Eiland crucibles and the earliest relative dating for tin and bronze working in southern Africa

Over a century of research has demonstrated the historical importance of Rooiberg as a point source for tin production in preindustrial southern Africa. Current chronology suggests that the exploitation of the Rooiberg tin deposits began around AD1450 and continued into the 19th century. However, recent lead isotope and trace element studies of tin and bronze objects from AD1000 to 1300 sites, such as Great Zimbabwe and Mapungubwe, show that they were made with Rooiberg tin. Here we present technical analyses of two crucible sherds from Rhenosterkloof 3 near Rooiberg that were used in bronze production during the Eiland phase (AD1000-1300). The presence of tin bronzes during the Eiland phase indicates that Rooiberg tin was exploited from the early second millennium AD, almost three centuries earlier than previously believed, and affirms Rooiberg as an important source for bronze production in the southern African Iron Age.