Indigenous Iron Research Articles

Roman horticulture beyond the frontier: garden cultivation at Iron Age Uppåkra (Sweden)

Traditionally, the study of Roman cultural imports to Roman Iron Age societies in Scandinavia has been based on analysis of the artefactual record. The starting point has been artefacts held to be high-status objects deriving chiefly from funerary contexts and, to a lesser degree, from settlement sites. Although the existing evidence at Uppåkra, a high-status settlement site in Scania province, Sweden, comes only from residential contexts, we will address the ongoing debate concerning Roman cultural imports with ecofactual evidence, to consider which aspects of Roman culture were introduced, which parts of Roman society were mediators, and the underlying social reasons for the introduction of the archaeobotanical remains into indigenous Iron Age society.

Comparative study on simultaneous leaching of nutrients during bioleaching of heavy metals from sewage sludge using indigenous iron and sulphur oxidising microorganisms

The present study investigated the changes in nutrient profile of sewage sludge during bioleaching in a batch mode of operation. The study identified the optimum bioleaching period at which maximum solubilisation of metals is achieved while maintaining the fertilising property of the bioleached sludge. The bioleaching experiments were performed using anaerobically digested sewage sludge by employing indigenous iron and sulphur oxidising microorganisms. The results showed that bioleaching using sulphur oxidising microorganisms is comparatively advantageous due to the higher solubilisation of heavy metals. However, despite its high potential in solubilisation of heavy metals from the sludge, the bioleaching process resulted in the undesirable dissolution/loss of sludge bound nutrients (nitrogen and phosphorus), thus making the sludge less attractive for land application as a fertiliser. After 16 days of bioleaching about 45% of the nitrogen and 34% of the phosphorus were leached from the sludge using indigenous iron oxidising microorganisms, whereas about 78% of the nitrogen and 56% of the phosphorus were leached using indigenous sulphur oxidising microorganisms. The findings indicated that the fertilising property of the sewage sludge can be maintained by conducting the process for a shorter duration of time (up to 10 days). The optimum bioleaching period was 10 days where about 85%Cu, 71%Ni, 91%Zn and 61%Cr were solubilised from the sludge while the loss of nitrogen and phosphorus was only 56 and 51% respectively, by using sulphur oxidising microorganisms. The heavy metals remaining in the bioleached sludge were mostly in the residual fraction ensuring the safe disposal of bioleached sludge for land application as a fertiliser.Cette étude examine les changements du profil de nutriment de boues d’épuration lors de la biolixiviation d’un procédé discontinu. L’étude identifie la durée optimale de biolixiviation à laquelle la solubilisation maximale des métaux est achevée tout en maintenant les propriétés fertilisantes de la boue biolixiviée. On a effectué les expériences de biolixiviation en utilisant des boues d’épuration digérées en condition anaérobique et en employant l’oxydation par ferro- ou thiomicroorganismes indigènes. Les résultats ont montré que la biolixiviation par oxydation avec des thiomicroorganismes était comparativement avantageuse grâce à la solubilisation plus élevée des métaux lourds. Cependant, en dépit de son potentiel élevé de solubilisation des métaux lourds de la boue, le procédé de biolixiviation avait pour résultat une dissolution ou une perte indésirables des nutriments liés dans la boue (azote et phosphore), rendant ainsi la boue moins attrayante pour application dans les champs comme engrais. Après 16 jours de biolixiviation, environ 45% de l’azote et 34% du phosphore étaient lixiviés de la boue par oxydation avec des ferromicroorganismes indigènes, alors qu’environ 78% de l’azote et 56% du phosphore étaient lixiviés en utilisant des thiomicroorganismes indigènes. Les constatations indiquent qu’on peut maintenir les propriétés fertilisantes de la boue d’épuration en effectuant le processus sur une durée plus courte (jusqu’à 10 jours). La période optimale de biolixiviation était de 10 jours, pendant lesquels environ 85% du Cu, 71% du Ni, 91% du Zn et 61% du Cr étaient solubilisés à partir de la boue alors que les pertes d’azote et de phosphore étaient seulement de 56% et de 51%, respectivement, en utilisant les thiomicroorganismes. Les métaux lourds qui restaient dans la boue biolixiviée se trouvaient principalement dans la fraction résiduelle, assurant la disposition sécuritaire comme engrais de la boue biolixiviée.

