McCarthy, Francine MG;
Patterson, Timothy;
Head, Martin J;
Riddick, Nicholas L;
Cumming, Brian F;
Hamilton, Paul B;
Pisaric, Michael FJ;
... McAndrews, John H; + view all
(2023)
The varved succession of Crawford Lake, Milton, Ontario, Canada as a candidate Global boundary Stratotype Section and Point for the Anthropocene series.
Anthropocene Review
10.1177/20530196221149281.
(In press).
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Abstract
An annually laminated succession in Crawford Lake, Ontario, Canada is proposed as the Global boundary Stratotype Section and Point (GSSP) for the Anthropocene as a series/epoch with a base dated at 1950 CE. Varve couplets of organic matter capped by calcite precipitated each summer in alkaline surface waters reflect environmental change at global to local scales. Spheroidal carbonaceous particles and nitrogen isotopes record an increase in fossil fuel combustion in the early 1950s, coinciding with fallout from nuclear and thermonuclear testing—239+240Pu and 14C:12C, the latter more than compensating for the effects of old carbon in this dolomitic basin. Rapid industrial expansion in the North American Great Lakes region led to enhanced leaching of terrigenous elements by acid precipitation during the Great Acceleration, and calcite precipitation was reduced, producing thin calcite laminae around the GSSP that is marked by a sharp decline in elm pollen (Dutch Elm disease). The lack of bioturbation in well-oxygenated bottom waters, supported by the absence of fossil pigments from obligately anaerobic purple sulfur bacteria, is attributed to elevated salinities and high alkalinity below the chemocline. This aerobic depositional environment, unusual in a meromictic lake, inhibits the mobilization of 239Pu, the proposed primary stratigraphic guide for the Anthropocene.
| Type: | Article |
|---|---|
| Title: | The varved succession of Crawford Lake, Milton, Ontario, Canada as a candidate Global boundary Stratotype Section and Point for the Anthropocene series |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1177/20530196221149281 |
| Publisher version: | https://doi.org/10.1177/20530196221149281 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | acid precipitation, combustion, Dutch Elm disease, Environmental Sciences, Environmental Sciences & Ecology, Environmental Studies, EUTROPHICATION, FLY-ASH PARTICLES, fossil plankton, Geology, Geosciences, Multidisciplinary, Great Acceleration, Life Sciences & Biomedicine, MEROMICTIC LAKE, mu XRF, Physical Sciences, radionuclides, RECORD, Science & Technology, SCPs, SEDIMENTS, SOUTHERN ONTARIO, stable isotopes, varves, WORKING |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL SLASH UCL > Provost and Vice Provost Offices > UCL SLASH > Faculty of S&HS UCL > Provost and Vice Provost Offices > UCL SLASH > Faculty of S&HS > Dept of Geography |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10167569 |
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