Ronald G. V. Hancock

Mineralogical and chemical interactions of soils eaten by chimpanzees of the Mahale mountains and Gombe stream National Parks, Tanzania

Termite mound soils eaten by chimpanzees of the Mahale Mountains and Gombe National Parks, Tanzania, have mineralogical and geochemical compositions similar to many soils eaten by higher primates, but release very low levels of either toxic or nutritional inorganic elements to solution at acid pH. Comparison with control (uneaten) soils from the same areas showed lower levels of carbon and nitrogen in the eaten soils, a relationship confirmed by surface analysis. Surface analysis also revealed lower levels of iron on particle surfaces versus interiors, and higher levels of iron on ingested versus control soil particle surfaces. The soils can adsorb dietary toxins, present in the plant diet or those produced by microorganisms. Taking the toxic alkaloids quinine, atropine, sparteine, and lupanine as examples, it is evident that soils from Mahale have a very good adsorptive capacity. A new adaptive advantage of geophagy is proposed, based on the prevention of iron uptake. The behavior of the soils in vitro is consistent with the theory that geophagy has a therapeutic value for these chimpanzees.

Assessment of teeth as biomarkers for skeletal fluoride exposure

Skeletal fluorosis and dental fluorosis are diseases related to fluoride (F) ingestion. Bone is the largest storage site of F in our body. Therefore, bone F concentrations are considered biomarkers for total F body burden (exposure). However, difficult accessibility limits its use as a biomarker. Thus, a more accessible tissue should be considered and analyzed as a biomarker for total F body burden. The objective of this study, which was divided into two parts, was to evaluate teeth as a biomarker for skeletal F exposure. In part 1 of the study, 70 mice of three different strains (SWR/J, A/J and 129P3/J) were exposed to different levels of water fluoridation (0, 25, 50 and 100xa0ppm). Bone (femora and vertebrae) and teeth from these mice were then analyzed for F concentration using Instrumental Neutron Activation Analysis (INAA). In part 2 of the study, human teeth (enamel and dentin) and bone from 30 study subjects were collected and analyzed for F concentration using INAA. Study subjects lived in areas with optimum levels of water fluoridation (0.7 and 1xa0ppm) and underwent therapeutic extraction of their unerupted third molars. The values of bone and teeth F concentration were correlated for parts 1 and 2 of this study. The results showed that in the animal model, where animals were exposed to a wide range of F in their drinking water, tooth [F] correlated with bone [F]. However, no correlation was seen between bone and enamel F concentrations or between bone and dentin F concentrations in the human samples. Therefore, teeth are not good biomarkers for skeletal F exposure in humans when exposure is confined to optimum levels of F in the drinking water.

Middle-Holocene timberline fuctuation: influence on the genesis of Podzols (Spodosols), Norra Storfjället Massif, northern Sweden

Fluctuations of the altitudinal position and composition of the timberline in northern Sweden have occurred in response to climatic changes following deglaciation (c. 8800 yrs BP). In this study a soil sequence of predominantly Podzols (Spodosols) was analysed to determine if the soil profiles located above the present timberline were actively forming in the low-alpine environment, or whether they represent relict features of a once stronger pedogenic regime. The results of the soil analysis indicate a relatively uniform parent material with increasing fines near the surface reflecting aeolian influxed sediment. The soil profiles located above the timberline are generally characterized by darker colours, although with a lower accumulation of organic carbon and either similar or higher iron and aluminium in the spodic horizon than are found in the profiles located below the timberline. The alpine Podzols, generally located in protected swales, are quite distinct from Brunisols (Inceptisols) and Regosols (Entisols) found in slopes and swells on the predominantly undulating morainic and glaciofluvial landscape. This appears to indicate that Spodosols located above the present timberline are not actively being modified under the present low-alpine environmental conditions, but rather were initiated during the Atlantic Chronozone when a dwarf or stunted forest extended to approximately 900 m above sea level.