Breakthrough studies with mono-, binary- and ternary-ion systems comprised of Fe(II), F− and As(III) using river sand packed columns for groundwater treatment

Groundwater in Assam, India, contains excessive amounts of arsenic (As(III)), fluoride (F(-)) and iron (Fe(II)). The rural and semi-urban population of Assam uses indigenous iron filters fabricated using processed sand (PS) as one of the chief constituents to reduce Fe(II) concentration; however, no efforts have been made to reduce As(III) or F(-) concentrations before use. The present work is directed towards assessing the potential of PS for removal of these ions from mono-, binary- and ternary-ion systems through continuous mode column studies. Synthetic water samples containing fixed concentration of ions were prepared using deionized water. The observed order of breakthrough of ions was: As(III) followed by Fe(II) and F(-) followed by Fe(II) in the case of the binary ion systems of Fe(II) + As(III) and Fe(II) + F(-). The throughput volume for As(III) in the (Fe(II) + As(III)) system and for F(-) in the (Fe(II) + F(-)) system is termed the critical breakthrough throughput volume. In the ternary ion system (Fe(II) + As(III) + F(-)), the order of breakthrough of ions observed was F(-), then As(III) and then Fe(II) and hence the throughput volume F(-) is termed the critical breakthrough throughput volume. Results of column studies also indicate the impact on the uptake of the selected ion by the presence of the other ion present in the binary- and ternary-ion systems.

Towards a resuscitation of indigenous iron technology among the Igede of central Nigeria

Indigenous iron working was the only means by which the Igede of central Nigeria sourced their various kinds of iron objects, which served as farming implements and weapons for hunting or battle in pre-colonial times. However, with the commencement of colonial activities in the area, there was a gradual shift of emphasis from locally made iron objects to those that were traded into the area from outside. This shift continued steadily and has so far culminated in a complete neglect of the practice in contemporary times. Consequently, relics abound in many parts of Igede as evidence of extensive indigenous iron working that took place in such places in the past. This article provides a close examination of the point at which the practice actually began to decline, and the factors that were principally responsible for the decline. In the end, pragmatic suggestions are advanced on ways of reviving the practice, not only as a way of restoring an invaluable aspect of the people's cultural heritage, but also as a way of enhancing the local economy of the people.

Potential of community prepared wooden charcoal of Assam (India) for As(III) removal through batch and continuous column studies

Groundwater is the main source of domestic water for the rural population of Assam, India, which contains arsenic (As(III)) in the range 50–200 μg L−1. The people use variants of indigenous household iron filter units fabricated using community prepared wooden charcoal (CPWC) as one of the filtering medium to remove excess concentration of Fe(II), but no efforts are made to reduce As(III) levels. The present work evaluates the potential of CPWC for As(III) removal through batch and continuous column studies. The As(III) uptake appears to be rapid in the first 60 min, and achieves equilibrium by 180 min. The pseudo-second-order kinetic model best describes the experimental kinetics data. The Freundlich isotherm represents the equilibrium data. The continuous column studies yield decreased volume of treated water at breakthrough with increase in flow rates, whereas the volume of treated water increases with increase in bed depth. The error between predicted and experimental values of service time varies between 0.28 and 21.85%. The study indicates significant potential of CPWC for As(III) removal.

