Jamie Inwood & Gabriel Prieto

This project aims to elementally characterize a series of beads excavated from the archaeological site of Pampas Gramalote which is situated near the modern fishing village of Huanchaco in the Northeast coast of Peru. A sample possibly containing copper ore and secondary mineral excavated in the region from a deposit associated with the Moche period will also be characterized. The elemental composition of each of the beads will be compared to that of the ore (?) sample as well as similar published mineral specimens taken from other sources in Peru. Our intention is to shed light on the local and non-local sources and trade pathways of these materials.

The beads, dated to 15000-1200 cal bc, exhibit multiple color phases both within the assemblage and individually, ranging from blue/green to dark brown. Initial investigations using qualitative pXRF analysis have identified differing elemental compositions between individual beads in the assemblage. However, the spot size for portable X-ray fluorescence analysis is too large to identify any elemental shifts associated with different color phases within each bead. More in depth analysis must be done in order to isolate compositional variations present within the sample set and possibly within individual samples.

We intend to analyze the beads and ore sample using Energy Dispersive Spectroscopy on a scanning electron microscope in order to identify the elements comprising each bead as well as assess homogeneity within each sample. This will be done by analyzing areas exhibiting coloration change in each separate bead and the ore specimen. This information will be compared to published information of similar materials excavated in the North East Coast in order to isolate any patterns indicative of local or long distance trade as well as identify potential sources of the raw material.