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Provenance research of archaeological ocher contributes to understanding the capabilities of prehistoric humans to select, process, and treat suitable raw materials for symbolic and utilitarian purposes. The western part of the Lessini Mountains in the Veneto region of northeast Italy is an ideal location for this type of study as it features several different Fe-rich deposits, and many examples of archaeological ocher have been found in the nearby Fumane Cave and Tagliente Rockshelter Upper Paleolithic sites. Sourcing areas are often identified through the use of geochemical studies; however, microscopic techniques can also be used with the benefit of providing more detailed information about accessory minerals and textural characteristics of the material. One of the goals of our study was to demonstrate the potential in using polarizing light microscopy supported by scanning electron microscopy coupled with an energy dispersive X-ray spectrometer in research of this type. We studied geological source samples and archaeological materials from the sites, the results of which are very promising in terms of shedding light on the sourcing of prehistoric ocher in this region. [ABSTRACT FROM AUTHOR]

Usually referred to in archaeological contexts simply as 'ochre', ferruginous rocks were commonly used during the Middle Stone Age (MSA) in South Africa. While ochre use by early modern humans has often been interpreted as reflecting complex behaviours, related procurement strategies and selection criteria remain poorly documented. Eight ochre sources from the surroundings of Diepkloof rock shelter in South Africa and 28 ochre pieces from the site's MSA levels were studied by XRD, ICP-OES and ICP-MS. Mineralogical and geochemical data demonstrate that ochre was both locally procured and transported to the site from more distant sources. Here, we investigate the reasons underlying the choice of particular local and non-local ochre sources exploited at Diepkloof, emphasizing differences in their physico-chemical properties. Regardless of the motivations behind ochre selection, our data shed new light on the behavioural complexity of MSA societies and suggest that ochre procurement strategies may be independent of subsistence concerns. [ABSTRACT FROM AUTHOR]

