Geology topics

T.D. Conlon

Publications and source records attributed to T.D. Conlon.

4 recordsLinked to original sources

USGS1998

Hydrogeology and simulation of ground-water flow in the Sandstone Aquifer, northeastern Wisconsin

Municipalities in the lower Fox River Valley in northeastern Wisconsin obtain their water supply from a series of permeable sandstones and carbonates of Cambrian to Ordovician age. Withdrawals from this "sandstone aquifer" have resulted in water levels declining at a rate of more than 2 feet per year. The U.S. Geological Survey, in cooperation with the major water utilities in the Fox Cities area, the East Central Wisconsin Regional Planning Commission and the Wisconsin Geological and Natural History Survey, collected hydrogeological data and constructed a quasithree- dimensional, transient ground-water-flow model for use as a tool in assessing the water resources of the sandstone aquifer. The rocks of the Sinnipee Group and Maquoketa Shale form the Maquoketa-Sinnipee confining unit that separates the sandstone aquifer from the overlying upper aquifer, which consists of unconsolidated deposits and permeable dolomite of Silurian age. The confining unit is present in the eastern part of the study area, but is absent in the western part, where the upper aquifer directly overlies the sandstone aquifer. The ground-water-flow model simulates water levels in the two aquifers and vertical flow across the confining unit. Streams and lakes are simulated in the upper aquifer as head-dependent boundaries where the confining unit is absent and as constant head boundaries where the confining unit is present. The sandstone aquifer has constant heads assigned to the southern boundary, which is far from the lower Fox River Valley and coincident with a ground-water divide. The model was calibrated to predevelopment, 1957, and 1990 water levels, and used to simulate steady-state predevelopment conditions and transient conditions from 1880 to 1990. The trend in simulated water levels over time was similar to trends in measured water levels. Simulated base flow to streams was within the calculated range of base flow at gaged streams. A groundwater divide that separates westerly ground-water flow to the Wolf River from easterly flow to the lower Fox River Valley and Lake Michigan was simulated.

Wisconsin↗

USGS1996

Hydrogeology of the sand and gravel aquifer in the vicinity of the Wild Rose State Fish Hatchery, north-central Waushara County, Wisconsin

The sand and gravel aquifer in the vicinity of the Wild Rose State Fish Hatchery is approximately 200 feet thick. The aquifer consists mostly of sand that was deposited as glacial till and outwash approximately 15,000 years ago. Hydraulic conductivity of the aquifer at the hatchery, calculated from slug tests, is approximately 18 feet per day. Ground water recharges west of the hatch ery, flows from northwest to southeast, and discharges to streams, lakes, springs, and flowing wells. Springs and flowing wells are common at the hatchery because of upward hydraulic gradients in the sand and gravel aquifer. Total flow from springs and wells at the hatchery is approximately 3 million gallons per day. The recharge area for the ground water discharging at the hatchery extends at least 5 miles to the west. Ground water may flow from or under the Pine River to wells and springs at the hatchery.

Wisconsin↗

USGS1995

Hydrogeology of southwestern Sheboygan County, Wisconsin, in the vicinity of the Kettle Moraine Springs fish hatchery

This report describes the hydrogeology of the dolomite aquifer of Silurian age and its relation to springs in a study area in southwestern Sheboygan County, Wisconsin. The study was conducted at the Kettle Moraine Springs fish hatchery in cooperation with the Wisconsin Department of Natural Resources. The dolomite aquifer is overlain by more than 60 feet of glacial deposits. Fine-grained glacial deposits confine the dolomite aquifer in the lowland at the hatchery. Thicker, coarse-grained glacial deposits overlie the dolomite aquifer on the hills surrounding the hatchery. The coarse-grained deposits are in good hydraulic connection with the aquifer. The transmissivity and storage coefficient of the dolomite aquifer are 1,220 feet squared per day and 0.0007, respectively. Pumping from the aquifer results in drawdown in wells open to the aquifer and the effects of this pumping will decrease the greater the distance between wells. The amount of drawdown caused by pumping was estimated by means of distance-drawdown curves. Five springs and two wells open to the dolomite aquifer supply water to the hatchery. Groundwater withdrawals from fish hatchery wells affect the water level in an observation well near the springs and probably decrease the flow from the springs to the hatchery. Additional pumping from the aquifer probably will further decrease flow from the springs.

Wisconsin↗

USGS1993

Hydrogeology of glacial deposits in a preglacial bedrock valley, Waukesha County, Wisconsin

This report describes the areal extent, thickness, and hydraulic properties of glacial deposits in a preglacial bedrock valley south of the city of Waukesha in southeastern Wisconsin. In the 40- square-mile study area, the preglacial bedrock valley underlies an area across which the Fox River flows. A previous regional study of the area indicated that extensive glacial sand and gravel deposits may exist in the preglacial bedrock valley. New test-hole, well-construction, and seismic data collected from 1986 through 1991 showed that the preglacial bedrock valley immediately south of the city of Waukesha is narrower and shallower than previously thought. However, these data indicate that thicknesses of saturated glacial deposits in excess of 250 feet exist in a 1- to 2-mile-wide part of the valley in the southern part of the study area. Test-hole logs indicate that clean sand and gravel deposits are present in a shallow part of the preglacial bedrock valley. Fifty to sixty feet of silty and clayey sand and gravel deposits appear to underlie varying thicknesses of relatively impermeable clay till in the center of the study area. Ground water flows from upland areas on the eastern and western sides of the Fox River and discharges to the Fox River and wetlands adjacent to the river. Results of a 6.5-hour aquifer test indicate that the silty sand and gravel deposits have an average transmissivity of about 140 feet squared per day and an average storage coefficient of about 1.2x10"3 at one location. The horizontal hydraulic conductivity of these deposits averages about 4 feet per day. Analysis of drawdown indicates that these deposits are part of a leaky confined-aquifer system and that some water is derived from storage in an overlying clay layer. The transmissivity value determined from this aquifer test and a lack of clean sand and gravel encountered in other test holes indicate that glacial deposits at these sites may not yield enough water for a large municipal water supply. Sand and gravel deposits, capable of development as a municipal supply, may be present in the southern part of the study area. However, additional test holes are needed to determine whether adequate sand and gravel deposits underlie this area.

Wisconsin↗