Glacial megasequences as a basis for ground-water sensitivity mapping at the head of Lake Michigan

Conference · Fri Apr 01 00:00:00 EST 1994 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:6859630

Bleuer, N K; Woodfield, M C ^[1]

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1. Indiana Geological Survey, Bloomington, IN (United States)

The Valparaiso and Calumet megasequences mapped at the head of Lake Michigan in northwestern Indiana are large-scale, three-dimensional, glacial-lacustrine, and lacustrine packages successively inset into basins left by the collapse of earlier ice masses. These map units are the basis for assessing groundwater sensitivity in Porter County, an area representative of the rural to heavily industrialized southern Lake Michigan rim. Facies within these megasequences record repeated southward and upward progression of more ice-proximal facies, representative of repeated southward and upward progression of more ice-proximal facies, representative of repeated ice advance out of the basin. The Valparaiso megasequence is a single lake-bottom to subaerial head-of-fan progression. The inset Calumet megasequence (Lake Border/Wheeler sequences; Lake Michigan sequence) is a multiple lake, subaqueous fan, to push-moraine progression followed by further inset of multiple lake bottom, delta, and beach progressions related to early phases of Lake Michigan. The variability within the megasequences make traditional surficial mapping or DRASTIC''-style ground-water sensitivity analysis difficult to justify. Instead, the nature of variability itself is of absolute importance. For this reason, an extensively illustrated atlas serves as a map explanation, type'' gamma-ray-log profiles illustrate variation in vertical sequence, and cross sections illustrate variation in overall geometry. Accompanying discussions outline elements of ground-water sensitivity related to various between and within-sequence geometries.

• OSTI ID: 6859630
• Report Number(s): CONF-9404217-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 26:5; Conference: 27. annual conference of the North-Central Section of the Geological Society of America (GSA), Kalamazoo, MI (United States), 28-29 Apr 1994; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
54 ENVIRONMENTAL SCIENCES
GEOLOGIC DEPOSITS
HYDROLOGY
STRATIGRAPHY
GROUND WATER
MAPPING
INDIANA
LAKE MICHIGAN
MORAINES
SITE CHARACTERIZATION
DEVELOPED COUNTRIES
GEOLOGY
GREAT LAKES
HYDROGEN COMPOUNDS
LAKES
NORTH AMERICA
OXYGEN COMPOUNDS
SURFACE WATERS
USA
WATER
580000* - Geosciences
540250 - Environment
Terrestrial- Site Resource & Use Studies- (1990-)