Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

The social aspect of modern hominin behaviour is a neglected subject within recent Palaeolithic research. This thesis addresses this issue arguing that modern social behaviour is reflected in the hominin ability to create and maintain extended social networks where relatedness is successfully sustained in absentia. Archaeologically, modern social behaviour can be detected through the investigation of raw material movement. This thesis argues that by concentrating on materials that are rare, distinctive and their origins can be securely identified it is possible to reconstruct the dimensions of the exchange networks involved in their circulation. The proposition being tested is that the greater the distances of raw material movement the more advanced the behavioural abilities of the individuals involved in the transfers. Obsidian provides an opportunity to reconstruct the scale of its movement and to use these data to infer the changing scale of social life during the Palaeolithic. Using the distances of obsidian movement a network model is developed and used in the reconstruction of the Palaeolithic social landscape. This research brings together for the first time all the published instances of obsidian use during the Palaeolithic. Obsidian-bearing sites from the Palaeolithic and located in Africa, Europe and the Near East are analysed with the aim of elucidating the evolution of modern social behaviour. GtJi15 (Kenya) and Bodrogkerestúr (Hungary) serve as the case studies for the exploration of the distance effect on technological and typological issues of the obsidian movement. The research demonstrated a strong correlation between obsidian use and long distances. The choice of obsidian makes sense within a system of exchange in which hominins chose to obtain their materials from elsewhere in order to maintain social links with other, more distant, groups. I argue that the scale of obsidian movement, although conditioned by a number of climatic, ecological and anatomical constraints, is actually rooted in social grounds. I thereby reject theories that see behavioural modernity as a recent advance in human history and argue for modern behaviour as gradual process that was initiated in East Africa at least as early as the Middle Stone Age.

Obsidian was considered a very important resource by Mesoamericans and understanding the major source regions is a key step towards comprehense the economy of Mesoamerican regions. Mesoamerica is divided into nine sub‐regions according to the locations of major obsidian sources and Zaragoza obsidian source is the dominant supply in the Zaragoza‐Oyameles sub‐region. The aim of this paper is to present new investigations into the geology and geochemistry of the previously understudied Zaragoza obsidian source. Subsequent to this, comparisons between Zaragoza source and other major sources across central Mexico were made in order to understand the nature of Mesoamerican obsidian sources. During the study, we discovered three chemically different flows exited in the field with Zaragoza‐1 and Zaragoza‐2 match the previously reported Zaragoza obsidian with just some chemical variations possibly due to combined effects of fractional crystallization and some other magmatic process. However, Gomez Sur obsidian flow, which is exposed on the Northern part of the study area, displayed similar but not exactly same chemical signals has previously defined Altotonga obsidian, which was thought to be the product of the same magma system as the Zaragoza obsidian. Based on chemical similarities and the fact that the spatial relationship between previous altotonga sample collection points and our Gomez Sur outcrops, we hypothesize that Gomez Sur and Altotonga obsidians might both be products from earlier eruptive activities. The Heterogeneity Index (HI index) values of 12 obsidian sources across central Mexico indicates that the presence of another flow or sub‐flows in obsidian field might be a common scene across central Mexico. / 1 / Heng Hu

Universiẗat, Diss., 2002--Jena.

This Master’s thesis documents and interrogates networks of regional interaction in southwest Asia and Anatolia during the Neolithic and Chalcolithic periods (12,000 - 5700 B.P.) by comparing the variable use of obsidian raw material variants at 151 sites. This represents an effort to bring together all of the obsidian sourcing data produced for this broad archaeological setting, and evaluate it from a heterarchical approach that highlights the distributed nature of regional interaction. Heterarchical perspectives are applied here through the use of network analysis in order to highlight clusters of sites that are more connected to each other than they are to others in the system, and to determine the roles of each site in the system’s overall structure. As such, order is highlighted as a result of the organization of data-driven ties among sites, which are unrestricted by presumptions relating to geographical position or of pre-defined rank. The results are compared with more established models of regional interaction in the settings of interest, and heterarchical perspectives through network analysis are shown to complement common understandings of broad-scale connectivity at various points in time. / Thesis / Master of Arts (MA)

Not available

Thesis (Ph. D.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 7, 2007) Includes bibliographical references.

