Date of Award


Document Type


Degree Name

Master of Arts (MA)



First Advisor

J.R. Reid


Wood Lake is a kettle lake within the McHenry end moraine (late Wisconsinan) in eastern Benson County, North Dakota. It is part of the Devils Lake interior basin, near the drainage divide between the Devils Lake basin and the Big Coulee - Sheyenne River drainage. The moraine deposits, part of the Coleharbor Group, are composed of complexly interfingering lenses of gravel, sand, silt, and clay within the till.

Water levels in piezometers around Wood Lake indicate groundwater flows from the southwest into the west side of the lake and out of the lake along the east shore, toward the northeast. High hydraulic conductivities, as determined from slug/bail tests, indicate the fine-textured glacial deposits around the lake are fractured,

Wood Lake is nearly equidistant between two glacio fluvial aquifers, the Tokio to the west, which follows the drainage of Big Coulee toward the Sheyenne River, and the Warwick to the east. The lake may serve as a recharge source for the Warwick aquifer.

Groundwater flowing toward the lake is of a calcium bicarbonate water type, whereas the lake itself has a magnesium bicarbonate water type, The calcium bicarbonate groundwater reflects the close proximity of the recharge area along the regional divide, and the higher rate of dissolution of calcite over dolomite. Cation exchange reactions, and mixing of groundwater and the lake water along the northern and eastern shores, are the maj6r hydrogeochemical processes responsible for the variety of water types found to the north and east of Wood Lake. The other types of water around Wood Lake include magnesium calcium bicarbonate, calcium-magnesium bicarbonate, and calcium-magnesium-sodium bicarbonate. In one isolated case, one water table piezometer produced a sodium sulfate water type, reflecting cation exchange of calcium for sodium from sodium-montmorillonitic clays, and sulfate derived from either the oxidation of iron sulfide minerals or local dissolution of gypsum, or both. A deeper piezometer associated with this particular site had a calcium bicarbonate water type, indicating the sodium sulfate water is restricted to an area at or near the top of the water table.

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