High precision isotopic analyses of lead ores from New Mexico by MC-ICP-MS: implications for tracing the production and exchange of Pueblo IV glaze-decorated pottery

Between ca. 1275 and 1700 CE, Pueblo groups in the northern Southwest United States produced and exchanged ceramic bowls decorated with lead-based glaze paints. Previous studies of these glaze-decorated bowls have used lead isotopic analysis by ICP-MS to identify the sources of lead used by Pueblo potters, and investigate how social or economic factors may have influenced resource use among different Pueblo communities (e.g. 13 and 14; Huntley et al., 2007; Huntley, 2008). However, interpretations of much of this isotopic data have remained provisional because of overlap among the isotopic ratios of potential sources and because the isotopic composition of many glaze paints do not clearly match any known source. Here, we use multi-collector ICP-MS to re-measure the lead isotopic composition of 48 samples of lead sulfide (galena) and lead carbonate (cerussite) from sources in New Mexico that were potentially utilized by Pueblo potters, including mines within the Cerrillos Hills, Magdalena, Hansonburg, and Joyita Hills mining districts. These results define the isotopic composition of lead ores from these districts with greater precision and accuracy than achieved in previous studies and better distinguish among these mining districts in lead isotope space. Most significantly, we find that galena mineralization within the Cerrillos Hills only has a modest degree of isotopic variation, with ²⁰⁶Pb/²⁰⁴Pb ratios from 18.508 to 18.753, ²⁰⁷Pb/²⁰⁴Pb ratios from 15.580 to 15.607, and ²⁰⁸Pb/²⁰⁴Pb ratios from 38.388 to 38.560. These ranges are far narrower than previously reported, and should supersede previously published values for this district. In total, we conclude that isotopic measurements of both ores and glaze paints made by MC-ICP-MS will provide new information about the provenance of lead in glaze paints and allow for more detailed interpretations about resource procurement and exchange in the Pueblo world.     

Lead isotope analysis as a new method for identifying material culture belonging to the Vázquez de Coronado expedition

Archaeological evidence has become an increasingly important component of efforts to identify the route of the Francisco Vázquez de Coronado expedition through northern Mexico and the southwestern United States (1540-1542). Here, we report the first high-precision lead isotopic measurements of artifacts from two archaeological sites with strong material evidence for the expedition’s presence: Piedras Marcadas Pueblo in New Mexico and the Jimmy Owens Site in Texas. The analysis of lead and copper armaments from both sites reveals that many artifacts have overlapping or extremely similar isotopic ratios. We propose that the narrow range of lead isotopic ratios measured on these artifacts can be interpreted as a geochemical fingerprint for some of the Coronado expedition’s surviving material culture, and provides evidence that we interpret to suggest the expedition derived lead and copper metal from Mexican sources. Such a geochemical fingerprint presents an empirical method for discriminating between artifacts that belonged to the Coronado expedition and those related to subsequent Spanish, historical, or modern activity in the Southwest U.S. Thus, this method could significantly impact the search for and identification of archaeological sites associated with the Coronado expedition.     

Sub-regionalism in the Newly Independent States

Since 1989, six new sub-regional cooperation groups have emerged as the states of northern, central and eastern Europe work towards forging relationships with one another and their neighbours to east and west. Five of these groups are still in existence and have had considerable success in establishing cooperative relations in many areas outside the realm of purely military security. The authors suggest that such sub-regional groups could provide a useful model in the search for stability among the Newly Independent states of the former Soviet Union. Acknowledging and describing the ways in which this environment differs markedly form that of northern, central and eastern Europe, they point out the suitability of the model to the particular circumstances of the post-Soviet republics.     

Synchrotron radiation-based x-ray analysis of bronze artifacts from an Iron Age site in the Judean Hills

Seven bronze bangles from Tell en-Nasbeh, northern Judah, were investigated to understand the phase composition and manufacturing process of the artifacts, and possibly suggest a provenance for their origin. Synchrotron x-ray radiation diffraction (XRD) and fluorescence (XRF) were used in the analysis to avoid any destructive sampling and at the same time penetrate through the surface into the core metal. These techniques enabled us to determine that the bangles were not just tin bronze, but leaded tin bronze. Based on excavation reports, it is unlikely that the metal objects were manufactured locally at Tell en-Nasbeh; rather, preliminary XRD and XRF data point towards the neighboring region of Edom as their origin. Despite their political enmity during the Iron Age II, the data suggest that Judahite social demands for bronze may have fostered a strong economic relationship between these two polities.