Influence of indigenous and added iron on copper extraction from soil

Experimental tests of copper leaching from a low permeability soil are presented and discussed. The objective of the experiments was to investigate the influence of indigenous and added iron in the soil towards copper mobilization. Metals’ leaching was performed by flushing (column tests) or washing (batch tests) the soil with an aqueous solution of ethylenediaminetetraacetic acid, EDTA. An excess of EDTA was used in flushing tests (up to a EDTA:Cu molar ratio of about 26.2:1), while, in washing tests, the investigated EDTA vs. copper molar ratios were in the range between 1 (equimolar tests) and 8. Copper extraction yield in flushing tests (up to about 85%) was found to depend upon contact time between the soil and the leaching solution and the characteristics of the conditioning solution. The saturation of the soil with a NaNO 3 solution before the treatment, favoured the flushing process reducing the time of percolation, but resulted in a lower metal extraction during the following percolation of EDTA. The indigenous iron was competitive with copper to form EDTA complexes only when it was present in the organic and oxides–hydroxides fractions. Artificial iron addition to the soil resulted in an increase of both the exchangeable iron and the iron bonded to the organic fraction of the soil, thus increasing the overall amount of iron available to extraction. In both batch and continuous tests, the mechanism of copper extraction was found to involve the former dissolution of metal salts, that lead to an initial high concentration of both copper and selected competitive cations (essentially Ca 2+), and the following EDTA exchange reaction between calcium and copper complexes. The initial metal salts dissolution was found to be pH-dependant.

Mineralogical Characterization of Dilband Iron Ore Deposits of Balochistan, Pakistan

Dilband iron ore deposits, recently discovered in 1997 by Geological Survey of Pakistan (GSP) in Kalat Division Balochistan, Pakistan, is of major importance from a socio-economical point of view among the indigenous iron ore deposits discovered so far in Pakistan. In order to meet the requirements of Pakistan Steel Mills ore specification (i.e. 57–60 % Fe (min), 8.5 % SiO2 (max), 0.5 % Al2O3 (max), 0.1 %P (max), and 0.05 % S), the ore requires an adequate concentration method. This calls for detailed characterization of process relevant minerals and their intergrowth. For this reason mineralogical, petrographic, and elemental analysis were performed using XRD, thin section and SEM with EDS, and XRF and Atomic Absorption Spectrometer techniques, respectively. Mineralogical study revealed that Dilband iron ore is mainly composed of 46.27 % hematite, 17.41 % quartz 14.47 % calcite, 9.24 % chlinochlore, 10.5 % kaolinite, and 1.75 % fluorapatite minerals. Atomic absorption analysis of different size fractions ranging from −600 µm down to −38 µm indicated that Dilband iron ore contains on average of 40.18 % Fe, 18.34 % SiO2, 5.32 % Ca, and 2.262 % Al. Whereas average analysis of different size fractions on XRF indicated 44.3 % Fe, 20.4 % SiO2, 8.8 % CaO, 6.35 % Al2O3, 1.08 % P2O5, and 0.065 % SO3. Three types of iron stones namely hematiteooides, hematite-peloids, and hematite biosparite were identified from petrographic study. From the mineralogical and elemental analysis data finely dissemination of impurities specially quartz, alumina and phosphorous in hematite phase is conceived, suggesting that Dilband iron ore is not amenable to upgrade with conventional techniques.

Removal of Chromium (VI) by Acid-Washed Zero-Valent Iron under Various Groundwater Geochemistry Conditions

The hexavalent chromium (Cr(VI)) removal capacity of acid-washed zerovalent iron (AW-Fe0) was evaluated under different groundwater geochemistry conditions through column experiments. It was found that each gram of the AW-Fe0 could remove 0.65-1.76 mg of Cr(VI) from synthetic groundwater in the absence of bicarbonate (HCO3-), magnesium and/or calcium ions. Groundwater geochemistry was found to exert various degrees of impact on Cr(VI) removal by the AW-Fe0, in which HCO3- alone gave the mildest impact whereas the copresence of calcium and HCO3- exerted the greatest impact In comparison with the unwashed Fe0, the AW-Fe0 showed a poorer Cr(VI) removal capacity and was also more susceptible to the influence of the dissolved groundwater constituents on Cr(VI) removal,thereby indicating the unsuitability of using AW-Fe0 in permeable reactive barriers for remediation of Cr(VI)-contaminated groundwater. On the AW-Fe0 surface, where the indigenous iron precipitates were almost erased, trivalent chromium including chromium (III) oxides, hydroxides, and oxyhydroxides in irregular strip, chick footmark-liked or boulder-liked forms as well as Cr(III)-Cr(VI) mixed oxides were detected.

