title: Radiological and multi-element analysis of sediments from the Proserpina reservoir (Spain) dating from Roman times.
abstract: The Proserpina dam was built in Roman times to provide drinking water to Emerita Augusta (today's Mérida in SW Spain). During maintenance work, a sediment core was extracted, offering an excellent opportunity to analyze the historical environmental impacts of the dam and its reservoir over the 2000 years since Roman times. In order to establish an accurate chronology, (14)C ages were determined by accelerator mass spectrometry (AMS). Core samples were assayed for their content in uranium and thorium series isotopes, (40)K, and the anthropogenic radionuclides (137)Cs, (90)Sr, and (239+240)Pu. Potassium-40 presented the highest activity level and was not constant with depth. The uranium and thorium series were generally in equilibrium, suggesting there had been no additional input of natural radionuclides. The presence of (137)Cs was only found in relation with the global fallout in the early 1960s. Multi-element assays were performed using the PIXE and PIGE techniques. Some variations in the multi-element concentrations were observed with depth, but the sediment core could be considered as clean, and no presumptive anthropogenic pollutants were found. Nevertheless, an unusually high Zn content was detected at depths corresponding to pre-Roman times, due to geological anomalies in the area.
authors.affiliation: LARUEX, Department of Applied Physics, Faculty of Veterinary, University of Extremadura, Avda. Universidad s/n, Cáceres, Spain. ymiralle@unex.es
authors.forename: A
authors.initials: A
authors.lastname: Baeza
authors.forename: J
authors.initials: J
authors.lastname: Guillén
authors.forename: M A
authors.initials: MA
authors.lastname: Ontalba Salamanca
authors.forename: A
authors.initials: A
authors.lastname: Rodríguez
authors.forename: F J
authors.initials: FJ
authors.lastname: Ager
mesh_terms: D002250:Carbon Radioisotopes / Q000032:analysis; D002588:Cesium Radioisotopes / Q000032:analysis; D004602:Elements; D004787:Environmental Pollution / Q000266:history; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D049690:History, Ancient; D011005:Plutonium / Q000032:analysis; D011197:Potassium Radioisotopes / Q000032:analysis; D011834:Radiation Monitoring; D011868:Radioisotopes / Q000032:analysis*; D055110:Radiometric Dating; D018644:Roman World; D013030:Spain; D013326:Strontium Radioisotopes / Q000032:analysis; D013910:Thorium / Q000032:analysis; D014501:Uranium / Q000032:analysis; D014881:Water Supply / Q000032:analysis*
chemical_list: D002250:Carbon Radioisotopes; D002588:Cesium Radioisotopes; D004602:Elements; D011197:Potassium Radioisotopes; D011868:Radioisotopes; D013326:Strontium Radioisotopes; D014501:Uranium; D011005:Plutonium; D013910:Thorium