A rapid INAA method to characterize Egyptian ceramics

Abstract A rapid cost-effective instrumental neutron activation analysis method has been developed to characterize Egyptian ceramics. Using this approach, it is possible for one person to take representative samplings from 25 sherds, analyse them and tabulate the data within an 8 h working day. This in turn means that successive analytical samplings of available materials may be made on the basis of the suite of sherds already analysed. The efficacy of such an analytical procedure has been tested using a large number of sherds from the collection of the Egyptian Department of the Royal Ontario Museum. The results indicate that elements producing short-lived isotopes may be used to differentiate sherds made from Nile alluvium from sherds formed from chemically different clay sources and from mixtures of Nile alluvium and clays or other materials.

18TH CENTURY LEAD SMELTING IN CENTRAL NORTH AMERICA : EVIDENCE FROM LEAD ISOTOPE AND INAA MEASUREMENTS

Archaeological and historical studies suggest that metallic lead artefacts from early 18th century historic sites in the central United States were smelted from local ores. Direct confirmation of this can be obtained from lead isotope ratio measurements. The isotopic composition of leads from galena (PbS) deposits in south-east and central Missouri (SEM-CM) are different from those of ores from the upper Mississippi valley (UMV) in Iowa-Illinois-Wisconsin, and also from leads originating in north-western Europe. There is no evidence that smelting alters the isotopic ratios, so that the sources of metallic artefacts can also be determined. Samples of galena and lead recovered from four sites in Illinois (Kolmer, 11R50; Guebert, 11R1; Fox Encampment, MI-6; Newell Fort, near Starved Rock) were analysed. The isotopic data show that smelting of galena from the Missouri deposits began prior to 1730; UMV ores were being smelted prior to 1722. At least two sources of galena in SEM-CM were exploited, as distinguished by a combination of lead isotope and neutron activation analysis. Only one source in UMV appears to have been utilized. Metallic lead-rich artefacts of European origin, such as bale seals, musket balls, and pewter form a small fraction (~15%) of the artefact set. This is consistent with historic records which suggest that smelting of local galena began soon after the arrival of European colonists.

A hierarchical taxonomic procedure for provenance determination: A case study of Chalcolithic ceramics from the central Zagros

Abstract This study develops a data analysis methodology for the exploration of the variance in chemical composition of ceramic artifacts due to their typological, location and temporal characteristics. This methodology then allows for the characterization of ceramics based on these characteristics and the sequential assignment of unclassified ceramics to a region, subregion or site, with further assignment to specific ware and chronological period. The procedure uses INNA data on the elemental composition of ceramics in order to derive a series of classification functions for each category within each level of the taxonomic hierarchy. The developed procedure is used to investigate a provenance problem involving Chalcolithic ceramics from the Zagros region of western Iran. The results show that the elemental composition of ceramics, when coupled with multivariate statistical techniques, represents a powerful means for distinguishing ceramic provenance.

Petrographic analysis and INAA geochemistry of prehistoric ceramics from Robinson Pueblo, New Mexico

Abstract The examination of thin sections is a successful method for discovering provenance groupings of archaeological ceramics if non-clay inclusions in pottery paste can be identified with petrographically distinctive geologic sources. When this is not the case, geochemical analysis must be employed to search for more subtle evidence of such groupings. This situation is likely to arise in studies, such as the present one, where the objective is to discern local or subregional patterns of pottery manufacture and exchange. Ninety potsherds from site LA46326 in New Mexico were subjected to both INAA and petrographic analysis. The results of this conjoint approach are assessed in relation to geochemical theory and are analysed graphically and statistically.

Study of fines in bitumen extracted from oil sands by heat-centrifugation

Abstract The temperature dependence of, first, the yield of bitumen extracted from oil sands and, second, of the coextracted solid particles in the bitumen was studied. Centrifugal extractions were performed in an argon (inert) atmosphere at temperatures ranging from 30 °C to 150 °C. The co-extracted solid particles were investigated through digital image analysis, instrumental neutron activation analysis and ash yield. The yield of bitumen increases with extracting temperature and is also dependent on the grade and origin of the oil sand. The quantity of fines, e.g. clay minerals or fine sand particles is dependent on the grade and origin of the oil sand. The total amount of co-extracted solid particles is found to be independent of the extracting temperature.