January 19, 2018

Carol Cheyne Article on the Utility of Lead Isotopes Published in Chemical Geology Journal

Carol Cheyne (Ontario) was the lead author of an article entitled "Lead isotopes as particulate contaminant tracers and chronostratigraphic markers in lake sediments in northeastern North America" published in the journal Chemical Geology in Volume 477, pages 47-57 on January 2018.

Carol's co-authors are Dr. Alyson Thibodeau (Dickinson College), Dr. Greg Slater (McMaster University), and Dr. Bridget Bergquist (University of Toronto).

The paper is based on Carol's M.A.Sc. thesis and it demonstrates the utility of lead isotopes in two applications:

  1. as a forensic tool to delineate atmospheric sources of lead and other trace metals in environmental archives; and
  2. as a chronostratigraphic tool to constrain the deposition dates of sediments.

The abstract is provided below and the full article can be found in the attached link.

Carol is an Environmental Scientist with a chemistry specialization. Her work is focused on providing clients with solutions to their contaminated soil, sediment, and groundwater problems. Carol recently completed her Masters of Applied Science degree at the University of Toronto where she conducted research in the Department of Earth Sciences. She is experienced in conducting field and laboratory studies pertaining to the assessment and remediation of contaminated sites. Carol is currently involved in numerous projects for the identification and remediation of hazardous contaminated sites.

Chemical Geology is an international journal that publishes original research papers on isotopic and elemental geochemistry, geochronology and cosmochemistry. The Journal focuses on chemical processes in igneous, metamorphic, and sedimentary petrology, low- and high-temperature aqueous solutions, biogeochemistry, the environment and cosmochemistry. Papers that are field, experimentally, or computationally based are appropriate if they are of broad international interest. The Journal generally does not publish papers that are primarily of regional or local interest, or which are primarily focused on remediation and applied geochemistry.

Abstract

The utility of lead (Pb) isotopes as tracers of particulate contamination and as chronostratigraphic markers was assessed in five lake sediment cores from the Great Lakes and southern Ontario region. The marker for smelting of highly radiogenic ores in the Upper Mississippi Valley in the mid-19th century was seen in the Pb isotopes in four lakes expanding the geographic range of this established marker into southern and central Ontario. This marker is useful for age-dating sediments deposited in the 1800s in archives where it is present. The estimated dates for this ~ 1850 marker using other dating methods span a range of 57 years, emphasizing the importance of the marker as a tie-point for extrapolated dates in the 19th century. Lead isotopes identified leaded gasoline as an important source only in one lake in the second half of the 20th century; its signal was not identified in all other lakes because the lakes were more affected by local and regional inputs. Lead isotopes combined with trace metal fluxes identified a potential marker for coal combustion or urban sources in the second half of the 20th century in southern Ontario, where these sources were significant enough to outweigh leaded gasoline input. The effects of Canadian mining and smelting activities were seen in the trace metal flux profiles of central Ontario lakes; however, these activities were not visible in the Pb isotopes, likely due to mixing of several sources with similar Pb isotopic signatures. This study demonstrates the usefulness of combining lead isotopes and trace metal flux profiles for identifying markers of historical and modern particulate contamination sources, especially in regions where several pollution sources exist.

More Information

Learn more about the article: Chemical Geology.
For consultation regarding lead isotope applications, contact Carol Cheyne at This email address is being protected from spambots. You need JavaScript enabled to view it..
Learn more about Carol: https://www.linkedin.com/in/carol-cheyne-5688a270/

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