The archaeological site at Vohemar in a regional geographical and geological context

A major necropolis, discovered in the late 19th century at Vohemar, is located on a peninsula along the east coast of northern Madagascar. Excavations in the past century suggest that a prosperous civilization — the Rasikajy — buried their dead at this cemetery. The civilization seems to have disappeared from the region probably sometime in the 16th century. We discuss the regional geographical and geological context of the archaeological site at Vohemar in an attempt to better understand the collapse of the Rasikajy civilization. Furthermore, we discuss the mineral resources of northern Madagascar and show that raw materials such as chlorite-schist, pure quartz, iron, copper, silver and gold — used in the production of burial objects unearthed from the necropolis — occur in the hinterland of Vohemar. This suggests that the Rasikajy did not only produce “chlorite-schist” objects from material obtained at regional quarries, but possibly also manufactured iron, copper, gold, silver, bronze and quartz objects from raw materials mined in the region. Historical documents of the late 18th century suggest that the port of Vohemar was destroyed at some time in the past by a flooding event, and we tentatively speculate that this natural disaster caused the disappearance of the Rasikajy civilization and possibly also led to submergence of land north of the present-day town. It is clear, however, that more detailed archaeological and geological studies are necessary to elucidate the collapse of the Rasikajy civilisation.