Sources of Archaeological Obsidian in the Southwest: An Archaeological, Petrological, and Geochemical Study

1988 ◽  
Vol 53 (4) ◽  
pp. 752-772 ◽  
Author(s):  
M. Steven Shackley
Keyword(s):  
New Mexico ◽  
San Francisco ◽  
Volcanic Field ◽  
Technical Problems ◽  
X Ray ◽  
Northern Arizona ◽  
Geochemical Study ◽  
Chemical Variability ◽  
Geochemical Studies ◽  
Silicic Glass

Comprehensive geochemical studies of archaeological obsidian sources in the Southwest typically have lagged behind other regions of North American and Mesoamerica. Current archaeological and petrological research indicates four previously unreported sources in Arizona, Sonora, and western New Mexico. This initial semiquantitative X-ray fluorescence (XRF) examination of archaeological silicic-glass sources in this region focuses on current technical problems in southwestern obsidian studies. The chemical variability within some regional obsidian sources appears to be relatively extensive and new data from the San Francisco volcanic field in northern Arizona modifies the results of earlier researchers.

Trace and Minor Element Analysis of Obsidian from the San Francisco Volcanic Field Using X-Ray Fluorescence

1981 ◽  
Vol 25 ◽  
pp. 121-126 ◽  
Author(s):  
Suzanne C. Sanders ◽  
John D. Zahrt ◽  
Graydon Bell
Keyword(s):  
San Francisco ◽  
Fluorescence Analysis ◽  
Minor Element ◽  
Archaeological Site ◽  
Volcanic Field ◽  
Element Analysis ◽  
X Ray ◽  
Northern Arizona ◽  
Depth Study ◽  
San Francisco Volcanic Field

AbstractObsidian from eight localities in the San Francisco volcanic field of Northern Arizona was analyzed for 21 minor and trace elements (Ti, Mn, Fe, Co, Zn, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, W, Au, Hg, Th) usincf x-ray fluorescence analysis. All samples exhibited irregular analyzing surfaces. This was a more in-depth study of a previous study (1) in which a very small number of standards were used.The data, in the form of intensity ratios relative to iron, were statistically analyzed and the trace and minor element patterns established. The obsidian clustered into four well-defined groups each consisting of two localities: Government Mountain/Obsidian Tank, Slate Mountain/Kendrick Peak, Robinson Crater/O'Leary Peak, and RS Hill/Spring Valley. The four distinct groups were treated individually to refine the separation between the similar sites. Classification function coefficients were calculated for each locality, then used to identify the source of thirteen obsidian artifacts recovered from a Northern Arizona archaeological site.

X-Ray Analysis of Frozen Hydrated Sections:The Unconventional Approach

1982 ◽  
Vol 40 ◽  
pp. 754-757
Author(s):  
R. Beeuwkes ◽  
A. Saubermann ◽  
P. Echlin ◽  
S. Churchill
Keyword(s):  
Ratio Method ◽  
Frozen Sections ◽  
Technical Problems ◽  
Sample Handling ◽  
X Ray ◽  
Common Group ◽  
Ideal Method ◽  
Classic Paper ◽  
Physical Principles ◽  
The Ideal

Fifteen years ago, Hall described clearly the advantages of the thin section approach to biological x-ray microanalysis, and described clearly the ratio method for quantitive analysis in such preparations. In this now classic paper, he also made it clear that the ideal method of sample preparation would involve only freezing and sectioning at low temperature. Subsequently, Hall and his coworkers, as well as others, have applied themselves to the task of direct x-ray microanalysis of frozen sections. To achieve this goal, different methodological approachs have been developed as different groups sought solutions to a common group of technical problems. This report describes some of these problems and indicates the specific approaches and procedures developed by our group in order to overcome them. We acknowledge that the techniques evolved by our group are quite different from earlier approaches to cryomicrotomy and sample handling, hence the title of our paper. However, such departures from tradition have been based upon our attempt to apply basic physical principles to the processes involved. We feel we have demonstrated that such a break with tradition has valuable consequences.

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