Mark Golitko

An Analysis of pXRF Obsidian Source Attributions from Tikal, Guatemala

Portable X-ray fluorescence spectrometry (pXRF) was used to obtain source determinations for 2,235 obsidian artifacts. These were supplemented by 48 previously published results made by X-ray fluorescence spectrometry (XRF) and instrumental neutron activation analysis (INAA) to bring the total sample to 2,283. Thirteen geological sources have been identified by instrument to date. Three sources in Highland Guatemala accounted for nearly 98 percent of all attributions, with approximately 2 percent from 10 green and gray obsidian sources in central Mexico. Geological sources can be brought into cultural context by examining their distributions among types of artifacts, recovery contexts, structure group types, distance from the Classic period epicenter of the city, and chronological relationships. Several procurement systems operated to import obsidian cores and other artifacts. Consumers obtained obsidian artifacts primarily through marketplace exchange, but other kinds of distribution are also indicated. The reliability, portability, rapidity, ease of use, non-destructive nature, and relatively low cost of pXRF show promise for the acquisition of the source attributions needed to construct the past cultural contexts of obsidian procurement and use. This method produces results comparable to those obtained by other kinds of instrumental analysis, and with a considerably higher degree of reliability than visual determinations.

Chapter 13: Provenience Investigations of Ceramic and Obsidian Samples Using Laser Ablation Inductively Coupled Plasma Mass Spectrometry and Portable X-Ray Fluorescence

Abstract Explaining the modern cultural and linguistic diversity present on the Sepik coast requires an understanding of long-term interaction on both a regional and a broader Melanesian scale. To assess the nature of prehistoric social networks, 438 obsidian specimens and 326 ceramic sherds collected from the coast and brought to the Field Museum of Natural History in Chicago were subjected to chemical analysis by either laser ablation inductively coupled plasma mass spectrometry or portable X-ray fluorescence. The results indicate that people living on the Sepik coast received obsidian from sources in the Admiralty group and on New Britain continuously for the past 2,000 years, and possibly as far back as the mid-Holocene. While obsidian from New Britain is more abundant in contexts believed to pre-date ∼2,000 BP, the more proximal Admiralty sources dominate later assemblages. Ceramic exchange may have begun between production centers on the coast as early as 2,000 years ago, and spanned the length of the coast by at the latest 1,000 BP. Regional differences in the degree and scope of exchange relationships evident in the recent past may have very ancient roots—the present data suggest that social networks on the coast were comparable to those ethnographically documented, and that sometimes quite proximal sites obtained materials from different sources or networks of exchange partners.

Pottery production, regional exchange, and state collapse during the Middle Horizon (A.D. 500–1000): LA-ICP-MS analyses of Tiwanaku pottery in the Moquegua Valley, Peru

Abstract During the Middle Horizon (A.D. 500–1000), the Tiwanaku state dominated the south central Andes. The production and circulation of goods were important components of statecraft. To date, studies of the movement of pottery vessels across the Tiwanaku realm have relied on stylistic analyses. This paper presents results of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) analyses of ceramics from the largest Tiwanaku province in the Moquegua Valley, Peru. Comparison of the derived compositional data with an existing chemical database of Moquegua Valley clays demonstrates that in addition to local production, non-local ceramic vessels were being brought into the valley during the height of Tiwanaku authority. A lower percentage of imported ceramics was identified in ceramic assemblages dating to the wake of Tiwanaku state collapse (ca. A.D. 1000). Long-distance exchange endured despite political breakdown but there were alterations in the particular networks in which post-collapse communities participated.

Recent Advances in Laser Ablation ICP-MS for Archaeology

This book explores different aspects of LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry). It presents a large array of new analytical protocols for elemental or isotope analysis. LA-ICP-MS is a powerful tool that combines a sampling device able to remove very small quantities of material without leaving visible damage at the surface of an object. Furthermore, it functions as a sensitive analytical instrument that measures, within a few seconds, a wide range of isotopes in inorganic samples. Determining the elemental or the isotopic composition of ancient material is essential to address questions related to ancient technology or provenance and therefore aids archaeologists in reconstructing exchange networks for goods, people and ideas. Recent improvements of LA-ICP-MS have opened new avenues of research that are explored in this volume.

