The Finger Lakes Institute presents:

1. The Finger Lakes Institutepresents: Mountains, oceans, and rivers of ice: The Geology of the Finger Lakes Region. Eric Primrose Education Outreach Coordinator

2. The bedrock of the Finger Lakes Nearly flat lying (1-3 degree dip to the south) Bedrock outcrops in narrow, east-west bands across the state. Northern outcrops older rock, southern outcrops younger rock

3. Geologic time in the Finger Lakes Exposed bedrock: Mid Paleozoic sedimentary rocks Silurian-Devonian in age No geologic record preserved from late Paleozoic to late Cenozoic Pleistocene age glacial sediments, landforms and landscapes dominate current topography

4. Silurian Global map: 438-415 MYA

5. The Silurian Oceans of New York Much of New York was a shallow ocean during Silurian times Represented a continental shelf on the western border of North America Shallow, tropical ocean- North America roughly 15 degrees south of Equator

6. Plate Tectonics In New York? Early-mid Ordovician (500-46- mya) Taconic Orogeny creates massive mountains on eastern margin of proto-North America Sediments erode to shallow ocean in the west from Taconic mountains in the east Erosion produces late Ordovician to early Silurian sedimentary rocks in continental shelf basin, including Clinton group

7. Silurian age sediments Fine grained clastic and carbonate rocks indicate a shallow ocean environment Sediments deposited from East- Taconic Orogeny Shallow ocean evaporated repeatedly late in the Silurian due to sea level changes, left thick deposits of evaporites during late Silurian (Syracuse formation)

8. Life in the Silurian oceans Include animals such as: Trilobites Brachiopods Corals (Tabulate and Rugose) Cephalopods Crinoids Eurypterids (Sea Scorpions)

9. Devonian Period: 415-360 MYA

10. The Devonian oceans of New York A shallow inland ocean New York is still in tropical regions Shallow tropical oceans create an environment where carbonates are formed Coral reef communities dominate the fauna of Early Devonian New York

11. Acadian Orogeny Continued subduction on eastern margin of proto- North America Avalon Island arc collides with continent in Middle Devonian, creating Acadian Orogeny Central and western NY are a shallow inland ocean Erosion of Acadian Mountains create Catskill Clastic wedge.

12. Bedrock from Late Devonian times Acadian Mountains erode in the east, producing a wedge of sediments spreading out to the West Catskill clastic wedge produces the clastic sediments that form the middle and late Devonian bedrock of Central New York Deep water environments accumulate thick section of clay muds, producing massive thicknesses of shale bedrock common in Finger Lakes area Later Devonian sediments grow larger in grain size as ocean basin fills with sediment from Acadian mountains to the east

13. Devonian Life Reef communities are prevalent early in Devonian Animal groups common in the Silurian still predominate Corals (Rugose and Tabulate) Brachiopods Crinoids Trilobites Cephalopods Fish become a important player in ecosystems

14. The Pleistocene Glaciation: 2 MYA to 14,000 years ago A period of cooler global temperatures Continental glaciers formed, and advanced across the Finger Lakes region Scoured soil and bedrock from the land, altering the landscape

15. Pleistocene global map

16. The Finger Lakes before the glaciers Before the glaciers came, the Finger Lakes were a series of river valleys, draining the highlands of the north to the Chesapeake bay area to the south.

17. Glaciers-Continents of ice Increased snowfall and cooler summers create continental ice sheet in eastern Canada As ice sheet thickens, it flows outward due to its immense weight. The ice sheet, almost 2 km thick, bulldozes everything in its path. Finger Lakes soil and sections of bedrock is removed.

18. Why did the Finger Lakes form where they did? Shale! The Finger Lakes occupy old river valleys Glaciers dug deep in to river valleys that cut through a thick bed of shale (90 meters) that outcrops in the Finger Lakes region

19. U-shaped valleys Glaciers carved the v shaped valleys of the rivers in the region in to the unshaped valleys that the Finger Lakes now occupy

20. Glacial features The glacier left many other features in the land as they retreated from the Finger Lakes region 14,00 years ago

21. The bedrock, where exposed, has scratches and gouges in it, oriented roughly North/SouthThese gouges are called striations

22. Drumlins: long, skinny hills oriented north/south

23. The sediments in drumlins are a mixed up jumble of rocks and dirt called glacial till

24. A boulder or rock that seems out of place is called an erratic

25. Long, low ridges, that to run East/West are called moraines. Composed of till

26. Eskers

27. Kames Small, cone shaped hills Created by cascades of water off the edges or through a hole in the glacier

28. There are spectacular waterfalls in gorges along the shores of the Finger Lakes

29. Hanging valleys Smaller valley glaciers in tributary streams Eroded smaller valleys Valleys were far above main valley floors, creating water falls.

30. The Finger Lakes are Gorges! Taughannock Falls, Watkins Glen, and Buttermilk Falls all started out as hanging valleys Erosion over the past 14,00 years has worked these hanging valleys back away from the main valley, creating gorges

31. Glacial Critters Pleistocene animals include Woolly Mammoth Wooly Rhino Dire wolves Fossil remains are found in bogs, ponds, and glacial till

32. Human Impact Invasive species Industry Mining of geologic riches Increased salinity of Seneca and Cayuga lakes? Draining of marshes and swamps Creation of man-made waterways Ground water usage