Bronze Age Kfar Monash. Palestine – A Chemical and Lead Isotope Study into the Provenance of its Copper

Copper artefacts from the Palestinian EB I/ II Kfar Monash hoard are made of two distinct types of metal. Adzes, a spearhead and a long, curved knife consist of arsenic-and nickel-rich copper, with arsenic contents between 0.4% and 3.88% and an average As/ Ni ratio of 1.4. All other implements, weapons and also the enigmatic thin metal sheets (mean thickness about half a millimeter) are very pure copper. The same grouping is also observed in the lead isotopy of the objects : 206Pb-normalized abundance ratios of the AsNi-rich copper form a tight cluster at 208Pb/ 206Pb≈ 2.061, 207Pb/ 206Pb≈ 0.829 and 204Pb/ 206Pb≈ 0.0528 ; objects made of pure copper show a wide variation in abundance ratios which are much higher ; 208Pb/ 206Pb, e. g., varies between 2.09 and 2.12. For the AsNi-rich copper the trace element and lead isotope evidence points to the north (Eastern Anatolia) as source region although at present no specifi c ore deposit can be identified to have served for smelting this metal. For the pure copper there is an overabundance of possible sources at Faynan and a number of copper deposits in the Southern Sinai. Because of the absence from this copper of any useful tracer element the chemical data cannot contribute to the assignment of the metal to any source ores. The identification of potential ore sources does not yield any information as to where the artefacts might have been manufactured. Thus, cultural affinities with Egypt/ Nubia of the Kfar Monash objects can neither be confirmed nor refuted by material data as presented here.Les objets de cuivre du trésor de Kfar Monash (EB I/ II de Palestine) sont faits de deux types de métaux. Des herminettes, une pointe de lance et un long couteau recourbé sont composés d’un cuivre arsénique, riche en nickel, contenant entre 0,4 et 3,88 % d’arsenic et un rapport moyen de As/ Ni de 1.4. Les autres outils et armes, mais aussi les fi nes et énigmatiques feuilles métalliques, (épaisses d’environ 0,5 mm) sont en cuivre pur. La même partition se retrouve dans l’isotopie du plomb : la proportion du 206Pb pour les objets de cuivre riche en As/ Ni forme un cluster de 208Pb/ 206Pb≈ 2.061, 207Pb/ 206Pb≈ 0.829 et 204Pb/ 206Pb≈ 0.0528 ; en revanche, les objets en cuivre pur montrent une grande variation dans les proportions les plus élevées ; ainsi, par exemple le rapport 208Pb/ 206Pb varie entre 2,09 et 2,12. Concernant le cuivre riche en AsNi, les éléments traces et l’isotopie du plomb suggèrent que la source d’origine serait située au nord (Anatolie orientale) mais actuellement aucun gisement précis n’a été reconnu. Pour le cuivre pur, les sources possibles sont nombreuses dans le wadi Faynan et dans le sud du Sinaï. En l’absence de marqueurs spécifi ques, les données ne permettent pas d’identifi er une source du minerai. L’identifi cation des sources potentielles de ce minerai ne révèle aucune information sur le lieu de fabrication des objets. Les affi nités culturelles des objets de Kfar Monash avec l’Égypte et la Nubie ne peuvent donc être ni confi rmées ni infi rmées par les données matérielles présentées ici.Hauptmann Andreas, Schmitt-Strecker Sigrid, Begemann Friedrich. Bronze Age Kfar Monash. Palestine – A Chemical and Lead Isotope Study into the Provenance of its Copper . In: Paléorient, 2011, vol. 37, n°2. pp. 65-78

S-process krypton of variable isotopic composition in the Murchison meteorite

Current theories on the origin of the chemical elements explain the abundance of medium-heavy and heavy nuclides to be due to the capture by pre-existing lighter nuclides of free neutrons on either a slow timescale (s-process) or a rapid timescale (r-process). Experimental evidence in support of these theories comes from the analysis of carbonaceous chondrites. In acid-resistant residues of these meteorites a kind of xenon has been found, the isotopic composition of which matches almost perfectly that predicted for s-process xenon. We report data that allow us, for the first time, to derive with reasonable precision the full isotopic spectrum of s-process krypton as well. We show that this s-Kr in a residue from Murchison meteorite did not originate in one single s-process but rather is a mixture of contributions from stellar environments where the density of free neutrons was not the same. The astrophysical conditions under which this krypton has been produced were distinct from those that have been invoked to explain the Solar System s-process abundance. Similar to the ^(13)C-rich carbon component in an aliquot of the same residue, the s-process Kr from different astrophysical sites has retained its identity during the accumulation and subsequent history of the meteorite