Building Taypikala: Telluric Transformations in the Lithic Production of Tiwanaku

Stone configured Tiwanaku construction and identity. A vital component of Tiwanaku’s most important monuments, it defined Tiwanaku as a place and a people. Here we summarize ongoing geoarchaeological research into the lithic production of Tiwanaku monumentality. We discuss our research on stone quarrying and monumental production in light of previous investigation on the topic. We conclude that monumental stone production was critical to Tiwanaku’s emergence as a central urban center. A shift in lithic materials, sources, and quarrying technologies propelled Tiwanaku’s rise as a primary urban center during the Andean Middle Horizon. This was a transformation from sandstone, quarried in the nearby Kimsachata Mountains, to the strategic inclusion of more durable volcanic andesite, quarried in several new more distant locations including the extinct volcano Mount Ccapia. Our research attests the telluric foundation of Tiwanaku urbanism and cosmology, which originated in Late Formative centers and interaction networks. It also attests the importance of the contrasting materiality of two classes of stone—their differing colors and durabilities, technologies of monumental production, and montane places of origin—for Tiwanaku’s emergent centrality and cosmology.

Expanded Applications of Laser Ablation-ICP-MS in Archaeology

This chapter briefly reviews novel and expanded archaeological applications of LA-ICP-MS as presented in the chapters in Part IV of this volume.

Sources and semiotics: obsidian studies in North-east Asia and Mesoamerica

These two volumes represent very different approaches to obsidian studies in archaeology. The papers in Methodological issues, edited by Ono et al., are concerned with the practical aspects of sourcing obsidian in North-east Asia (Japan, Korea, north-eastern China and fareastern Siberia); those in Obsidian reflections, edited by Levine and Carballo, are primarily concerned with how to approach the meaning and significance of obsidian to people living in Mesoamerica, both before and after Spanish incursion (c. AD 1520). Obsidian has long been of interest to archaeologists as a means of approaching the past, although it may not be too much of a stretch to suggest that assigning archaeological obsidian pieces to geological sources has been the primary focus for decades.

Positive effects of refugee presence on host community nutritional status in Turkana County, Kenya

Refugee camps are often assumed to negatively impact local host communities through resource competition and conflict. We ask instead whether economic resources and trade networks associated with refugees have benefits for host community health and nutrition. To address this question we assess the impacts of Kakuma Refugee Camp in northwest Kenya, comparing anthropometric indicators of nutritional status between Turkana communities in the region.

Population is the main driver of war group size and conflict casualties

Significance Recent views on violence emphasize the decline in proportions of war groups and casualties to populations over time and conclude that past small-scale societies were more violent than contemporary states. In this paper, we argue that these trends are better explained through scaling relationships between population and war group size and between war group size and conflict casualties. We test these relationships and develop measures of conflict investment and lethality that are applicable to societies across space and time. When scaling is accounted for, we find no difference in conflict investment or lethality between small-scale and state societies. Given the lack of population data for past societies, we caution against using archaeological cases of episodic conflicts to measure past violence. The proportions of individuals involved in intergroup coalitional conflict, measured by war group size (W), conflict casualties (C), and overall group conflict deaths (G), have declined with respect to growing populations, implying that states are less violent than small-scale societies. We argue that these trends are better explained by scaling laws shared by both past and contemporary societies regardless of social organization, where group population (P) directly determines W and indirectly determines C and G. W is shown to be a power law function of P with scaling exponent X [demographic conflict investment (DCI)]. C is shown to be a power law function of W with scaling exponent Y [conflict lethality (CL)]. G is shown to be a power law function of P with scaling exponent Z [group conflict mortality (GCM)]. Results show that, while W/P and G/P decrease as expected with increasing P, C/W increases with growing W. Small-scale societies show higher but more variance in DCI and CL than contemporary states. We find no significant differences in DCI or CL between small-scale societies and contemporary states undergoing drafts or conflict, after accounting for variance and scale. We calculate relative measures of DCI and CL applicable to all societies that can be tracked over time for one or multiple actors. In light of the recent global emergence of populist, nationalist, and sectarian violence, our comparison-focused approach to DCI and CL will enable better models and analysis of the landscapes of violence in the 21st century.

Reassessing the environmental context of the Aitape Skull – The oldest tsunami victim in the world?

There is increasing recognition of the long-lasting effects of tsunamis on human populations. This is particularly notable along tectonically active coastlines with repeated inundations occurring over thousands of years. Given the often high death tolls reported from historical events though it is remarkable that so few human skeletal remains have been found in the numerous palaeotsunami deposits studied to date. The 1929 discovery of the Aitape Skull in northern Papua New Guinea and its inferred late Pleistocene age played an important role in discussions about the origins of humans in Australasia for over 25 years until it was more reliably radiocarbon dated to around 6000 years old. However, no similar attention has been given to reassessing the deposit in which it was found—a coastal mangrove swamp inundated by water from a shallow sea. With the benefit of knowledge gained from studies of the 1998 tsunami in the same area, we conclude that the skull was laid down in a tsunami deposit and as such may represent the oldest known tsunami victim in the world. These findings raise the question of whether other coastal archaeological sites with human skeletal remains would benefit from a re-assessment of their geological context.