In this study, we compared the effectiveness of instrumental neutron activation analysis (INAA) of bulk ochre to laser ablation-inductively coupled plasma mass spectrometry of homogenized ochre chips (HOC LA-ICPMS) at distinguishing among three ochre sources in northern Malawi. Both techniques upheld the Provenance Postulate; however, HOC LA-ICPMS required less sample material than INAA and facilitated fast, inexpensive replicate observations that allowed for more robust statistical analysis. Our results indicated that HOC LA-ICPMS is a maturing technique that will be a valuable option for analysing artefacts that require minimally destructive sampling but are too large to fit into the laser cell for direct ablation. With regard to the statistical procedures used, stepwise canonical discriminant analysis was demonstrated to be a highly effective method for distinguishing among ochre sources, even in the presence of significant intra-source and intra-sample heterogeneity. Continued development of the HOC sample preparation technique will expand the range of archaeological ochre artefacts that can be included in provenance studies and prevent bias towards artefacts of convenient-to-analyse dimensions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Iron ochres are gelatinous sludges that can cause problems in terms of water management. In this work, the application of iron ochre obtained from a river has been applied to catalytically crack methane-another potential waste product-into two useful products, hydrogen and amagnetic carbon-containing composite. RESULTS: The powder X-ray diffraction (XRD) pattern of the iron ochre was found to be consistent with the expected 2-line ferrihydrite, and energy dispersive X-ray (EDX) analysis showed Fe to be a major component although some Si and Ca were present. The samplewas observed to contain a fractionwith a tubular morphology consistent with the presence of extra-cellular biogenic iron oxide formed by leptothrix. Upon exposure to methane at elevated temperatures, the material was found to transformintoanactive catalyst forhydrogenproduction yielding a magnetic carbon-containing compositematerial comprising filamentous carbon and encapsulating graphite. CONCLUSION: The application of two waste products-iron ochre and methane-to generate two useful products-hydrogen and a magnetic carbon-containing composite-has been demonstrated. Furthermore, the ochre has been shown to comprise tubular morphology extra-cellular biogenic iron oxide which may be of interest in terms of other applications. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is often used for non-destructive analysis of works of art, polymers and biological materials, but in some cases, the laser beam can cause damages on the surface being studied due to the deposited beam energy. When possible, such damage can be prevented by minimizing laser intensity or acquisition time, but this is usually available only on high sensitivity bench-top spectrometers. Portable Raman spectrometers are commonly not so flexible and an alternative is needed to ensure the safe study of sensitive works of art and other fragile materials. A helium jet aimed directly at the laser spot may prevent this damage from occurring and, in some cases, helps improving the Raman spectra. We designed a simple system (HERAS, Helium Raman System) consisting of a pinhole collimator, coupled to a helium line and a gas mass flux control and tested it on pyroxylin, vermilion and ochre paint references and pigment samples, using a 785 nm portable Raman spectrometer at various laser powers. Experimental conditions slightly differ for each sample, but small burns on the surface were avoided in all cases and only some ablation was observed on the most sensitive materials. The use of this coupled system allows the non-destructive application of Raman to a wider variety of materials, while the technique remains portable. This setup may be used in bench-top apparatus as well. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Ochre is a red mineral pigment that was a key element of social and ceremonial practices among cultures of the Pacific Northwest Coast. It is recovered routinely from archaeological excavations, is visible as pigment for pictographs, and is described in the historical record as a trade item and component of ceremonial practices. Despite its ubiquity in the archaeological record, it is difficult to interpret its significance without first understanding the nature of its procurement and distribution. As a step towards identifying procurement practices, trade and resource use, it is necessary to thoroughly characterize ochre outcrops with regard to their intra-source and regional variability. We analysed ochre from three outcrops using INAA to determine their elemental chemistry. The purpose of this study is threefold: to provide an example of the range of elemental variability within and between outcrops, to illustrate the effect of scale and geomorphological processes on elemental compositions and statistical interpretation, and to create a database of known deposits in southern British Columbia. The results demonstrate that ochre deposits may be differentiated on the basis of their chemistry, and that conservative statistical interpretation needs to be employed to assess true elemental variability within and between ochre deposits and regions. [ABSTRACT FROM AUTHOR]

The use of red ochre in the prehistoric architecture of Central Anatolia has long been recognized. Scholars have often argued that its use in architecture has a symbolic role, and that it has been used in sacred parts of ritual buildings. This paper examines red-painted buildings in the prehistoric settlements of Central Anatolia. Recently, a building with red-coloured plastered walls and floors was found in Chalcolithic Çatalhöyük West. The technique of Raman Spectroscopy has been applied to identify the red pigment and results show that it is red ochre, which contains predominantly hematite, FeO. [ABSTRACT FROM AUTHOR]

The article discusses the potential for ochre to sequester phosphorus in an environmentally sustainable fashion. Ochre deriving from coal mine drainage sites in the United Kingdom displays a high phosphorus retention capacity without highly mobilizing metals, indicating that it can potentially adsorb phosphorus from agricultural wastewaters and be used as a fertilizer. A study focused upon untreated acid mine drainage from an abandoned copper-sulfur mine in a catchment of southeast Ireland. Ochre was mixed with phosphorus-amended water in batch experiments and a maximum adsorption capacity was calculated from the Langmuir equation.

Ochres were the most common source materials for pigments used in Palaeolithic rock art paintings. This work analyses the petrographic and geochemical signatures of different ochre samples from outcrops inside Tito Bustillo Cave and the Monte Castillo Caves using the most common techniques (petrography, XRD, SEM–EDS and ICP–MS) in archaeological pigment characterization studies. The results obtained permit the identification and characterization of the different source ochre types and, furthermore, allow the establishment of mineralogical and geochemical proxies for the study of questions related to ochre characterization, formation processes and provenance. [ABSTRACT FROM AUTHOR]

