Southern Belize has received less archaeological attention than other areas due in large part to its remote location. However, the difficulty in accessing the area in recent times does not necessarily equate to isolation for the Classic Period Maya who lived in what is now the Toledo District. This paper discusses petrographic data collected on ceramic vessels recovered from burial contexts at Uxbenká, Belize. The partial and reconstructed whole vessels from these primary contexts include locally produced vessels that are stylistically and technologically unique to the southern Belize region and vessels produced elsewhere. We use these data to evaluate how local Uxbenká potters produced ceramic vessels for local consumption and to identify long-distance interaction networks between Uxbenká and other regions of the Maya Lowlands. Our data indicate that most of the pottery at Uxbenká was produced locally. However, elite tombs often include both local and non-local vessels. The elites of Uxbenká engaged in interaction with people living much farther afield in regions like the Belize River Valley and possibly Guatemala.
more »
« less
Functional and Stylistic Considerations of Mixed Grog- and Shell-Tempered Late Mississippian Pottery from the Nashville Basin
Abstract Mississippian period ceramic assemblages in the Nashville Basin region of Tennessee are traditionally viewed as being overwhelmingly shell tempered. Our petrographic analyses of 30 ceramic sherds from three Middle Cumberland sites have revealed, however, the presence of grog, or crushed potsherds, in shell-tempered pastes in over 40% of our specimens. In our study, serving vessels are often tempered with both shell and grog, with one bowl rim containing solely grog. Cooking vessels tend to be tempered with coarse shell and contain only incidental grog. Grog tempering alongside shell has been only occasionally noted elsewhere in the regional literature, but the lack of its widespread recognition may be due to the difficulty of identification without the assistance of a petrographic microscope. It is not clear whether the addition of small grog particles to a shell-tempered paste offers any immediate functional advantages. Other studies suggest that grog temper could improve the workability of the clay, may reduce thermal shock, and may enhance a vessel's resistance to mechanical stress. The strong correlation of fine grog and shell temper with bowls, however, may constitute a low-visibility horizon marker for an extensive swath of the Late Mississippian culture area.
more »
« less
- PAR ID:
- 10412273
- Date Published:
- Journal Name:
- Midcontinental Journal of Archaeology
- Volume:
- 47
- Issue:
- 1
- ISSN:
- 0146-1109
- Page Range / eLocation ID:
- 47 to 67
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Zerboni, Andrea (Ed.)Late Pleistocene hunter-gatherers in East Asia adopted pottery, yet the ability to reconstruct circulation, mobility, and exchange has been hampered, in part, due to problematic regional geochronology. The driving forces behind pottery adoption is unclear. The purpose of this study is to test our results of the first systematic petrographic pottery sourcing from the pre-Younger Dryas by utilizing neutron activation analysis. We examine samples from the Sankauyama I site on Tanegashima Island, southern Japan, dating to the Incipient Jomon, ca. 14,000/13,500–12,800 cal BP, with a well-defined geochronology. Our NAA results corroborate with the petrographic study suggesting that pottery was mainly produced in-situ, but some vessels were transported long distances from another island. Changing from high mobility, sedentary Incipient Jomon foragers made pottery, occasionally investing in long-distance ceramic vessel transportation and exchange likely involving ocean crossing. This may be associated with a risk-buffering strategy in the context of rising sea levels and isolation of Tanegashima.more » « less
-
Abstract Temper bead (TB) welding is often used as an alternative to post weld heat treatment (PWHT) for repair of pressure vessels and piping in the nuclear power industry. Historically, qualification of TB welding procedures has employed the Charpy V-notch test to ensure acceptable heat-affected-zone (HAZ) impact properties. The 2004 Edition of ASME Section IX provided a new provision in QW-290 that allows temper bead qualification using a peak hardness criterion. The peak hardness provision is appropriate for industries such as oil and gas, where peak allowable hardness is specified to ensure adequate resistance to sulfide stress cracking in sour service environments. However, a peak hardness criterion is not appropriate where impact properties are specified for resistance to brittle fracture during low temperature conditions that can occur during certain postulated accident scenarios at a nuclear power plant. Work at the Electric Power Research Institute (EPRI) and The Ohio State University (OSU) show that a hardness drop protocol can be used to demonstrate acceptable impact properties in the HAZ of a temper bead weld. This paper presents a quantitative correlation between hardness measurements and HAZ microstructures with presumed optimum impact properties using a hardness drop approach. The overarching goal is to develop a hardness test protocol for temper bead weld procedure qualification for applications where impact properties are specified.more » « less
-
A simple Gaussian process regressor (GPR) model is employed to predict steel hardness and toughness response for tempered martensitic steels. A dataset of over 2000 hardness values from over 250 distinct alloys was compiled, with the aim of incorporating a diverse set of quenched and tempered martensitic steels. The Izod impact toughness was included for over 450 of these alloy/temper conditions. The GPR exhibited an increase in accuracy for both the predicted hardness and Izod impact toughness over linear regression trained on the same dataset. Shapley additive explanations (SHAP) were used to assess the importance of the input features of tempering temperature, tempering time, and 15 elements. Tempering temperature and carbon content were the most important input features in all models. The relative importance of the other 14 alloying elements varied depending on the target property. The SHAP analysis highlighted the complex relationships between composition and mechanical properties that are able to be captured by machine learning approaches.more » « less
-
null (Ed.)High permittivity polymer-ceramic nanocomposite dielectric films take advantage of the ease of flexibility in processing of polymers and the functionality of electroactive ceramic fillers. Hence, films like these may be applied to embedded energy storage devices for printed circuit electrical boards. However, the incompatibility of the hydrophilic ceramic filler and hydrophobic epoxy limit the filler concentration and therefore, dielectric permittivity of these materials. Traditionally, surfactants and core-shell processing of ceramic fillers are used to achieve electrostatic and steric stabilization for adequate ceramic particle distribution but, questions regarding these processes still remain. The purpose of this work is to understand the role of surfactant concentration ceramic particle surface morphology, and composite dielectric permittivity and conductivity. A comprehensive study of barium titanate-based epoxy nanocomposites was performed. Ethanol and 3-glycidyloxypropyltrimethoxysilan surface treatments were performed, where the best reduction in particle agglomeration, highest value of permittivity and the lowest value of loss were observed. The results demonstrate that optimization of coupling agent may lead to superior permittivity values and diminished losses that are ~2–3 times that of composites with non-optimized and traditional surfactant treatments.more » « less
An official website of the United States government

