Sediment radioisotope dating across a stratigraphic discontinuity in a mining-impacted lake
Document Type
Article
Publication Date
2007
Department
Department of Civil, Environmental, and Geospatial Engineering
Abstract
Application of radioisotope sediment dating models to lakes subjected to large anthropogenic sediment inputs can be problematic. As a result of copper mining activities, Torch Lake received large volumes of sediment, the characteristics of which were dramatically different from those of the native sediment. Commonly used dating models (CIC-CSR, CRS) were applied to Torch Lake, but assumptions of these methods are violated, rendering sediment geochronologies inaccurate. A modification was made to the CRS model, utilizing a distinct horizon separating mining from post-mining sediment to differentiate between two focusing regimes. 210Pb inventories in post-mining sediment were adjusted to correspond to those in mining-era sediment, and a sediment geochronology was established and verified using independent markers in 137Cs accumulation profiles and core X-rays.
Publication Title
Journal of Environmental Radioactivity
Recommended Citation
McDonald, C. P.,
&
Urban, N. R.
(2007).
Sediment radioisotope dating across a stratigraphic discontinuity in a mining-impacted lake.
Journal of Environmental Radioactivity,
92(2), 80-95.
http://doi.org/10.1016/j.jenvrad.2006.09.009
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/6683