Abstract: Compositional analysis of materials adhering to fossil bones is a very complex type of research. In this work, a layer of black covered the surface of fossil bones from a red clay stratum at the Bailong Cave Site in Yunxi County, Hubei Province. The result of this research showed that this substance was composed of Ca10(PO4)3(CO3)3(OH)2, CaCO3, FeCO3, Fe2O3 and Fe25(PO4)14(OH)24 by spectral analysis using SEM/EDS, FIR and XRD. The color phases that were associated were minerals of FeCO3, Fe2O3 and Fe25(PO4)14(OH)24. The form of the black substance was related to CO32-and Fe in the adhering soil. It is noted that presence of the black substance stopped the strong corrosion of comparatively complete fossil bones in this high- energy chemical environment.

Key words: Fossil; Bones; Minerals; SEM/EDS; FIR; XRD