X-ray Fluorescence and Neutron Activation Analysis of Obsidian from the Red Sea Coast of Eritrea

The strategic location of Eritrea along the Red Sea coast and the Horn of Africa makes it an important place to study human prehistory over a long span of time. However, recurrent political instability and the environmental adversity in the region have hindered comprehensive archaeological investigation. Paleolithic research in Eritrea began after the country obtained independence from Ethiopia in 1991. Geological survey in the Abdur area, along the Gulf of Zula coast (Figure 1), identified Paleolithic artifacts embedded in reef limestone dating to ~ 125 Ka BP (Walter et al., 2000). Based on this evidence, human coastal adaptation during the Late Pleistocene has been proposed. To explore the archaeological potential of the region, surveys and excavations were recently initiated along the Gulf of Zula and Buri Peninsula portions of the Red Sea coast. The survey documented a series of prehistoric sites from coastal and inland contexts featuring Acheulian, Middle Stone Age (MSA) and Later Stone Age (LSA) artifacts (Beyin and Shea, 2007). The Acheulian and MSA Lithic assemblages include highly deflated surface scatters of handaxes, prepared core products and retouched points made on locally available materials such as basalt, shale, and rhyolite. These assemblages however, lack secured stratigraphic contexts and obtaining radiometric dating is problematical. Excavations at three sites, Asfet, Misse East and Gelalo NW (Figure 1) in 2006 produced archaeological deposits of LSA affinity with mollusk shell association. A large quantity of debitage, blades, bladelets, backed tools and microliths characterize the lithic artifacts. A few of the artifacts are shown in Figure 2. The LSA bearing archaeological strata have been dated to the Early Holocene by 14C (AMS)

Instrumental neutron activation analysis of postclassic and historic-period pottery from Soconusco, Chiapas, Mexico [abstract]

Abstract only availableThe study involved utilizing Instrumental Neutron Activation Analysis (INAA) at the University of Missouri Research Reactor (MURR) on 96 pottery samples from the post-classic Mayan (ca. 1000-1500 C.E.) and historic eras excavated from the Soconusco region of Southern Chiapas, Mexico. This was done in order to understand and map the long-distance trade networks of Mesoamerica via the unique chemical characteristics of pottery. The samples were irradiated according to MURR procedures and measured at specific intervals on a gamma-ray spectrometer to yield the relative concentration of elemental composition. The data obtained from the use of INAA has allowed for the creation of compositional groups according to the chemical signatures of the pottery. These groups were then compared with other compositional reference groups from throughout Mesoamerica accumulated within the MURR archives. The results indicate a complex and diverse trade relationship with post-classic pottery dominated by samples produced either locally or in the surrounding Chiapas, and historic pottery being imported across Mexico from Colonial New Spawn sites such as Puebla, Mexico City and perhaps as yet un-identified production centers. It is hoped that an increase in further comparative data will help in the locating of these additional pottery production centers. From these results, this study seeks to add greater depth to the discussion of inter-regional trade systems across Mesoamerica in both the post-classic and historic periods and enhance the conclusions drawn from those discussions

Chemical sourcing of prehistoric ceramics from Mesoamerica

Abstract only availableFor over 3000 years the Basin of Mexico has been a cultural core of Mesoamerica—the location of Teotihuacán, the Aztec capital, and modern Mexico City. Despite the region's enduring prominence, little is known about early interactions between its different cultures. This project investigates ceramic exchange in the Basin of Mexico during the Formative Period (1200-500 BC) by chemically sourcing ceramics from four sites in the northeastern corridor, the Teotihuacán Valley. Instrument Neutron Activation Analysis (INAA) was used to determine the elemental compositions of 105 pottery sherds. The concentrations of 33 elements were detected and ceramics were grouped according to elemental compositions. When the differences between groups were greater than differences within groups, the pottery within a group was assumed to have the same provenance. Thus the study determined the proportion of locally made pottery and identified samples that appear to be imports.U.S. Dept. of Energy Innovations in Nuclear Infrastructure and Education Summer MURR Undergraduate Research Scholarshi

First data on obsidian provenance at a Formative site in santa rosa de los pastos Grandes, puna oF salta, arGentina

Los estudios de procedencia de materias primas permiten de algún modo orientar las investigaciones sobre interacciones sociales. Las obsidianas constituyen una materia prima ideal ya que, desde el punto de vista de su composición química, cada fuente es altamente homogénea internamente, pero significativamen­te distintas entre ellas; y aunque los artefactos confeccionados en obsidianas tengan una amplia dispersión, las fuentes están acotadas geográficamente. Este trabajo pretende ser un aporte a la información sobre las dinámicas respecto a las esferas de interacción en la Puna argentina en momentos de producción inicial de alimentos (ca. 2500- 1500 AP). En primera instancia, se presentan los resultados del análisis por XRF sobre las obsidianas provenientes de excavaciones arqueológicas de Quebrada Alta en Santa Rosa de los Pastos Grandes, en la Puna de Salta. Luego se caracterizan y discuten los contextos de hallazgo.Analysis of raw material sources may guide research of social interaction. Obsidians constitute a good material since they are internally highly homogeneous in its chemical composition, while meaningfully different between sources, and though obsidian artifacts may have a wide scattered pattern, sources are geographically constrained. This paper is a contribution to the understanding of the interaction networks and their dynamics in the Puna of Argentina during early Formative period (ca. 2500- 1500 BP). We first present the results of XRF analysis carried on obsidian artifacts from Quebrada Alta in Santa Rosa de los Pastos Grandes, in Salta province’s Puna. Then we discuss this evidence within the frame of social interaction networks.Fil: Mercuri, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; ArgentinaFil: Glascock, Michael D.. University of Missouri; Estados Unido

First data on obsidian provenance at a formative site in Santa Rosa de los Pastos Grandes, Puna of Salta, Argentina

Los estudios de procedencia de materias primas permiten de algún modo orientar las investigaciones sobre interacciones sociales. Las obsidianas constituyen una materia prima ideal ya que, desde el punto de vista de su composición química, cada fuente es altamente homogénea internamente, pero significativamen­te distintas entre ellas; y aunque los artefactos confeccionados en obsidianas tengan una amplia dispersión, las fuentes están acotadas geográficamente. Este trabajo pretende ser un aporte a la información sobre las dinámicas respecto a las esferas de interacción en la Puna argentina en momentos de producción inicial de alimentos (ca. 2500- 1500 AP). En primera instancia, se presentan los resultados del análisis por XRF sobre las obsidianas provenientes de excavaciones arqueológicas de Quebrada Alta en Santa Rosa de los Pastos Grandes, en la Puna de Salta. Luego se caracterizan y discuten los contextos de hallazgo.Analysis of raw material sources may guide research of social interaction. Obsidians constitute a good material since they are internally highly homogeneous in its chemical composition, while meaningfully different between sources, and though obsidian artifacts may have a wide scattered pattern, sources are geographically constrained. This paper is a contribution to the understanding of the interaction networks and their dynamics in the Puna of Argentina during early Formative period (ca. 2500- 1500 BP). We first present the results of XRF analysis carried on obsidian artifacts from Quebrada Alta in Santa Rosa de los Pastos Grandes, in Salta province’s Puna. Then we discuss this evidence within the frame of social interaction networks