Phytoliths in a Silo: Micro-botanical evidence from Zilum (Lake Chad Basin), NE Nigeria (C. 500 Cal BC)

Abstract

Phytoliths, amorphous silicon dioxide (SiO2, H2O), are durable and can be separated from layers where other plant remains fail like charcoal, pollen and seeds. A pit has been discovered empty of organic botanical material at the archaeological site of Zilum in NE Nigeria (600-400 cal BC). Zilum is one of several settlements of the so-called Gajiganna Complex (c. 1800-400 BC), the first food-producing society colonizing the fringes of Lake Chad. Unlike other analogous pits in the area, it was found bare of domestic refuses of any kind including charred organic (botanical) remains. An assemblage of fossil phytoliths of the family Poaceae has been separated from this pit using heavy liquid ZnBr2/HCl. Integration of the present results with earlier palaeoethnobotanical studies from the region is highly suggestive that this pit was used to store a Paniceae grass. © 2006 Asian Network for Scientific Information.