thumbnail

Hydrogeology and hydrochemistry of dunes and wetlands along the southern shore of Lake Michigan, Indiana

Open-File Report 92-139

By:
, , , and

Links

Abstract

The dunes and the wetlands along the southern shore of Lake Michigan are underlain by a complex aquifer system composed of unconsolidated glacial, lacustrine, and eolian deposits. Surficial dune, beach, and glacial lacustrine sands compose an extensive surficial aquifer. The underlying drift contains three major confined sand aquifers. Potentiometric and hydrochemical data are consistent with a conceptual model in which regional and intermediate flow systems, recharged in end moraines south of the dune-beach complexes, discharge into Lake Michigan and the Great Marsh by upward leakage through unconsolidated sediments. Local flow systems in the surficial aquifer, recharged in the major dune-beach complexes, discharge into streams, ditches, and ponded areas in the adjacent interdunal wetlands. Shallow ground water discharges directly into Lake Michigan only north of a water-table divide that underlies the dune-beach complex along the shoreline. The position of ground-water seepage faces is affected by transient water-table mounds observed in the dune-beach complexes at the margins of wetlands. Substantial recharge to the dune complexes probably occurs near these dune-wetland margins. In the dune-beach complexes and intradunal wetlands, the shallow ground and wetland waters are dilute calcium bicarbonate and calcium bicarbonate sulfate types. More mineralized bicarbonate water types having variable proportions of calcium, magnesium, and sodium are found in interior parts of the Great Marsh because this area is probably a discharge zone for the regional and intermediate flow systems.

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Hydrogeology and hydrochemistry of dunes and wetlands along the southern shore of Lake Michigan, Indiana
Series title:
Open-File Report
Series number:
92-139
Edition:
-
Year Published:
1994
Language:
ENGLISH
Publisher:
U.S. Geological Survey ; USGS Earth Science Information Center, Open-File Reports Section [distributor],
Description:
vi, 85 p. :ill., maps ;28 cm.