Date of Graduation

Spring 5-2012

Level of Access

Open Access

Degree Name

Bachelor of Science

Department or Program

Environmental Studies

Second Department or Program

Geology

Number of Pages

112

First Advisor

Dyk Eusden

Abstract

Contamination of groundwater due to the leaching of cations from bedrock can be a serious threat to public health. It is therefore important for geologists to identify potential hazards to bedrock groundwater systems. Small Point, a peninsula located in mid-coast Maine, is an important study location as there is no municipal water supply; residents must rely either on groundwater or a rainwater cistern for drinking water. The objectives of my study are to determine the: (1) relationship between groundwater and leached cations from bedrock, (2) mineral phases where cations are present and the likelihood of mobilization, and (3) implications on the public, namely where are the best and worst places to extract groundwater. For this analysis 10 different sample lithologies, determined from extensive mapping of the Small Point peninsula were studied. These lithologies include Fe-S and Al bearing schists, amphibolites, calc-silicates, and a graphitic phyllite. Using leaching experiments, where each unit was crushed and exposed to slightly acidified rainwater (pH 5.5), it was determined which of the cations found in each rock unit may actually become mobilized within the groundwater system. Inductively coupled plasma atomic emission spectroscopy (ICP-AES), was used to complete this analysis. Leaching indicates that the most mobile cations are found in schists, in particular the Singing Sands Silver Schist(Ossss), as well as in the Icebox Amphibole-Rich Calc-Silicate(Oiacs) sample. Lithologies that did not mobilize cations easily include the Graphitic Phyllite (Ogp) and the West Marsh Schist (Owms). Using leaching experimetns in conjunction with the bedrock geology map developed by Sive (2012), it can be determined preliminarily which areas are the best and least suited to bedrock wells.

Components of Thesis

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