Metals in society

Indigenous iron working has received considerable attention from Africanist archaeologists but its contribution to the evolution of political process has never attracted serious interest in southern Africa. In this article, comparative historical and archaeological data presented suggest that specialist iron working was linked with the configuration and reconfiguration of political and economic systems. This is because iron was produced within a worldview and the ideological and symbolic meanings attached to its production and use sometimes fashioned opportunities through which power was created, negotiated and institutionalized. A number of examples from southern Africa are discussed and serve to illustrate these points.

Iron smelting in pre-colonial Zimbabwe: Evidence for diachronic change from Swart village and Baranda, northern Zimbabwe

In conventional reconstructions of southern African archaeology, the production of iron has been seen as unchanging for the last 2000 years. Significantly, this contrasts with the changes that have been noted in broader society and other classes of material culture of the same period. Despite iron being used as a chronostratigraphic indicator, virtually nothing is known on the patterns of iron production within the Iron Age and whether change in technology and the socio-cultural context of production took place. From a combined archaeological and metallurgical perspective, the historical development of iron working has never been explored. For example, it is not known whether similar types of furnaces were constantly operated throughout the last two millennia. Excavations at two sites in northern Zimbabwe, one Gokomere-Ziwa (800 - 1200 cal AD) and one Zimbabwe tradition (1500 - 1700 cal AD), have shown differences in iron pyrometallurgical debris, tentatively suggesting that they represent separate metal working practices. By comparing the archaeological and metallurgical evidence from the two sites, this paper represents an initial step in delineating patterns of indigenous iron production in one region of Zimbabwe.

Removal of Cr from tannery sludge by bioleaching method

Bioleaching of Cr(III) from tannery sludge using the mixture of ingenuous iron-and sulfur-oxidizing bacteria was investigated in batch flasks. Experiments involved the adaptation of indigenous iron- and sulfur-oxidizing bacteria, the pre-acidification the sludge to pH 6.0 and the addition of energy substrates. Results showed the inoculation of mixture of ingenuous iron- and sulfur-oxidizing bacteria and co-addition of Fe 2+ and elemental sulfur accelerated acid production and increase of oxidation-reduction potential originating from the bio-oxidation of Fe 2+ and elemental sulfur. Dissolved Cr concentration increased concomitant with pH decreased in the sludge and reached its maximum removal of 95.6%. The amelioration of the odor of bioleached sludge could be noted. However, 20.4% of N, 24.5% of P and 14.3% of organic matter were lost in the bioleaching process. The residual Cr content in the leached tannery sludge was acceptable for use in agriculture. This study had shown the feasibility of applying the bioleaching process, developed for sewage sludge, to tannery sludge with high Cr.

Kinetics of Bacterial As(III) Oxidation and Subsequent As(V) Removal by Sorption onto Biogenic Manganese Oxides during Groundwater Treatment

In groundwaters, indigenous iron- and manganese-oxidizing bacteria are able to catalyze the oxidation of dissolved manganese [Mn(II)], which can subsequently be removed by filtration of the insoluble products (hydrous manganese oxides). This process results in the creation of a natural coating on the surface of the filter medium, and if arsenic is simultaneously present in the groundwater, it can subsequently be removed by sorption. The results indicate that this method can serve as an alternative treatment option for the removal of low-level arsenic concentrations [35 and 42 μg/L for As(III) and As(V), respectively]. Rapid oxidation of As(III) was observed prior to removal by sorption onto the biogenic manganese oxide surfaces. The rates of As(III) oxidation were estimated, yielding an apparent first-order constant of 0.23 min-1 (half-life of 3 min). A comparison of these values with the respective data obtained from the literature indicated that the rate of oxidation of As(III) was significantly higher than the rates reported for abiotic As(III) oxidation by manganese oxides, supporting the indication that bacteria play an important role in both the oxidation of As(III) and the generation of reactive manganese oxide surfaces for the removal of As(III) and As(V) from solution. The following sequence of reactions have been found to occur in the treatment system: (a) oxidation of Mn(II) to Mn(IV) and Fe(II) to Fe(III), (b) oxidation of As(III) to As(V), (c) precipitation of manganese(IV) oxides, (d) abiotic oxidation of As(III) by manganese(IV) oxides, and (e) As(V) sorption by manganese(IV) oxides, where steps a and b are biotic and steps c−e are abiotic. The presence of phosphates at concentrations of around 600 μg/L had an adverse effect on As(III) removal (competitive adsorption), reducing the overall removal efficiency by 50% (from 80 to 30%), although it did not affect the oxidation of As(III).

