Far Western now offers X-ray Fluorescence (XRF) trace element analysis, using Bruker Tracer III SD portable XRF instruments. We focus on identification of geochemical signatures for identifying geological provenance, or source location, for archaeological toolstones. We maintain an extensive source library of obsidian and fine-grained volcanic rocks from the western United States, along with USGS geologic standards, to provide calibration. Far Western is committed to providing high-quality, reproducible, and publishable-quality results, following strict methodological protocols to ensure that our results are both precise and accurate.
Trace-element concentrations for the elements managanese, iron, zinc, rubidium, strontium, yttrium, zirconium, and niobium are generated with the MURR-2 matrix-specific calibration, developed by Bruker Elemental in collaboration with the University of Missouri Research Reactor or MURR (Glascock and Ferguson 2012; Speakman 2012). This factory-installed calibration is based on analysis of 40 samples of unmodified obsidian and fine-grained volcanic rock from around the world, chosen by Bruker and MURR to represent the range of trace-element concentrations known to occur in these materials. As in traditional full-sized or desktop instruments, source assignments may be made for artifacts as thin, or in some cases thinner than, 1.5 millimeters. For inter-lab consistency, we report independently measured trace-element concentrations with standard deviations for RGM-2, a USGS international rock standard.
Glascock, Mike, and Jeff Ferguson
Report on the Analysis of Obsidian Source Samples by Multiple Analytical Methods. University of Missouri Research Reactor, Columbia.
Speakman, Robert J.
Evaluation of Bruker’s Tracer Family Factory Obsidian Calibration for Handheld Portable XRF Studies of Obsidian. Prepared for Bruker AXS, Kennewick, Washington.
- $23 per sample
- 2-4 week turnaround
- Electronic report with data tables
- $300 minimum charge.
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