X-Ray Fluorescence Analysis as a Rapid Method of Identifying Tephras Discovered in Archaeological Sites

1981 ◽  
pp. 103-107 ◽  
Author(s):  
A. B. Cormie ◽  
D. E. Nelson ◽  
D. J. Huntley
1988 ◽  
Vol 42 (8) ◽  
pp. 1482-1487 ◽  
Author(s):  
J. J. Labrecque ◽  
J. E. Vaz ◽  
K. Tarble ◽  
P. A. Rosales

Radioisotope x-ray fluorescence analysis was performed to determine normalized elemental intensities for pre-Columbian sherds and roller stamps from different archaeological sites in the Middle Orinoco region of Venezuela. These normalized intensities were used to construct three-component (Triangle) graphs separating the sherds into three groups based on their known origin. The three-component graphs were: (Zn, Sr, Zr), (Rb, Sr, Zr), and ( A, Sr, Zr), where A = Cu + Zn + Pb normalized intensities. The total precision was shown to be better than 5% absolute for all cases studied. It was concluded that two of the roller stamps found at one site were probably manufactured in a different source area. This lends support to the notion that the roller stamps were a trade item in late pre-Columbian times (1000–1400 A.D.). The method applied in this study using a 109Cd (2 mCi) source seems to be appropriate for provenance studies of archaeological ceramics where many samples are processed, because it has the inherent advantages of being simple, economical, and rapid.


2011 ◽  
Vol 1319 ◽  
Author(s):  
Lesley Frame ◽  
Donna Bright DeSordao ◽  
Yuan-Chi Chiang ◽  
Pamela Vandiver

ABSTRACTFaience production methods include efflorescence, direct glaze application, and cementation glazing. However, similar processing has been used with a variety of other materials, such as glazed monolithic quartz, ground and re-fired faience, and steatite bodies. Furthermore, faience technology has been linked by similar processing to glass, synthetic pigment and glazing technologies. Here we reinforce these cross-craft relationships by comparing the range of similar functioning chemical elements in faience and glazed artifacts from a variety of archaeological sites that range from the Indus Valley to the Mediterranean. This broad comparative method based primarily on x-ray fluorescence analysis reveals trends in faience production, relationships with metallurgical technologies, and aspects of processing that provide areas of study that may be considered more closely in the future.


Author(s):  
D. A. Carpenter ◽  
M. A. Taylor

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.


Author(s):  
Allen Angel ◽  
Kathryn A. Jakes

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.


Author(s):  
M. D. Vaudin ◽  
J. P. Cline

The study of preferred crystallographic orientation (texture) in ceramics is assuming greater importance as their anisotropic crystal properties are being used to advantage in an increasing number of applications. The quantification of texture by a reliable and rapid method is required. Analysis of backscattered electron Kikuchi patterns (BEKPs) can be used to provide the crystallographic orientation of as many grains as time and resources allow. The technique is relatively slow, particularly for noncubic materials, but the data are more accurate than any comparable technique when a sufficient number of grains are analyzed. Thus, BEKP is well-suited as a verification method for data obtained in faster ways, such as x-ray or neutron diffraction. We have compared texture data obtained using BEKP, x-ray diffraction and neutron diffraction. Alumina specimens displaying differing levels of axisymmetric (0001) texture normal to the specimen surface were investigated.BEKP patterns were obtained from about a hundred grains selected at random in each specimen.


Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.


2020 ◽  
Vol 86 (10) ◽  
pp. 5-9
Author(s):  
D. G. Filatova ◽  
A. A. Arkhipenko ◽  
M. A. Statkus ◽  
V. V. Es’kina ◽  
V. B. Baranovskaya ◽  
...  

An approach to sorptive separation of Se (IV) from solutions on a novel S,N-containing sorbent with subsequent determination of the analyte in the sorbent phase by micro-x-ray fluorescence method is presented. The sorbent copolymethylenesulfide-N-alkyl-methylenamine (CMA) was synthesized using «snake in the cage» procedure and proven to be stable in acid solutions. Conditions for quantitative extraction of Se (IV) were determined: sorption in 5 M HCl or 0.05 M HNO3 solutions when heated to 60°C, phase contact time being 1 h. The residual selenium content in the solution was determined by inductively coupled plasma mass spectrometry (ICP-MS) using 82Se isotope. The absence of selenium losses is proved and the mechanism of sorption interaction under specified conditions is proposed. The method of micro-x-ray fluorescence analysis (micro-RFA) with mapping revealed a uniform distribution of selenium on the sorbent surface. The possibility of determining selenium in the sorbent phase by micro-RFA is shown. When comparing the obtained results with the results of calculations by the method of fundamental parameters, it is shown the necessity of using standard samples of sorbates to obtain correct results of RFA determination of selenium in the sorbent phase.


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