The expansion of indigenous art and the interest it has generated both at a domestic and international level means large monetary transactions are taking place between art galleries or centers and purchasers. As such, an accurate and conclusive method for provenance determination of traditional indigenous artistic materials must be established that can, if necessary, be used to assist in authentication of artworks. Laser ablation inductively coupled plasma mass spectrometry was utilized for elemental differentiation and provenance establishment of ocher samples. This research was used to develop a robust scientific protocol which facilitates definitive and accurate determination of provenance of Australian ochers and the artworks created using them. Analysis of the results obtained through this study show that the trace metal distribution patterns alone appear to be sufficient evidence to establish provenance of specific ochers, although additional differentiation between ocher samples, using major element distribution patterns, was achieved through the utilization of X-ray analytical techniques. [ABSTRACT FROM AUTHOR]

A range of wetland plant species (44) was screened in solution culture experiments for sensitivity to large concentrations of supplied Fe. Two distinct root precipitates were observed (see 'Appendix' for a tabulated summary of symptoms). Energy dispersive spectroscopy showed that an ochreous precipitate was probably a hydrated ferric oxide whilst a pale yellow or yellow-grey one was an Fe P solid, possibly a ferric phosphate. Ochre precipitates were found almost exclusively on the roots of Fe-tolerant species and were particularly intense on the most tolerant ones. Monocotyledonous species (generally more Fe-tolerant than dicotyledonous species and with higher root porosities), tended to produce ochre most freely. The Fe-P precipitate was frequently found on roots of the less tolerant species and was particularly abundant on the most sensitive ones. Blackening of roots (with flaccidity), another common response of roots of Fe-sensitive plants exposed to large Fe concentrations, was not a result of any obvious external precipitate. There was no evidence that differential pH changes induced by roots helped to determine either Fe tolerance or the nature of the root precipitate observed. Roots of all species tested caused the pH of an agar medium to rise. Elevated Fe supply resulted in greater external acid phosphatase activity in roots of two test species. The increase corresponded with the species mean relative growth rate (RGR) (and presumed P requirement), and with the fertility of sites in which it grows. Chemical analyses of shoots and roots of four species of differing Fe tolerance showed that, with increasing Fe supply. mean shoot Fe concentrations increased significantly whereas for most other elements (except Na and Zn) a significant reduction in concentrations in th shoot was observed. [ABSTRACT FROM AUTHOR]

By treatment of Bacillus subtilis MO-101-P spoA- met thr- su- with ethyl methanesulfonate, a strong suppressor strain of nonsense mutations, B. subtilis MO-101-P spoA- [met-]+ thr- su+44, was isolated. This strain does not suppress phage Φ29 mutant susB47, selected on a B. subtilis strain containing the su+3 suppressor isolated by Georgopoulos. A revertant from this mutant, susB610, was isolated, being suppressed by both the su+3 and su+44 suppressor strains. The efficiency of suppression by strain su+44 is about 50%. The experiments shown in this paper suggest that strain su+44 contains an amber and strain su+3 an ochre suppressor. [ABSTRACT FROM AUTHOR]

An abstract of the study "Assessing the Performance of Phosphorus-Saturated Ochre as a Fertilizer and Its Environmental Acceptability," by K. E. Dobbie, K. V. Heal and K. A. Smith, published in the June 2005 issue of "Soil Use and Management" is presented.

SynopsisNatural antique colorants include mainly red pigments such as cinnabar and ochre. These archeological pigments were used especially as funeral and cosmetic makeup and are a material proof of handicraft activities and exchanges. The identification and characterization of a group of punic colorants, corresponding to samples discovered during excavations at several Tunisian archeological sites (Cartage, Ksour Essef, Kerkouane, Bekalta, Makthar, Bou Arada), were conducted using the least destructive analysis techniques such us scanning electron microscopy coupled to X-ray fluorescence microprobe, direct current plasma emission spectroscopy, atomic absorption spectrometry, Fourier transform infrared spectrometry and X-ray diffraction. Eleven natural red colorants from punic period were subject to this investigation and were compared to contemporary substances. Five colorants were cinnabar and the other six were ochre. [ABSTRACT FROM AUTHOR]