### Surficial geologic map of Berrien County, Michigan, and the adjacent offshore area of Lake Michigan

By: Byron D. Stone**Kevin A. Kincare**Dennis W. O'LearyWayne L. NewellEmily M. TaylorVan S. WilliamsScott C. LundstromJared E. AbrahamMichael H. Powers**

                            https://doi.org/10.3133/sim3383

#### Links

-                                                                                                                             Document:                                                                                                                                                                                                                                                  **Report (Pamphlet)**                                                                                                     (2.49 MB pdf)                                                                                                                                     
- Sheets:                               - **Map Sheet 1**                            (35.9 MB pdf)                        
  - **Map Sheet 2**                            (43.1 MB pdf) 
- Read Me:  **Read Me**                            (2.42 KB txt)                        
- Spatial Data:                               - **Geodatabase**                            (9.69 MB zip)                          - Contains SIM 3383.gdb (an ESRI ArcGIS v. 10.5 file geodatabase), and metadata and other files
  - **Geodatabase**                            (12.4 MB zip)                          - Complete, automatic translation of SIM 3383.gdb into shapefiles and other files; contains metadata
  - **Geodatabase**                            (12.4 MB zip)                          - Automatic translation of most of the contents of SIM 3383.gdb into simple flat shapefiles; contains metadata 
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#### Abstract

First posted December 13, 2017

**For additional information, contact:**
Eastern Geology and Paleoclimate Science Center U.S. Geological Survey 926A National Center 12201 Sunrise Valley Drive Reston, VA 20192

The surficial geologic map of Berrien County, southwestern Michigan (sheet 1), shows the distribution of glacial and postglacial deposits at the land surface and in the adjacent offshore area of Lake Michigan. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics, stratigraphic relationships, and age. Drill-hole information correlated in cross sections provides details of typical stratigraphic sequences that compose one or more penetrated geologic map units. A new bedrock geologic map (on sheet 2) includes contours of the altitude of the eroded top of bedrock and shows the distribution of middle Paleozoic shale and carbonate units in the subcrop. A sediment thickness map (also on sheet 2) portrays the extent of as much as 150 meters of surficial materials that overlie the bedrock surface.

The major physical features of the county are related principally to deposits of the last Laurentide ice sheet that advanced and then retreated back through the region from about 19,000 to 14,000 radiocarbon years before present. Glacial and postglacial deposits underlie the entire county; shale bedrock crops out only in the adjacent offshore area on the bottom of Lake Michigan. All glacial deposits and glacial meltwater deposits in Berrien County are related to the late Wisconsinan glacial advances of the Lake Michigan ice lobe and its three regional recessional moraines, which cross the county as three north-northeast-trending belts.

From east to west (oldest to youngest), the three moraine belts are known as the Kalamazoo, Valparaiso, and Lake Border morainic systems. The *till-ridge morainic systems* (Lake Border and local Valparaiso morainic systems) consist of multiple, elongate moraine ridges separated by till plains and lake-bottom plains. Tills in ground and end moraines in Berrien County are distinguished as informal units, and are correlated with three proposed regional till units in southwestern Michigan, characterized as clayey till, loamy till, or sandy loamy till that are based in part on correlation of silty tills and clay mineralogy. The *stratified morainic systems* (local Valparaiso and Kalamazoo morainic systems) are composed of multiple ice-marginal glacial-lake deltas and glaciolacustrine fans that form a contiguous array of deposits, welded together at their onlapping contacts, further related by the accordant altitudes of their delta topset plains. Their bounding ice-contact slopes repeatedly are aligned parallel to the regional trend of the receding ice margin. Ice-marginal (ice-contact) deltas were deposited in glacial lakes that expanded northward as the ice sheet retreated. Glaciofluvial topset beds, which overlie deltaic foreset and bottomset facies, fine away from the ice margin. Stratified deposits associated with the Valparaiso moraine were deposited in glacial Lakes Madron and Dowagiac. Subsequent deposits of glacial Lake Baroda preceded basin-wide deposits associated with various levels of Lake Michigan.

Sheet 2 includes a series of 10 map figures that show cut-away three-dimensional time slices of the stratigraphic succession, from basal tills on bedrock, to ice-marginal deltas in the three large proglacial lakes, to stacked till/lake-bottom deposits related to the Lake Border ice margin readvances, to young deposits of glacial Lake Chicago and younger phases of other glacial lakes and the Chippewa lake lowstand.

The pamphlet contains a discussion of the stratigraphic framework, descriptions of each depositional unit, and graphic logs of U.S. Geological Survey stratigraphic drill holes. The pamphlet also relates the geologic history of Berrien County, beginning with bedrock Paleozoic marine deposits, continuing through erosional effects of multiple glaciations and the detailed steps of late Wisconsinan ice-margin recession as recorded in the moraines, and the rise and fall of postglacial lake levels in the Lake Michigan basin.

#### Suggested Citation

Stone, B.D., Kincare, K.A., O'Leary, D.W., Newell, W.L., Taylor, E.M., Williams, V.S., Lundstrom, S.C., Abraham, J.E., and Powers, M.H., 2017, Surficial geologic map of Berrien County, Michigan, and the adjacent offshore area of Lake Michigan: U.S. Geological Survey Scientific Investigations Map 3383, 2 sheets, scale 1:50,000, and 49-p. pamphlet, https://doi.org/10.3133/sim3383.

ISSN: 2329-132X (online)

ISSN: 2329-1311 (print)

#### Study Area

#### Table of Contents

- Introduction
- Previous Geologic Studies and Maps of the Berrien County Region 
- Bedrock Surface Topography 
- Thickness of Glacial and Postglacial Deposits
- Lithostratigraphy of Berrien County
- Glacial Stratigraphy of Berrien County 
- Deposits of Postglacial Lakes and Streams in Berrien County 
- Late Quaternary Geologic History of Berrien County
- References Cited
- Description of Surface and Subsurface Map Units
- Description of Bedrock Map Units
- Appendix 1. Description of Stratigraphic Drill-Hole Logs

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