The physical properties and dynamic processes that control effusions of rhyolitic lavas are poorly constrained because of a paucity of direct observations. To assess the pre-eruptive storage conditions, eruptive ascent, and subaerial emplacement for a suite of volumetrically diverse rhyolitic lavas, I studied 10 obsidian lavas from Yellowstone Caldera, Wyoming and Mono Craters, California. Storage, ascent, and emplacement of those lavas were quantitatively constrained using phenocryst compositions, high temperature experiments, microlite textures, and compositional gradients surrounding spherulites. Compositions of phenocrysts and quartz-hosted glass inclusions indicate the magmas at Yellowstone were stored at 750±25 °C in the shallow crust (<7 km), in agreement with phase equilibria experiments. Following the initiation of an eruption, magma leaves the chamber and ascends in a conduit. Microlite number density can be used to quantify eruptive ascent rates. To generate the observed microlite number densities (10⁸·¹¹±⁰·⁰³) to 10⁹·⁴⁵±⁰·¹⁵ cm⁻³), the magmas decompressed at ~1 MPa hour⁻¹, equivalent to ascent rates of ~10 mm s⁻¹. Upon subaerial emplacement, microlites act as rigid particles in a deforming fluid (lava), and hence their 3D orientations could indicate flow direction and how strain accumulates in the fluid during flow. Microlites are strongly aligned in samples from all flows, but variations in alignment were found to be independent of flow volume or distance travelled. Together, those observations suggest that strains accumulated during subaerial transport must be small (<2). Instead, microlites most likely aligned in response to strain in the conduit, which can be generated by collapse and flattening. Upon reaching the surface, the cooling history and longevity of rhyolitic lavas are critical for developing models of emplacement and hazard assessment. Compositional gradients surrounding spherulites provide one method to assess such temporal characteristics. Spherulites, crystalline spheres of radiating quartz and feldspar, form by crystallization of obsidian glass in response to cooling. An advection-diffusion model was developed to simulate the growth of spherulites and compositional gradients that develop in the surrounding glass during spherulite growth. Observed gradients are consistent with spherulites growing between ~700 and ~400 °C, and cooling at rates of 10⁻⁵·²±⁰·³) °C s⁻¹. / text

This thesis examines the fabrication and provenance of 2,871 obsidian artifacts collected from twelve prehispanic archaeological sites in four physiographic zones throughout the Department of Chinandega, the northwesternmost department of Nicaragua. This research represents the first systematic study of obsidian artifacts in the region and focuses on two aspects of the obsidian artifacts. First, I present a macroscopic technical analysis of artifacts collected from twelve sites in the Department. The second part of the thesis presents a collaborative geochemical provenance study of obsidian procurement across these sites. Results indicate that most prehispanic sites participated in multiple sets of long-distance trade networks centered on obsidian as early as the Late Preclassic, up until the Late Postclassic, exploiting trade from four obsidian sources to the north. Analyses show that populations in the Department primarily, though not exclusively, utilized a core-flake industry that was worked on-site with material from the Güinope source in Honduras. A limited number of prismatic blades and a few other formal tools sourced from two additional further sources (La Esperanza in Honduras and Ixtepeque in Guatemala) appear almost exclusively as imported finished products more recently in the archaeological sequence. Additionally, the archaeological sites situated in the eastern coastal plains of the Department contained the largest variety of source material, followed by the sites of the northern foothills, a single site in the Nicaraguan depression, and lastly a single site in the Maribios volcanic front. Although ceramic analyses from the collection are partially complete and developing, this region is best understood as a cultural mosaic connected to the Mesoamerican populations in the north. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Universiẗat, Diss., 2004--Jena.