The Return of the Native

The Return of the Native

Oxidation of H2S by iron oxides in unsaturated conditions.

Previous studies have demonstrated that gas-phase H2S can immobilize certain redox-sensitive contaminants (e.g., Cr, U, Tc) in vadose zone environments. A key issue for effective and efficient delivery of H2S in these environments is the reactivity of the gas with indigenous iron oxides. To elucidate the factors that control the transport of H2S in the vadose zone, laboratory column experiments were conducted to identify reaction mechanisms and measure rates of H2S oxidation by iron oxide-coated sands using several carrier gas compositions (N2, air, and O2) and flow rates. Most experiments were conducted using ferrihydrite-coated sand. Additional studies were conducted with goethite- and hematite-coated sand and a natural sediment. Selective extractions were conducted at the end of each column experiment to determine the mass balance of the reaction products. XPS was used to confirm the presence of the reaction products. For column experiments in which ferrihydrite-coated sand was the substrate and N2 was the carrier gas, the major H2S oxidation products were FeS and elemental sulfur (mostly S8(0), represented as S(0) for simplicity) at ratios that were consistent with the stoichiometry of the postulated reactions. When air or O2 were used as the carrier gas, S(0) became the dominant reaction product along with FeS2 and smaller amounts of FeS, sulfate, and thiosulfate. A mathematical model of reactive transport was used to test the hypothesis that S(0) forming on the iron oxide surfaces reduces access of H2S to the reactive surface. Several conceptual models were assessed in the context of the postulated reactions with the final model based on a linear surface poisoning model and fitted reaction rates. These results indicate that carrier gas selection is a critical consideration with significant tradeoffs for remediation objectives.

Stanford University Excavations on the Acropolis of Monte Polizzo, Sicily, I: Preliminary Report on the 2000 Season

M onte Polizzo is a hilltop site 6 km northwest of Salemi, in Trapani province, western Sicily (370 56' N, 120 46' E; fig. 1). The highest point on the acropolis is 725.9 m above sea level, and the view from the summit takes in most of western Sicily, including Segesta and Mozia, 9 km and 28 km distant respectively. Since the 1950s Monte Polizzo has been designated a forest preserve, and extensively planted with oak and pine. Artifacts from the site have been known since the nineteenth century. Vincenzo Tusa, then Soprintendente of Archaeology for the Palermo region, carried out the first systematic excavations in 1970. He examined three areas centro abitato, alla sommita del monte, distante tra loro almeno trecento metri. 1 In all three, he found rectilinear buildings containing indigenous Iron Age and imported Greek pottery. Saggio IX uncovered a rectangular structure on the west slope of the acropolis. It had two phases of walls (fig. 2), and the finds included Corinthian, East Greek, and incised local wares, and a hoard of bronzes, now in the Palermo Museum. In 1996, Sebastiano Tusa, Soprintendente of Prehistoric Archaeology for the Trapani region, and Kristian Kristiansen, of the University of Goteborg, opened a new international study of the Monte Polizzo region, the Scandinavian-Sicilian Archaeological Project. This study subsequently expanded to involve teams and individuals from North America and the United Kingdom and now includes a wide range of interconnected archaeological projects. Our main goal is to explore the development of indigenous society in western Sicily in the sixth through fourth centuries B.C., when Greek and Carthaginian imperialism began seriously affecting the upland interior. We are interested in defining more precisely what is meant by Hellenization; the selective local adoption of and resistance to Punic and Greek material culture; the transformation of economic and class structures as the political environment changed; and the constitution of ethnic identities. In addition to these questions focusing on the Mediterranean region, Monte Polizzo is part of a larger comparative project on later

Inactivation of the plasma membrane ATPase of Schizosaccharomyces pombe by hydrogen peroxide and by the Fenton reagent (Fe2+/H2O2): nonradical vs. radical-induced oxidation.

