Welcome

to the Geological Sciences section of

the Michigan Academy of Sciences,

Arts, and Letters

2007 Meeting at Ferris State University

The glacial section at Grand

Valley State University: A

Lake Michigan lobe advance

into a glacial lakePatrick M. Colgan

Grand Valley State University

Allendale, Michigan

Michigan

Counties

Ottawa County

10 kilometers N

GVSU

Grand

Rapids

Lake

Plain

Lake

Border

morainesLake Border Advance of the

Lake Michigan Lobe

~14,500-15,500 14C yrs B.P.

1 km

Allendale

Delta

end

moraineGlacial

Lake Chicago

Plain

Allendale

GVSU

Campus

500 meters

N

1

Lake Ontario

Hall

2

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

Dm

Sr-Sx

Dms

Section 1: Contact between diamicton and sand. Shear zone between.

clast of

diamicton

ripples

In silty

sand

Section 1: Clast of reddish diamicton in silty sand.

Sx-Sr

Sp

Fl

Sx-Sr

Fl

Section 1: planar bedded fine sands, crossbedding, ripples, and fines.

Sp

Fl

Sx-Sr

Section 1: laminated fines

Section 1 – Ravine Apartments

SC Z

0

1

2

3

meters G

erosional

surface

covered

Fl-Fm

Sr

Sx

Fm-Fl

Sx

Fm-Fl

Dm

Sp-Sr

1

2

3

4

5

67a7b8

9

10

11

12

13

sediment

samplessediment

facies

texture

D1

D2

GV-1-2 (diamicton - basal till)

0

10

20

30

40

50

60

70

80

90

100

0.0010 0.0100 0.1000 1.0000 10.0000

diameter (mm)

% c

oars

er

sandsilt grclay

GV-2-1 (sandy silt - glaciolacustrine)

0

10

20

30

40

50

60

70

80

90

100

0.0010 0.0100 0.1000 1.0000 10.0000

diameter (mm)

% c

oars

er

sandsilt grclay

GV-2-13 (clayey silt - glaciolacustrine )

0

10

20

30

40

50

60

70

80

90

100

0.0010 0.0100 0.1000 1.0000 10.0000

diameter (mm)

% c

oars

er

sandsilt grclay

D

Sr

Sr

Sr

Fm-Fl

Fm-Fl

Fm-Fl

S1

S2

S3

S4

S6

S5

clast of Dm

Sp

500 meters

N

1

Lake Ontario

Hall

2

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

fines

fines

rippled and cross-bedded

fine sands

rippled and cross-bedded

fine sands

rippled and cross-bedded

fine sands

planar bedded fine sands

trough cross-bedded sands

Section 2

Section 2 – planer bedded sand with scour of rippled sand

Section 2 – trough cross bedded sands

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

2 cm

Section 2 - Thick clay bed in fine sand.

1

2

3

5

6

7

8

9

10

4

covered

Fm-Dm

inclusions of clasts of fines in sand

Fl-Fm

Fl-Fm

Fl-Fm

Dml-Fl

DmmFm-Fl

Fl-Fm

Fl-Fm

St-Sr (A)

St-Sr (A)

St-Sr

St

Sr (A)

St-Sr (A)

St-Sr (A)

St-Sr (A)

St

St

Sr

Sr

Sr

Sr (A)

St-Sr (A)

Sl

Sl

Sl

Samples

7

6

1

18

15

14

12

11

10

16

17

2

3

4

5

9

8

meters

St-Sr (A)

C Z S G D

0

SR2-10 (fine sand)

0

10

20

30

40

50

60

70

80

90

100

0.0010 0.0100 0.1000 1.0000 10.0000

diameter (mm)

% c

oars

er

sandsiltclay gr

SR2-16 (silty clay)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

0.0010 0.0100 0.1000 1.0000 10.0000

diameter (mm)

% c

oars

er

grsandsiltclay

Section 3 – South Ravine

1 km

1

Lake Ontario

Hall

2

N

193 (479)

194 (479)

141 (523)

147 (518)

190 (510)

208 (520)

fine silty sand (lacustrine)

diamicton

(basal till)

Marshall Sandstone

~ 480-510 feet

clay, silt and fine sand (lacustrine)

Section 2

South Ravine

Ravine

Apartments

ele

vati

on

(ft

)

distance (meters)S N

Lake

Ontario

Hall

vertical exaggeration ~16:1

North to South Cross Section across GVSU Campus

diamicton (basal till)?

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.

Adapted from Benn and Evans (1998) after Powell and Domack (1995)

rain out of fine

silt and clay

underflows

of sand

(Sx-Sp-Sr)

deposition

of basal till (Dm)debris

flows (Dml)clay and silt

(Fm-Fl)

Morainal bank sedimentation model

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.

Acknowledgements

• Thanks to the GVSU geomorphology

students who have worked on the ravine

sediments in projects with me and other

faculty at GVSU.