influences, even in historical (artificial) cave contexts.