Obsidian from eight localities in the San Francisco volcanic field of Northern Arizona was analyzed for 21 minor and trace elements (Ti, Mn, Fe, Co, Zn, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, W, Au, Hg, Th) usincf x-ray fluorescence analysis. All samples exhibited irregular analyzing surfaces. This was a more in-depth study of a previous study (1) in which a very small number of standards were used.
The data, in the form of intensity ratios relative to iron, were statistically analyzed and the trace and minor element patterns established. The obsidian clustered into four well-defined groups each consisting of two localities: Government Mountain/Obsidian Tank, Slate Mountain/Kendrick Peak, Robinson Crater/O'Leary Peak, and RS Hill/Spring Valley. The four distinct groups were treated individually to refine the separation between the similar sites. Classification function coefficients were calculated for each locality, then used to identify the source of thirteen obsidian artifacts recovered from a Northern Arizona archaeological site.