Chemical Composition and Lead Isotopy of Metal Objects from the "Royal" Tomb and Other Related Finds at Arslantepe, Eastern Anatolia

We report on Late Chalcolithic and Early Bronze Age metal artefacts, slags and ores from the urban settlement of Arslantepe. Most of the artefacts analysed were found in the "royal" tomb, level VI B1, dating to the beginning of the Early Bronze Age I, and a few belong to the "palace board" from the temple building, level VI A, attributed to Late Uruk. Slags and ores come from different loci and levels. The metals can be classified into (arsenical) copper, arsenical copper high in nickel, silver, lead, and a new type of a silver-copper alloy. Tin bronze objects were not among the retrieved artefacts. Based upon lead isotope analyses we suggest that the silver-copper objects were produced by intentional mixing of the two metals, and, hence, provide the earliest evidence for alloying practices in eastern Anatolia. To bring out the bright silvery colour of the objects, the technique of depletion gilding was applied. Weapons from the "royal" tomb and from the "palace hoard" were made of arsenical copper. Lead isotope analyses lend support to previous archaeological suggestions that they were imported from Transcaucasia. Metal objects found at Early Bronze Age Arslantepe were partly produced on site from imported ores, and partly imported as finished objects. They probably represent two levels of trade : exchange of goods on the market, and high-level gift giving among social elites.Cet article traite d'objets en métal, de scories et de minerais provenant du centre urbain ď Arslantepe. La majorité des objets analysés ont été trouvés dans la tombe « royale » niveau VI В1 (début du Bronze ancien I), quelques autres appartiennent au trésor palatial du temple niveau VI A (Uruk récent). Les scories et les minerais proviennent de différents loci et niveaux. Les métaux peuvent être classés en cuivre (arsénieux), cuivre arsénieux à haute teneur en nickel, argent, plomb et en un nouveau type d'alliage argent-cuivre. Des artefacts en bronze stannifère n'apparaissent pas parmi les objets retrouvés. En nous fondant sur les analyses des isotopes du plomb, nous suggérons que les objets argent-cuivre résultent du mélange intentionnel de deux métaux, et apportent donc ainsi la plus ancienne preuve des pratiques d'alliage en Anatolie orientale. Pour produire la couleur argent vif de ces objets, la technique de réduction de la dorure (gilty depletion) fut utilisée. Les armes de la tombe « royale » et du trésor palatial, sont en cuivre arsénieux. Ces analyses isotopiques du plomb tendent à confirmer les suggestions, déjà émises sur le plan archéologique, qu 'elles étaient importées de Transcaucasie. Les objets en métal trouvés à Arslantepe (Bronze ancien) étaient en partie produits sur le site à partir de minerais importés, et en partie importés comme produits finis. Ils représentent donc probablement un système commercial à deux niveaux : un échange de produits sur le marché, et un niveau élevé du don-échange parmi les élites.Hauptmann Andreas, Schmitt-Strecker Sigrid, Begemann Friedrich, Palmieri A. Chemical Composition and Lead Isotopy of Metal Objects from the "Royal" Tomb and Other Related Finds at Arslantepe, Eastern Anatolia. In: Paléorient, 2002, vol. 28, n°2. pp. 43-69

Application de la methode du RaD a la mesure de l'age "chimique" d'un minerai d'Uranium

The RaD method suggested by F. G. Houtermans for the determination of the "chemical" age of uranium minerals consists in the measurement of Pb/U, from the ratio RaD/Pb. Since RaD is an isotope of lead, this ratio can be determined on any quantity of lead from the mineral. In this way the quantitative analyses of uranium and lead are avoided. The determination can be carried out on an extremely small quantity of matter. The conditions under which the method is applicable, and the ways of measuring RaD, are discussed. A confirmation has been obtained with two samples of pitchblende from Shinkolobwe: the ratio Pb/U was determined on the one hand by chemical analysis, and on the other by the RaD method. All the measurements of the two methods were carried out independently at the second Physical Institute of the University of Gottingen, and at the Centre de Physique Nucléaire de l'Université Libre de Bruxelles. One method of lead determination by dithizone extraction and polarography is described in detail. The technique of measuring the RaD by counting the beta particles of RaE was perfected. The ratios Pb/U determined by the two methods agree within the experimental errors. The advantages of the RaD method are summarized in the conclusion. © 1953.SCOPUS: ar.jinfo:eu-repo/semantics/publishe