1. (with a focus on Honeoye Lake)
Glacial Geology of the
Finger Lakes
(with a focus on Honeoye Lake)

2. Honeoye Valley Association
Annual Meeting
Saturday, July 13, 2019
Dr. Bruce Gilman Department of Environmental Conservation and Horticulture Finger Lakes Community College 3325 Marvin Sands Drive Canandaigua, New York

3. Acknowledgements Dr. Richard Young, SUNY Geneseo
Dr. David Barclay, SUNY Cortland
Dr. Henry Mullins, Syracuse University
and
Herman Leroy Fairchild, University of Rochester

4. THE PLEISTOCENE, “GREAT ICE AGE”
A Very Different North America
20,000 years ago

5. Landscapes covered by slowly flowing ice

6. Global temperatures were 7º to 14º C colder than today

7. Ocean levels fell by over 100 meters (300 feet)!
A cycle that repeated itself several times during the Great Ice Age

8. starting ~2.5 million years ago
Pleistocene Ice Ages
starting ~2.5 million years ago
ending 10,000 years ago
Warmer & less ice
Colder & more ice
Glaciations
Interglaciations
Raymo, 1992

9. How extensive?
10% of our modern landscape is covered by glacial ice.
During the Great Ice Age,
32% of the global land surface was covered!

10. Today
Quaternary North America - Ron Blakey

11. 20,000 years ago Greenland IS Laurentide Ice Sheet
Quaternary North America - Ron Blakey

12. Honeoye Region at the peak of glaciation
Antarctica - Kevin McMahon

13. Ice Sheet Margin advancing across upstate NY
Lake
Uplands

14. Selective Linear Erosion
Glacial ice has a preference to move in pre-existing stream valleys aligned with basal flow direction – it’s the area of least resistance!
Any meanders in the original stream flow pattern are straightened out – glacial ice does not bend!

15. Selective Linear Erosion at work in the Finger Lakes

16. Finger Lakes Formation Story (pre-glaciation drainage patterns)
Ontario basin C I S R B H G A
A = Athens

17. Finger Lakes Formation Story (ice sheet advance)
Ontario basin C I S R B H G A
Proglacial lakes

18. Finger Lakes Formation Story
(ice sheet maximum)
Ontario basin C I S R B H G A

19. Finger Lakes Formation (Valley Heads Moraine deposition)
Ontario basin C I S R B H G A

20. Finger Lakes Formation (Drainage Divide Today)
Ontario basin C I S R B H G A

21. Water Erosion
V-shaped
rocky stream bed
Ice Erosion
U-shaped
glacial sediment fill

22. The Finger Lakes Region contains 28 broad U-shaped glacial troughs,
11 of these valleys are doubly dammed (north and south ends)
by moraine deposits and contain water!

23. Regional drainage at the time of Glacial Lake Honeoye

24. Glacial Lake Honeoye Landscape, 12,000 years ago
Alaska – Ice Park Campground
Glacial Lake Honeoye Landscape, 12,000 years ago

25. Giant Beaver

26. Ice Age Peccary

27. American Mastodon

28. Wooly Mammoth

31. Migrating herds of large herbivores
I couldn’t resist – great movie!

32. Saber-Tooth Cat

33. Dire Wolf and Peccary

34. Giant Short-faced Bear

35. With the Predators came the first Americans, Stone Age hunters

36. for attending today’s annual meeting
THANK YOU
for attending today’s annual meeting