The age of large termite mounds-radiocarbon dating of Macrotermes falciger mounds of the Miombo woodland of Katanga, DR Congo

The age of four large termite mounds has been determined by ¹⁴C-dating the acid-insoluble organic carbon fraction of samples taken along the central vertical axis of two active and two abandoned mounds. The age sequence in the active mounds is erratic, but the results for the abandoned mounds show a logical increase of ¹⁴C-age with depth. The ages measured at 50cm above ground level were 2335-2119calyr BP for the large abandoned mound (630cm high), and 796-684calyr BP for the small abandoned mound (320cm high). Cold-water-extractable organic carbon (CWEOC) measurements combined with spectroscopic analysis revealed that the lower parts of the active mounds may have been contaminated with recent carbon that leached from the active nest. Nonetheless, this method appears to provide reliable age estimates of large, abandoned termite mounds, which are older than previously estimated. Furthermore, historical mound growth rates seem to correspond to past temperature changes, suggesting a relation between past environmental conditions and mound occupancy.