Archaeometallurgy in the Paraná Delta (Argentina): Composition, manufacture, and indigenous routes

The results of macroscopic, microscopic, and metallographic studies of archaeological metal objects from the Delta of the Paraná River (Argentina, South America) are presented. The aim of these studies was to determine the chemical composition and the manufacturing techniques of these allochthonous objects frequently placed in human burials. The results were discussed taking into account archaeological and ethnohistorical information in order to understand the significance of metals and the indigenous routes to the Paraná River. We concluded that the metal pendants and beads recovered in the Paraná Delta were manufactured from copper by casting in open moulds and hammering. Finished metal objects reached the Paraná River as a result of exchange circuits involving transport across pre-Hispanic routes from the production centres in the Andes. Metal objects from distant geographical areas were used to mark social ranks within the groups and were symbols of prestige displayed by local leaders.Facultad de Ciencias Naturales y MuseoConsejo Nacional de Investigaciones Científicas y Técnica

Chemical Etching and TEM Crystalline Quality Assessment of Single Crystalline ZnSe Ingots Grown by I2 Vapor Phase Transport

Crystalline defects were studied in single crystalline ZnSe grown by chemical transport using I2 as gaseous carrier. Transmission electronic microscopy determined an excellent structural order in the micrometric and nanometric range. Larger material areas were studied by chemical etching using different reagents to determine average dislocations density and average adjacent subgrains misorientation. Comparable micrographic results of different reagents are shown. Characterization values of ZnSe commercial substrate grown by High Pressure Bridgman (HPB) have been compared to those that correspond to our grown material wafers. Characterization proved that the semiconductor crystalline quality in our wafers is appropriate for optical devices