New geoarchaeological investigations of the valley systems in the Aksum area of northern Ethiopia

Recent geoarchaeological investigations of the valley systems to the north and northeast of Aksum have revealed indications of a relatively recent alluvial sequence, probably within the last millennium. The implication is that both during and prior to the Aksumite Period, there was considerable landscape stability and resilience. This is reflected in the development of soils with vertic-like properties, which instead appear to be more like organic brown earths that gradually begin to aggrade through colluvial and alluvial additions. How much this is the result of sympathetic, long-term landscape management by the expanding population, and how much is related to underlying and longer-term climatic and vegetational trends is open to question at this stage. But in the last four to five centuries, the pace of alluvial aggradation appears to have increased markedly, and has deposited at least half of the sediment captured in the valley systems and lower slopes to the north of Aksum. This no doubt reflects a growing population and arable intensification.