An oral presentation given at the Michigan Academy of Science Meeting in 2007.

1. Welcome
to the Geological Sciences section of
the Michigan Academy of Sciences,
Arts, and Letters
2007 Meeting at Ferris State University

2. The glacial section at Grand
Valley State University: A
Lake Michigan lobe advance
into a glacial lake
Patrick M. Colgan
Grand Valley State University
Allendale, Michigan

3. Ottawa County
Michigan 10 kilometers N
Counties
Lake
Plain GVSU
Grand
Rapids
Lake
Border
Lake Border Advance of the moraines
Lake Michigan Lobe
~14,500-15,500 14C yrs B.P.

4. Allendale
Allendale Delta
GVSU
Campus end
moraine
Glacial
Lake Chicago
Plain
1 km

5. 1
Lake Ontario
Hall
N
2
500 meters

6. Section 1: Silt-rich diamicton with oxidized vertical joints, striated clasts, high density.

7. Dm
Dms
Sr-Sx
Section 1: Contact between diamicton and sand. Shear zone between.

8. clast of
diamicton
ripples
In silty
sand
Section 1: Clast of reddish diamicton in silty sand.

9. Sx-Sr
Fl
Sx-Sr
Fl
Sp
Section 1: planar bedded fine sands, crossbedding, ripples, and fines.

10. Sx-Sr
Fl
Sp
Section 1: laminated fines

11. Section 1 – Ravine Apartments
GV-1-2 (diamicton - basal till)
texture
meters C Z S GD sediment sediment 100
90
samples clay silt sand gr
facies 80
70
D1
% coarser
Dm erosional 60
surface D2 50
40
0 30
clast of Dm 1 20
10
Sr 0
0.0010 0.0100 0.1000 1.0000 10.0000
2
S1 diameter (mm)
Sx 3
GV-2-1 (sandy silt - glaciolacustrine)
4
100
Fm-Fl 90
5 clay silt sand gr
1 Sr S2
80
70
% coarser
60
Sx 50
40
30
Fm-Fl 6 20
S3 7a 10
Sp-Sr 7b 0
0.0010 0.0100 0.1000 1.0000 10.0000
8
Fm-Fl diameter (mm)
Sr S4 9
2 Fm-Fl 10 GV-2-13 (clayey silt - glaciolacustrine )
Sp S5
100
Fm-Fl 11 gr 90
clay silt sand
Sr S6 80
12 70
% coarser
60
50
40
covered 30
20
10
3 Fl-Fm
13 0.0010 0.0100 0.1000 1.0000
0
10.0000
diameter (mm)

12. 1
Lake Ontario
Hall
N
2
500 meters

13. Section 2: Silt-rich diamicton with striated and wedge shaped clasts.

14. rippled and cross-bedded
fine sands
fines
rippled and cross-bedded
fine sands
fines
rippled and cross-bedded
fine sands
planar bedded fine sands
trough cross-bedded sands
Section 2

15. Section 2 – planer bedded sand with scour of rippled sand

16. Section 2 – trough cross bedded sands

17. 2 cm
Section 2 - Granite clasts and clay rip-up clasts in laminated and deformed clay

18. Section 2 - Thick clay bed in fine sand.

19. meters C Z S G D
Section 3 – South Ravine
0 Fm-Dm
Samples
covered
St-Sr (A)
1 7 SR2-10 (fine sand)
Fl-Fm 9
Sr (A)
St-Sr (A) 6
Fl-Fm 8 100
St-Sr (A) 90
5
2 4 clay silt sand gr 80
Sl 70
% coarser
3
60
Sl 2 50
3 St-Sr (A) 1 40
Dml-Fl 18
30
St-Sr (A) 20
Fl-Fm 10
4 Sr
St-Sr (A) 0
Sr 15 0.0010 0.0100 0.1000 1.0000 10.0000
Fl-Fm 14
12 diameter (mm)
5 St-Sr
Fl-Fm
11
SR2-16 (silty clay)
Sr
6 10
St
100.0
90.0
Sl
80.0
7 70.0
% coarser
60.0
clay silt sand gr 50.0
St-Sr (A) 40.0
8 30.0
20.0
St
inclusions of clasts 10.0
of fines in sand 0.0
9 Dmm
Fm-Fl
16 0.0010 0.0100 0.1000 1.0000 10.0000
17 diameter (mm)
Sr (A)
10 St

20. 141 (523) 208 (520)
147 (518) 1
190 (510)
193 (479)
194 (479)
Lake Ontario
Hall
2
N
1 km

21. North to South Cross Section across GVSU Campus
Lake
diamicton Ravine
Ontario
(basal till) Apartments
Hall
Section 2
South Ravine
elevation (ft)
fine silty sand (lacustrine)
clay, silt and fine sand (lacustrine)
diamicton (basal till)? Marshall Sandstone
~ 480-510 feet
S distance (meters) N
vertical exaggeration ~16:1

22. Interpretations
• Upper diamicton is basal till deposited during
Lake Border advance.
• Lower sequence is interpreted as numerous
underflows (turbidites) of fine silty sand overlain
by thin rainout deposits of clay and silt.
• Till was deposited directly on lake sediments
and inclusions of till suggest that the advance
occurred as sediment was deposited into a
proglacial lake.
• Minor debris flows and rainout layers are
present.

23. Morainal bank sedimentation model
rain out of fine
silt and clay
underflows
of sand
(Sx-Sp-Sr)
deposition
debris
of basal till (Dm) clay and silt
flows (Dml)
(Fm-Fl)
Adapted from Benn and Evans (1998) after Powell and Domack (1995)

24. Future Work
• Collect vibracores in areas of poor
exposure to see how extensive the
lacustrine sediments are.
• Compare diamicton clasts in upper sand to
basal till with grain size and clay
mineralogy.
• Collect vibracores to see what is below the
measured sections.

25. Acknowledgements
• Thanks to the GVSU geomorphology
students who have worked on the ravine
sediments in projects with me and other
faculty at GVSU.