Structural and compositional analysis of a casting mold sherd from ancient China

Abstract

Casting had symbolic significance and was strictly controlled in the Shang dynasty of ancient China. Vessel casting was mainly distributed around the Shang capital, Yin Ruins, which indicates a rigorous centralization of authority. Thus, for a casting mold to be excavated far from the capital region is rare. In addition to some bronze vessel molds excavated at the Buyao Village site, another key discovery of a bronze vessel mold occurred at Daxinzhuang. The Daxinzhuang site was a core area in the east of Shang state and is an important site to study the eastward expansion of the Shang. Here, combining synchrotron X-rays and other physicochemical analysis methods, nondestructive three-dimensional structure imaging and different elemental analyses were conducted on this mold sherd. Through high penetration X-ray tomography, we obtained insights on the internal structure and discovered some pores. We infer that the generation of pores inside the casting mold sherd was used to enhance air permeability during casting. Furthermore, we suppose that the decorative patterns on the surface were carved and not pasted onto it. Considering the previous compositional studies of bronze vessels, the copper and iron elements were analyzed by different methods. Unexpectedly, a larger amount of iron than of copper was detected on the surface. According to the data analysis and archaeological context, the source of iron on the casting mold sherd could be attributed to local soil contamination. A refined compositional analysis confirms that this casting mold was fabricated locally and used for bronze casting.

Characterization of Ancient Burial Pottery of Ban Muang Bua Archaeological Site (Northeastern Thailand) Using X-ray Spectroscopies

“…Quantitative and/or semi-quantitative analyses for major, minor, and trace elements of archaeological materials are required to obtain information about manufacturing technology, raw materials, and origin of these objects as well as their restoration and conservation [3][4][5]. In previous research, many X-ray based techniques have been successfully used for analyses of the archaeological objects including X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), proton-induced X-ray emission (PIXE), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and X-ray tomographic microscopy (XTM) [3,[6][7][8][9][10][11].…”

Ancient Ceramic Casting Molds from the Southern Russian Far East: Identification of Alloy Traces via Application of Nondestructive SEM-EDS and pXRF Methods

“…The examination of these artifacts focuses, at first, on their morphological and technological features and properties. The usage of physicochemical methods, in particular, binocular and petrography microscopy, SEM-EDS analysis, XPS analysis, X-ray tomography, FTIR analysis, and some others, provide objective information on ceramic fabrics and firing regimes of casting molds [1][2][3][4][5][6][7][8].…”

“…Despite this, recognizing the alloy traces in ceramic molds is interesting and important archaeological evidence of the metalworking history. This refers to cases when discovered molds are single instances of the evidence of old metal processing and metalworking activities for studied archaeological sites or cultural communities [7,9,10].…”