Analyses of a 20-30 cm thick, completely combusted ash at the 25 ?? 70 m Tschudi burn at Chan Chan, northern Peru??, contain 52-55 wt% SiO2, 180-210 ppm zirconium and are consistent with coal ash. Soil geochemistry across the burn showed elevated calcium and phosphorus content, possible evidence for reported human cremation. A calcined, 5 g, 4.5 cm skull fragment recovered from the burn was confirmed as human by protein radioimmunoassay (pRIA). X-ray diffraction showed that the bone had been heated to 520??C. The burn took place c. ad 1312-1438 based on interpretation of a 14C date on carbonized plant tinder. ?? 2008 University of Oxford.