Department or Program

Geology

Abstract

Global anthropogenic activity and resultant environmental emissions significantly alter atmospheric lead concentration. Records of atmospheric lead emissions are preserved throughout the world in lake sediments. Basin Pond, in Fayette, Maine, at 32 meters deep and .109 in surface area, is devoid of any nearby anthropogenic impacts, and therefore records the variance in atmospheric anthropogenic pollutants alone in its undisturbed varved sediment. A freeze core was collected from Basin Pond to analyze the historic atmospheric lead deposition throughout the entire core. Thin sections of the core were created in attempts to find an age model for the core and the lead concentration was analyzed throughout the core using ICP-OES analysis. The sediments in the thin sections were muddled, so an average of age models from Miller, (2015) was used to estimate the relative age of sedimentation throughout the core. Results indicated 3 major trends in atmospheric lead concentration throughout the core, with low initial background levels at ~5 mg Pb/kg sediment and peak levels at ~120 mg Pb/kg sediment. A rise and fall from 1590 to 1681 may indicate increased mining in Virginia at the time followed by the rise of tobacco plantations. A rise and fall from 1895 – 1987 may indicate the increased usage of leaded gasoline followed by the phasing out of lead as a gasoline additive in the 1970s. A rise from the 1990s to the present could indicate recent increased lead mining and fossil fuel emissions from China and a few other countries. This final rise in lead concentration goes against the observed results for lakes throughout the United States, and should be investigated further to confirm its validity.

Level of Access

Restricted: Embargoed [Open Access After Expiration]

First Advisor

Beverly Johnson

Date of Graduation

5-2020

Degree Name

Bachelor of Arts

Number of Pages

55

Embargoed

Available to all on Friday, August 20, 2021

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