LEAD ISOTOPE CHARACTERIZATION OF COPPER INGOTS FROM SARDINIA (ITALY): INFERENCES ON THEIR ORIGINS

The provenance of the materials making up the metal artifacts represents a fundamental question for archaeological research. The complex processes necessary to extract the metals from the minerals cause considerable changes in their chemical composition. By contrast, the ratio of the different lead isotopes in artifacts is not influenced by metallurgie processes. Therefore, the raw mineral material and the extracted metal exhibit the same isotope "footprint". Over the course of history, Sardinia has played a major role in maritime routes. Its considerably rich mineral resources, with copper, lead and iron mineralizations, moreover complemented its strategic importance. During the 10th and 9th centuries BC Sardinia, because of its strategic location, was to become directly involved in the "precolonial" Phoenician expansion. Two repositories of copper ingots recovered at different levels within a nuragic village in northwest Sardinia, can be placed within this historical context of intense traffic and exchange of goods between native Sardinian and Phoenician communities. The ingots were made in different shapes: plane-convex, biconvex, truncated cone and irregular. The analyzed ingots exhibit a considerable lead isotopie variability, although no systematic differences in isotope composition were revealed between the ingots from the two different repositories. Moreover, no systematic isotopie variations were observed between the different shapes in which the material was found. Overall, the ingots exhibit a linear distribution in the lead/lead diagrams. The group of ingots with the lowest isotope ratios project onto the area defined by the northwestern Sardinian mineralizations. The ingot located on the other extreme end of the straight line in the Pb diagrams overlaps the area defined by the southern Sardinian deposits. The isotope footprints of the intermediate samples seem to indicate that they stem from the mixing of two components from two different mining areas of Sardinia, one in the north, the other in the south. Therefore, widespread exchange of metal must have taken place throughout the island, and such an exchange does not seem to have been hindered by the advent of the Phoenicians in Sardinia. The results of the present investigation indicate that the majority of the examined ingots was produced with metal from the northwest of the island, and that these mines were therefore known and exploited in nuragic times. Such findings shed new light on the complex issues involved in proto-historic Sardinian metallurg

LEAD ISOTOPE CHARACTERIZATION OF COPPER INGOTS FROM SARDINIA (ITALY): INFERENCES ON THEIR ORIGINS

ABSTRACT The provenance of the materials making up the metal artifacts represents a fundamental question for archaeological research. The complex processes necessary to extract the metals from the minerals cause considerable changes in their chemical composition. By contrast, the ratio of the different lead isotopes in artifacts is not influenced by metallurgic processes. Therefore, the raw mineral material and the extracted metal exhibit the same isotope "footprint". Over the course of history, Sardinia has played a major role in maritime routes. Its considerably rich mineral resources, with copper, lead and iron mineralizations, moreover complemented its strategic importance. During the 10th and 9th centuries BC Sardinia, because of its strategic location, was to become directly involved in the "precolonial" Phoenician expansion. Two repositories of copper ingots recovered at different levels within a nuragic village in northwest Sardinia, can be placed within this historical context of intense traffic and exchange of goods between native Sardinian and Phoenician communities. The ingots were made in different shapes: plane-convex, biconvex, truncated cone and irregular. The analyzed ingots exhibit a considerable lead isotopic variability, although no systematic differences in isotope composition were revealed between the ingots from the two different repositories. Moreover, no systematic isotopic variations were observed between the different shapes in which the material was found. Overall, the ingots exhibit a linear distribution in the lead/lead diagrams. The group of ingots with the lowest isotope ratios project onto the area defined by the northwestern Sardinian mineralizations. The ingot located on the other extreme end of the straight line in the Pb diagrams overlaps the area defined by the southern Sardinian deposits. The isotope footprints of the intermediate samples seem to indicate that they stem from the mixing of two components from two different mining areas of Sardinia, one in the north, the other in the south. Therefore, widespread exchange of metal must have taken place throughout the island, and such an exchange does not seem to have been hindered by the advent of the Phoenicians in Sardinia. The results of the present investigation indicate that the majority of the examined ingots was produced with metal from the northwest of the island, and that these mines were therefore known and exploited in nuragic times. Such findings shed new light on the complex issues involved in proto-historic Sardinian metallurgy

Major, trace element and Sr-isotope characterization of the Samothraki tertiary volcanic rocks, NE Aegean

