Arleyn W. Simon

Acid Extraction As a Simple and Inexpensive Method for Compositional Characterization of Archaeological Ceramics

Although compositional characterization is now de rigueur in investigations of archaeological ceramics, the conventional means of characterization, instrumental neutron-activation analysis (INAA), is expensive and beyond the practical reach of many; demand has rapidly outstripped supply. Less expensive and more accessible methods have been employed with success, including atomic-absorption spectroscopy (AA) (Bower et al. 1975; Sheridan 1989; Torres et al. 1984; Tubb et al. 1980) and inductively coupled pled plasma emission spectroscopy (ICP) (Hart and Adams 1983; Har t ett al. 1991). Although easily available, these spectroscopic tools have not been widely used because the sample preparation methods for bulk analysis, requiring total dissolution of the ceramic, involve a great amount of labor and use extremely hazardous and toxic chemicals (Bower et al. 1975; Sheridan 1989). Here we present an inexpensive technique to obtain compositional attributes of archaeological ceramics that uses widely available instrumentation, but which does not require either the hazardous sample-digestion procedures or much labor. Soaking powdered ceramic samples in dilute acid for a few weeks at room temperature produces solutions that can be precisely reproduced. Although the acid does not totally dissolve the ceramic paste, extracts of ceramics made from the same clay produce chemically similar solutions, and different clays produce solutions with different compositions, such that the method can be reliably used to compare and distinguish ceramics. We have empirically observed in several dozen studies and thousands of analyses that the method does provide archaeologically significant information. Our initial tests indicate that the method can resolve ceramic production loci intraregionally, and that, using ethnoarchaeological data, the method can distinguish the wares of individual potters. Because a number of archaeological projects are already successfully using this method, a description of the method is presented at this time to encourage further exploration and evaluation. Choices of what ceramics to analyze, how many sherds, and what statistical methods are used

Salado Ceramic Burial Offerings: A Consideration of Gender and Social Organization

Archaeologists have often interpreted ceramic vessel accompaniments in burials as indicators of personal wealth or the social status of the decreased. However, alternative interpretations that are related to the gender and age of the individual may better explain the patterns of vessel placement. Ceramic vessel accompaniments recovered during the Roosevelt Platform Mound Study are used to examine gender roles among the prehistoric Salado of central Arizona. Patterns of vessel placement within Salado burials, as identified by compositional groups, have implications for the roles of individuals within the larger context of social relationships that comprised the prehistoric community.

Proton-induced x-ray emission analysis of turquoise artefacts from Salado Platform Mound sites in the Tonto Basin of central Arizona

During the Classic period (AD 1280–1450), prehistoric native Americans used turquoise for adornment, pigment and rituals at the Salado Platform Mound communities of the Tonto Basin in central Arizona. These rare, but valued, artefacts were obtained through social and trade connections to settlements and resource zones in adjoining and distant areas. We systematically examine the chemical signatures of turquoise artefacts to assess differences in access to turquoise sources between two large, competing Platform Mound communities (Cline Terrace Mound and Schoolhouse Point Mound) and determine whether they shared the same trade network. PIXE (proton-induced x-ray emission) is used to non-destructively characterize the chemical signatures of the turquoise artefacts; x-ray diffraction is used on a subset of artefacts to precisely identify mineralogical variability within copper-based blue-green minerals. Examples of multiple and mixed phases are further examined. These controlled chemical and mineralogical studies are used to guide the PIXE analysis of the larger dataset and to assess differences in source accessibility between the Cline Terrace and Schoolhouse Point Platform Mounds. Results indicate differential access to turquoise sources, similar to obsidian and decorated ceramics, and further delineate the regional social networks of this prehistoric culture.

Acquisition, representation, query and analysis of spatial data: a demonstration 3D digital library

The increasing power of techniques to model complex geometry and extract meaning from 3D information create complex data that must be described, stored, and displayed to be useful to researchers. Responding to the limitations of two-dimensional (2D) data representations perceived by discipline scientists, the Partnership for Research in Spatial Modeling (PRISM) project at Arizona State University (ASU) developed modeling and analytic tools that raise the level of abstraction and add semantic value to 3D data. The goals are to improve scientific communication, and to assist in generating new knowledge, particularly for natural objects whose asymmetry limit study using 2D representations. The tools simplify analysis of surface and volume using curvature and topology to help researchers understand and interact with 3D data. The tools produced automatically extract information about features and regions of interest to researchers, calculate quantifiable, replicable metric data, and generate metadata about the object being studied. To help researchers interact with the information, the project developed prototype interactive, sketch-based interfaces that permit researchers to remotely search, identify and interact with the detailed, highly accurate 3D models of the objects. The results support comparative analysis of contextual and spatial information, and extend research about asymmetric man-made and natural objects.

PIXE analysis of Salado polychrome ceramics of the American Southwest

Abstract Prehistoric Salado polychrome ceramics of the American Southwest show temporal variation in pigment use depending on location of manufacture during the Classic Period ( a.d. 1250–1450). Proton-induced X-ray emission (PIXE) analysis was undertaken to characterize chemical differences among Pinto, Gila, and Tonto Polychrome paints found in the Tonto Basin, Arizona. White slip samples on pottery from Roosevelt phase ( a.d. 1250–1320) sites are compared to samples from Gila phase ( a.d. 1320–1450) sites. A significant difference was found between the white slips used on the early (Pinto) versus the late (Gila and Tonto) Salado polychrome decorations, suggesting technological and economic changes in pottery manufacture over time.

Intraregional Connections in the Development and Distribution of Salado Polychromes in Central Arizona

Salado polychrome is associated with Classic period (A.D. 1270-1450) sites across much of the American Southwest, but its distributions are variable. Although multiple production centers are recognized for these decorated vessels, their roles in intraregional social networks are still open to interpretation. Recent compositional studies using petrography and weak-acid extraction ICP-MS compare locally produced wares to the characterization of Salado polychromes. Data from several adjacent study areas are used to assess the development and distributions of Pinto, Gila, and Tonto Polychromes. These decorated vessels are evidence of a highly differentiated intraregional network of exchange and communication which spanned the platform mound communities of central Arizona.

Shape modeling for 3D archaeological vessels

This chapter presents a method for archiving and searching three-dimensional Native American ceramic vessels using geometric modeling techniques. Archaeological vessels are scanned and defined as a set of 3D triangulated meshes composed of points, edges and triangles. Our work includes modeling the data with parametric surfaces, extracting features to raise the level of abstraction of data, and organizing vessel data based on XML schema. A visual query interface on the web was developed that permits users to sketch or select sample vessel shapes to augment text and metric search criteria to retrieve original and modeled data, and interactive 2D and 3D models.

Anthropological interpretations from archaeological ceramic studies : An introduction

For decades, ceramic analysis has been widely used in archaeological research of the American Southwest, but several recent ceramic studies have gone well beyond classification and material sourcing to examine the social relationships among ceramic exchange, production, and complexity. Presented here are studies from Classic period (A.D. 1270-1450) sites of central Arizona that focus on prehistoric social relationships among communities during times of population movement and aggregation. These recent research projects have made significant interpretive strides by examining ceramic change as an indicator of exchange pattern modifications and population shifts. These studies establish substantial databases of ceramic analyses and integrate results from complementary research methods to develop and test models of social interaction.