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  • Author or Editor: R. Hancock x
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Abstract  

To study the nature of ancient and modern pottery it is necessary to be able to determine the concentrations of the major constituent elements. For such studies, mass balances calculated from these elemental concentrations cluster around 100% for a silicate-silica matrix and around 80–90% in highly calcarious pottery which has a silicate-carbonate (silica) matrix. This work requires experimental measurements with coefficients of variation wihtin approximately ±5%. The high concentrations of silicon in pottery may reasonably be determined by neutron activation analysis using the nuclear reaction29Si(n, p)29 Al. Aluminium-29 has a half life of 6.56 minutes and a γ-ray energy of 1272 keV. Epithermal neutron irradiations of samples in cadmium foil are required to minimize the quantities of thermal neutron induced radionuclides. The method of analysis developed for the low flux SLOWPOKE reactor is described and the accuracy and precision of the technique is discussed by allusion to analyses of standard reference materials. The application of this technique to two different archaeological problems is addressed. The first is a case of carbonate dilution found in neolithic pottery from Iran and the second case is a problem of silica dilution in Roman pottery from Germany.

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Concentrations of major, minor and trace elements were measured in four soil profiles from south-central Ontario. The mean concentration values reported are probably representative of elemental levels in soils formed from sediments reworked by lacustrine and fluvial processes and weathered over the last 12 000 years. The older soils in the sequence (R12, R15 and BRIM1) show declining Na, K, and Al, mainly from Ca dilution, especially in the lower horizons. Iron and Mg levels were not affected by the variations in the Ca concentrations. Arsenic, Br, and Sb concentrations did not increase appreciably in surface A horizons, indicating no measurable airfall influx of industrial pollutants. The relative increase in Mn/Al in the lower horizons of the older soils may be related to leaching by soil or ground water movement.

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A stratigraphic and geochemical study of alpine soils, which formed in later Pleistocene (late glacial) and Neoglacial deposits in the Wind River Mountains of western Wyoming, indicates that these soils have been affected by air-fall influx of inorganic pollutants. Arsenic, bromine, and antimony appear to have been deposited in surface soils by incorporation of aeolian materials which were presumably transported by prevailing winds from industrial sources, including coal-burning operations. Because vanadium was not found in surface soils at concentrations above site-specific background levels, oil-fired energy generating stations were not deemed to be significant sources of surface soil pollution in the region. Acid-rain effects were not observed in the soils.

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Abstract  

Ninety-two samples of ceramics from Kommos in south-central Crete, covering the Middle Minoan periods MMI to MMIII have been analyzed by instrumental neutron activation using the SLOWPOKE reactor at the University of Toronto. The sherds represented three basic fabric types: a fine buff fabric, a stone tempered buff fabric, a coarse, stone tempered red fabric. Also included in the study were three sherds from nearby archaeological sites and six Kommos sherds which were archaeologically assessed as exhibiting atypical fabrics. The three fabric types were sortable into two distinct chemical groups, and two similar groups. Little temporal variation in chemical composition was found in the fine buff wares, and the atypical fabrics fitted neatly into three of the chemical groups.

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Abstract  

After 21 years of operation at the University of Toronto, the SLOWPOKE Reactor Facility is still used predominantly for the neutron activation analysis of a wide range of samples in both research and undergraduate teaching laboratories. A large number of researchers and students continue to take advantage of the five on-site gamma-ray spectrometers available for general use. The usage patterns of the low flux SLOWPOKE-2 reactor are addressed and an assessment is made of the relative continuing usefulness of the reactor facility to a range of research areas and teaching groups, with specific examples to illustrate the broad cross-section of use.

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Abstract  

Twenty samples of millstones made from volcanic lavarecovered from two Roman villa sites in southern Italy, covering the period IInd/Ist century BC, have been analyzed by instrumental neutron activation using the SLOWPOKE reactor at the University of Toronto. Also included in the studies were three samples of lava from an extinct volcano located in the same region. Findings are compared with published data on trace element compositions from a number of Mediterranean volcanic sources. Results show the provenance of the millstones to be from two different Italian sources.

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Abstract  

Palaeosols and soils of early Holocene (9,000–10,000 yr BP) and Neoglacial (<1200 yr BP) ages from three sections in the Okstindan Mountains in central Norway were analyzed to determine their geochemical compositions. Four buried horizons and a surface sample all had significant water/organic contents. The highest Br (and also Th, U and possibly the REEs) contents were associated with the highest water/organic contents. From the rare earth and other elemental concentration variations, it appears that the three sections were formed from three parent materials, different horizons of which have been affected by weathering and plants.

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Abstract  

During the course of field work in the Chamonix-Argentière area of the Western Alps of France, low pH's (by field testing) were measured in soils of later Pleistocene and Holocene age. Subsequently, data derived from laboratory investigations showed high electrical conductivities (mainly from high SO 4 2– ) and pH values as low as 3.9 in epipedons of Inceptisols and Spodosols. Proximity to coal-fired electrical generating stations and industrial activity in le Fayet and Sallanches (20 km to Northwest) may generate considerable output of SO 4 2– ions which, along with arsenic, antimony and bromine, survive transport up valley by anabatic wind systems. Because the country rock in the Chamonix area is largely an acidic crystalline complex of granite and gneiss, the tendency for lower pH's in the surface soils may have a disastrous effect on the coniferous forests in the area.

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Abstract  

As analytical techniques have become more sensitive, the role of trace elements associated with biological macromolecules has become the subject of many studies in the past twenty years. Many biologically significant macromolecules, such as nucleic acids and proteins, have trace elements essential to their function and structure. Instrumental neutron activation analysis (INAA) contributes useful information in such studies. A procedure combining polyacrylamide gel electrophoresis (PAGE) with INAA and autoradiography has been developed to study biological macromolecules and their associated trace elements. Results from the application of this method to several metalloproteins are presented.

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Abstract  

For more than a decade, archaeometrists have been analyzing archaeologically recovered human bones in an attempt to relate their trace element contents to diet. Although the problems of diagenesis have been recognized, the variable effects have been difficult to establish. In this paper, an assessment is made of the analytical reliability of the INAA determination of major and trace elements, using their short-lived radioisotopes in both regular and defatted modern cancellous bone, and in modern cortical bone. This modern bone information is then compared with analytical data for bones from Egyptian mummies ranging in age from 2000 to 3700 BP, and with normallyburied 11 th century French bones. Diagenetic effects may readily be detected by the measurement of elevated quantities of V, Mn, and Al in soil-contaminated bones. The Ca to P concentration ratios and the organic content may also be used to separate bone from diagenetically altered archaeological specimens.

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