Tertiary volcanic rocks of the Samothraki Island were found to show a wide range of composition. Two series have been distinguished showing diverging trends both in major and in trace element diagrams. Sr-isotope data show even more pronounced grouping of the two series thus reinforcing the suggestion of diverse evolutionary processes. A possible origin from either an enriched mantle source for the old volcanic series and mantle plus crust for the young volcanic rock series is suggested. Fractional crystallization or any other closed system process cannot account for the geochemical and isotopie variations seen witin the rock series. More complex processes must be responsible for their evolution history

Pre-metamorphic melt infiltration in metasediments : geochemical, isotopic (Sr, Nd, and Pb), and field evidence from Serie dei Laghi (Southern Alps, Italy)

Gradual transitions from K-feldspar free gneisses to K-feldspar bearing augengneisses are sometimes observed in metamorphic terranes. They have been explained with metasomatic porphyroblastic growth connected with regional metamorphism, or with pre-metamorphic presence of magmatic megacrysts. A transition of this kind can be observed in the Serie dei Laghi (Southern Alps, Italy), where coarse-grained metaarenites (Cenerigneiss) grade into Ceneri augengneisses with large K-feldspar porphyroclasts, and banded amphibolites of the \u2018\u2018Strona Ceneri Border Zone\u2019\u2019 grade into Hbl augengneisses rich in K-feldspar. The Ceneri augengneisses are chemically indistinguishable from the Cenerigneiss, but have higher 87Sr=86Sr (0.7256\u20130.7258 vs. 0.7215\u20130.7233), similar to those of the Ordovician granites that were intruded, before the regional metamorphism, into the protoliths of both Cenerigneiss and amphibolites. The Cenerigneiss contains two types of zircons: (1) highly luminescent, rounded grains or fragments, yielding U\u2013Pb SHRIMP ages from 0.43 to 1.0 Ga; (2) euhedral grains with oscillatory zoning (magmatic), with U\u2013Pb SHRIMP concordant ages of 466 13 Ma. This age coincides with the Rb\u2013Sr whole rock emplacement age of the Ordovician granitoids (466 5Ma).The Hbl augengneisses form three groups with distinct geochemical patterns, whose distributions on inter-element diagrams trend towards the Ordovician metagranites and meta-aplites. In addition, the Hbl augengneisses have higher 87Sr=86Sr (0.7132\u20130.7147 vs. 0.7031\u20130.7046) and lower 143Nd=144Nd (0.51214\u20130.51219 vs. 0.51273\u20130.51297) than the amphibolites, suggesting the addition of an isotopically evolved component. The observed chemical and isotope patterns, as well as the vicinity of the augen gneisses to the Ordovician intrusions, lead us to conclude that the Ceneri augengneisses and Hbl augengneisses are the result of infiltration of residual hydrous magmas into the protolith of both the Cenerigneiss and the amphibolites at the time of Ordovician granite emplacement, long before the regional metamorphism in the Serie dei Laghi

Comportamento, produção e qualidade do leite de vacas Holandês-Gir com climatização no curral

This study was conducted with the objective to evaluate the duration of exposure of animals to the evaporative cooling system in the waiting barn on the weather variables (temperature and relative humidity), animal behavior, production and quality aspects of milk from Girolando cows. Sixteen multiparous lactating cows were used having a genetic composition of 7/8 Holstein-Gir and mean milk production of 18 kg animal-1day-1. A 4 × 4 Latin square design was used. The experiment was conducted during the summer season (February-March 2009) and lasted 56 days. The treatments consisted of different periods of 10, 20 and 30 minutes of exposure to acclimatization and control. Time of 30 minutes of exposure to thermal conditioning system enabled the second milking (evening shift), providing an increase in milk production in the next milking of 0.640 kg animal-1. A higher percentage of time spent on food intake and rumination (17.31 and 30.19%) in 30 minutes treatment, compared to control (15.50 and 27.37%), respectively. There was no significant effect of treatments in the composition of milk.UFRPE DTR, Campus Dois Irmãos. R. Dom Manuel de Medeiros, s/n, CEP. 52171-900, Recife, PEUFRPE/DZUNESP, Campus de Tupã, Av. Domingos da Costa Lopes, 780, CEP 17602-496, Tupã, SPUAG UFRPE, Av. Bom Pastor s/n, CEP 55296-901, Garanhuns, PEUNESP, Campus de Tupã, Av. Domingos da Costa Lopes, 780, CEP 17602-496, Tupã, S