Explaining Dark Earth’s formation processes may help to understand the settlement strategy

• Multilayered occupational deposits originated in wet alluvial plain environment. • The site was protected against the humidity by layers of pure sand. • Organic dark horizons have high variability and represent different phases of occupation. • The entire suite of deposits can be classified as Dark Earth, specifically as Endo-stagni arenic Technosols. This study focuses on the geoarchaeological analysis of occupation deposits preserved at the edge of the early medieval site of Mikulčice, the centre of the Great Moravian proto-state (8th–10th century CE). The combination of soil geochemistry, grain size analyses and micromorphological observations applied to two sections and linked with wider sedimentological and archaeological context were applied to complicated archaeological structures. From the given data is obvious, that settling in this area was strongly influenced by the presence of increased underground water, so repeated terrain levelling with permeable sands was the necessary maintenance, followed by the deposition of sediments enriched by human waste, alongside episodes of soils formation. These sedimentary deposits condition were one of the most important factors for the formation of Dark Earth, driven by biological mixing of kitchen waste, charcoal, bone fragments, and excrements. The study presents one of the first descriptions of Dark Earth in Czechia outside a high medieval urban context, specifically identifying it as Endo-stagnic Arenic Technosols at an early medieval hillfort.