Iron oxides and other associated minerals (ochre) were widely used in ancient times, however, the use and procurement of these materials is not well understood and there has been little research on the elemental characterization of the material compared to other artifact classes. To assess the possibility of identifying ochre differences between locations, the original potential geological sources should be thoroughly characterized. This paper describes the collection of potential geologic sources of ochre in the Tucson basin of Arizona, sampling of those sources, instrumental neutron activation analysis (INAA), and subsequent multivariate analysis of the data. This paper has several goals, including characterizing geochemical trends within and between ochre sources, identifying the important elements in geochemical characterization of ochre, and establishing a database for further investigations. This preliminary study indicates that the inter- and intra-source variations in geological sources of ochre in the Tucson basin region can be differentiated. Future analysis of iron oxide artifacts will be performed to examine correlations between artifacts and sources and provide a basis for further deductions concerning ancient ochre procurement.

Chemical sourcing is becoming an increasingly important component of archaeological investigation. Instruments used for elemental analysis generally must be operated in a controlled laboratory environment. Further, many methods require destruction of a small portion of the objects under investigation. These facts inhibit the application of chemical sourcing studies in a number of research contexts. Use of portable non-destructive instruments would resolve these issues. Sixty-eight obsidian artifacts from the site of Jiskairumoko, in southern Perú, were examined by X-ray fluorescence spectrometry (XRF) and portable X-ray fluorescence spectrometry (PXRF). Results were compared for consistency in terms of source determination and individual element concentrations. Both instruments determined that the same sixty-six artifacts derived from the Chivay obsidian source and both identified the same two artifacts that could not be assigned to source. Individual element comparisons showed significant differences, but these can be resolved through instrument cross calibration, and differences had no bearing on source identification. PXRF was found suitable for determining obsidian sources in southern Perú and for identifying specimens that require more sensitive analytical methods such as, instrumental neutron activation analysis (INAA). Regular use of Chivay at Jiskairumoko suggests consistent trade relationships developed during the Archaic.

The provenance postulate states that artifact raw material sources can be determined by chemical characterization as long as between-source chemical differences exceed within-source variation. For ceramics, successful differentiation of sources usually requires the measurement of a large suite of elements. While laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) can provide concentration data for nearly every element whose concentration is at or above 100 ng/g, it requires the use of “matrix matched” standards for quantitative analysis. In this work, we report on the use of micro-PIXE to develop standards for the microanalysis of ceramics by LA-ICP-MS.

The basic hypothesis being tested is that, in Alzheimer's disease (AD), the delicate balance of brain Zn is disrupted and may play a role in the pathogenesis of neuron degeneration. Micro-PIXE measurements reveal a significant elevation of Zn in senile plaques (SP) in AD brain compared with adjacent neuropil and a significant increase in AD neuropil compared to control neuropil. The observation of elevated Zn in SP is of interest because the amyloid precursor protein contains a Zn binding site that may prevent normal cleavage leading to the generation of a toxic fragment of beta amyloid, the constituent of SP. The potential of using laser-ablation inductively coupled plasma mass spectrometry as a complimentary microprobe technique is also presented.

k0 Instrumental Neutron Activation Analysis (k0 INAA) was evaluated at the University of Missouri Research Reactor (MURR). The MURR, unlike many other research reactors that employ k0 INAA, is refueled on a weekly basis. To determine if the neutron spectrum is stable enough for routine k0 INAA analysis, the neutron spectrum parameters α and f were measured over a 9 month period. The average values of f and α measured using the Cd ratio multi monitor technique were 57.4±4.5 and 0.039±0.012, respectively. It was determined that k0 INAA could be used at the MURR by employing the average value of α and f. However, significant measurement bias could occur for elements with high Q0 values if the true spectral parameters deviate by more than 10% from the average value.