|
|||||
|
|
Refining the pre-industrial atmospheric Pb isotope evolution curve in Europe using an 8000 year old peat core from NW Spain |
|
| Authors: | ME Kylander DJ Weiss A Martínez Cortízas R Garcia-Sanchez |
| Institution: | a Department of Earth Science and Engineering, Imperial College London, SW7 2AZ, UK b Department of Mineralogy, The Natural History Museum, London SW7 5BD, UK c Departamento de Edafología y Química Agrícola, Faculdad de Biología, Universidad de Santiago de Compostela, Campus Sur E-15706, Santiago de Compostela, Spain |
| Abstract: | Pb pollution has existed for several millennia and remains relevant today. By using peat cores as environmental archives it is possible to reconstruct this long history on a regional scale. This is a significant contribution to the findings from ice core records, the only other archive recording purely atmospheric additions. Without information that allows linking and comparison between sites regionally, within Europe and elsewhere, our ability to make coherent global models of the natural Pb cycle, and anthropogenic forcing of this cycle, is limited. In this respect, the characteristics of the Pb pre-pollution aerosol (PPA) are important to define globally. We characterize for the first time a PPA in Southern Europe with Pb] = 0.78 ± 0.86 μg g− 1, net Pb accumulation rates of 0.032 ± 0.030 mg m− 2 y− 1 and a 206Pb / 207Pb signature of 1.25470 ± 0.02575. This PPA Pb isotope signature is more radiogenic than that found thus far in Western and Northern Europe. Spain is a historically important mining site. Using three-isotope plots and a pool of potential Pb isotope signatures, a detailed source appointment of both natural and anthropogenic Pb sources was made. We found evidence of Saharan aridification and its termination ∼4400 BP and/or agricultural signals and strong local control (from rock and soil) of the Pb PPA. Human impact is first recorded at 3210 BP but does not exceed 50% of deposited Pb until 3005 BP. Mines in SE Spain dominate early Pb pollution history at this site. During the rise of Roman rule, contributions come from mines in N, NW and SW Spain with no strong indication of other European mining activities. In Medieval and Industrial times local contributions to the peat bog are reduced. |
| Keywords: | Pb isotopes pollution ombrotrophic peat Saharan aridification Spain climate atmospheric deposition |
| 本文献已被 ScienceDirect 等数据库收录！ | |