In the absence of added Fe2+, the ATPase activity of isolated Schizosaccharomyces pombe plasma membranes (5-7 mumol P(i) per mg protein per min) is moderately inhibited by H2O2 in a concentration-dependent manner. Sizable inactivation occurs only at 50-80 mmol/L H2O2. The process, probably a direct oxidative action of H2O2 on the enzyme, is not induced by the indigenous membrane-bound iron (19.3 nmol/mg membrane protein), is not affected by the radical scavengers mannitol and Tris, and involves a decrease of both the K(m) of the enzyme for ATP and the V of ATP splitting. On exposing the membranes to the Fenton reagent (50 mumol/L Fe2+ + 20 mmol/L H2O2), which causes a fast production of HO. radicals, the ATPase is 50-60% inactivated and 90% of added Fe2+ is oxidized to Fe3+ within 1 min. The inactivation occurs only when Fe2+ is added before H2O2 and can thus bind to the membranes. The lack of effect of radical scavengers (mannitol, Tris) indicates that HO. radicals produced in the bulk phase play no role in inactivation. Blockage of the inactivation by the iron chelator deferrioxamine implies that the process requires the presence of Fe2+ ions bound to binding sites on the enzyme molecules. Added catalase, which competes with Fe2+ for H2O2, slows down the inactivation but in some cases increases its total extent, probably due to the formation of the superoxide radical that gives rise to delayed HO. production.

Origin and properties of humus in the subsoil of irrigated rice paddies

To study the accumulation mechanism of dissolved organic carbon (DOC) leached from the plow layer soil in the subsoil of irrigated rice paddies, leaching experiments using a series of plow layer soil columns and subsoil columns were conducted. The binding types of organic matter in the subsoil columns were estimated by successive extraction of organic matter with water, Na2S04, Na4P2O7 (pH 7.0), Na4P2O7 + NaOH, and NaOH solutions. The ability of the subsoil constituents to adsorb DOC was investigated by removing them. Successive removal of indigenous organic matter and iron oxides and hydroxides from the subsoil samples decreased the adsorption of DOC to the subsoil column. The decrease appeared in the Na2S04- and Na4P207 (pH 7.0)-extractable fraction for the organic matter removed subsoil column (Org.(—) subsoil column) and in the Na4P2O7 (pH 7.0)-extractable fraction for the organic matter and iron oxides and hydroxides removed subsoil, column (Org. (—) \\d. Fe(—) subsoil column), respectively, suggesting the importance of polyvalent cations in the subsoil and in the leachate for binding DOC to the subsoil. The effect of drainage on the accumulation of DOC was investigated in the case three repetitions of leaching incubation followed by stand incubation with or without drainage. The sum of the amounts of DOC retained in the subsoil columns during the 3 periods of leaching incubation was larger in the treatment with drainage than in the treatment without drainage. Since the net increase in the total organic carbon content in the subsoil columns was less pronounced in the treatment with drainage than in the treatment without drainage (untreated subsoil columns), or similar between the two treatments (Org.(—) subsoil columns), the drainage was assumed to promote the adsorption of DOC to the subsoil, and also to promote organic matter decomposition. In the treatment with drainage, Na4P207 (pH 7.0)-extractable organic carbon mainly accumulated. Drainage also resulted in the impossibility of extracting water-extractable organic carbon with water, and promoted the formation of humin.

