HR: 0800h
AN: V41G-1544    [Abstracts]
TI: Seaching for a Silver Lining: Using Pb Isotopes to Constrain the Source of Argentiferous Galena at La Isabela
AU: * Thibodeau, A M
EM: amt@geo.arizona.edu
AF: Department of Geosciences, University of Arizona, 1040 E. 4th St., Tucson, AZ 85721 United States
AU: Killick, D J
V41G-1544 AF: Department of Anthropology, University of Arizona, 1009 E. South Campus Dr., Tucson, AZ 85721 United States
AU: Ruiz, J
V41G-1544 AF: Department of Geosciences, University of Arizona, 1040 E. 4th St., Tucson, AZ 85721 United States
AU: Chesley, J T
V41G-1544 AF: Department of Geosciences, University of Arizona, 1040 E. 4th St., Tucson, AZ 85721 United States
AU: Baker, M
V41G-1544 AF: Department of Geosciences, University of Arizona, 1040 E. 4th St., Tucson, AZ 85721 United States
AB: This study investigates the smelting and refining of argentiferous galena at La Isabela, Dominican Republic (1493-1498), the town founded by Columbus on his second voyage to the Americas. Archaeologists recovered approximately 100 kilograms of galena and 200 kilograms of metallurgical slag near the remains of a crude furnace unearthed at the site (Deagan and Cruxent 2002). The purpose of this study was to determine if these remains are evidence that members of Columbus's fleet prospected for silver during his second expedition. Samples of ore and slag were examined as metallographic polished sections, and petrographic thin sections by optical and scanning electron microscopes. The composition of the ore and slag allows us to infer these ores were processed in a two-stage procedure to produce silver metal and a lead silicate slag. Electron microprobe analysis of galena indicates highly variable but low Ag content (50 ppm), which may account for the fact some of the ore was left unprocessed. Lead isotope analysis by multi-collector ICP-MS indicates that the galena likely came from a single source and was not mined within the Caribbean. Instead, the isotopic signature of these ores is consistent with an Old World source, possibly in the Linares-La Carolina Pb-Zn vein field of southwestern Spain.
DE: 1000 GEOCHEMISTRY
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005