Comparison of pyrites varying in water-soluble sulfur with gypsum for the reclamation of alkali soils under a rice-wheat rotation

We evaluated the effect of agricultural-grade (AG) pyrites (total sulfur 22%) varying in water-soluble sulfur (1–8%) and gypsum on the soil properties and yields of rice and wheat in alkali soils during the years 1993–1995 at the Gudha and Saraswati experimental farms at the Central Soil Salinity Research Institute, Karnal, India. Gypsum and pyrites were applied on the basis of gypsum requirement (GR) of the soils. Results showed that the efficiency of AG pyrites in decreasing soil pH and exchangeable sodium percentage (ESP) and increasing crop yields was dependent on their water-soluble sulfur content at the time of application to the field. Pyrites with 5.5% and 8% soluble sulfur were as effective as gypsum. The freshly mined pyrite (water-soluble S 1%) was found to be inefficient in reclaiming alkali soils. We also explored the possibility of increasing the water-soluble sulfur content of pyrite by optimizing its storage conditions. When pyrite (1% water-soluble S) was stored under moist conditions by sprinkling water over the bags under a rain shelter, there was an enrichment of indigenous iron- and sulfur-oxidizing bacteria of pyrite, and the water-soluble sulfur increased to 5% within a period of 6 months. However no such increase occurred when pyrite was stored dry. We conclude that the soluble sulfur content of pyrite increased during its storage under moist conditions and should be between 6% and 8% at the time of its application to the field.

Early Iron Age Metal Working at the Tsodilo Hills, Northwestern Botswana

This paper describes Early Iron Age metal working at the sites of Divuyu and Nqoma, excavated by James Denbow and Edwin Wilmsen, in northwestern Botswana. This research represents the first metallographic analysis of a large collection of Iron Age metal artefacts from southern Africa. The artefacts studied were small articles of copper and iron, mostly items of jewellery and tools possibly used in their manufacture. They were classified and sampled representatively for metallographic and chemical analysis. Fifty-four artefacts were studied in detail and the fabrication technology reconstructed. The forging, and possibly also smelting, of iron took place at both sites during the Early Iron Age. The primary smelted product was inhomogeneous iron and steel, with typical fayalitic slag, characteristic of indigenous bloomery iron production. Forging was carried out in an oxidizing hearth. The technique used was poor, with no evident control over carbon content or the mechanical properties of the steel, and with no heat treatment other than annealing. The fabrication of artefacts involved forging square wire and flat sheets, which were cut into strips for beads, clips, chains, and fibre-cored wound ornaments. Crude round iron wire was used to make numerous finger rings. Copper was worked similarly, usually leaving the metal in its annealed state. Significant chemical variation in the copper artefacts and iron slag inclusions showed that diverse ore sources were exploited. There were stylistic similarities between individual artefacts from these sites in the Tsodilo Hills and Early Iron Age material from Zaı̈re and the northern Transvaal. Comparison of the fabrication technology with Late Iron Age material suggests that local indigenous iron and copper working technology in southern Africa has changed little since its inception.

On the use of iron by the Eskimos in Greenland

Seventy-four iron objects were randomly selected from the archaeological items found in Greenland and have been stored in Copenhagen since about 1850. The objects consist of knives, ulos (knife used by Eskimo women for skinning), and harpoon blades, but also several nonworked fragments and some “hammerstones” were included. The objects were subjected to microscopical examination and x-ray microanalysis to determine their nature and mode of fabrication. The objects may be sorted into three groups. The majority of tools found north of Melville Bay were produced from small fragments of the Cape York iron meteorite shower that fell near Savigsivik over 2000 years ago. Half of the objects found in the Disko Bay area may be traced to occurrences of iron-bearing basalt, while the other half were produced from wrought iron. Some of these wrought-iron tools originated at Norse settlements and were apparently carried as far north as 77° by Norse ships as early as the 12th Century. Other wrought-iron tools were introduced by whalers, mainly of Dutch, Spanish and British origin, after about a.d. 1575. Some tools may derive from iron nails and hoops from wrecked ships. No signs of indigenous iron production have been detected.