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Michigan Glacial History

Michigan Glacial History. Extent of ice during Pleistocene glaciations. How thick was the ice that covered Michigan ?. Nobody can say for sure how thick the ice was that covered Michigan during the last glaciation. One could easily assume there was 2 kilometers (~1.25 miles).

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Michigan Glacial History

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  1. Michigan Glacial History

  2. Extent of ice during Pleistocene glaciations

  3. Howthick was theice that covered Michigan?

  4. Nobody can say for sure how thick the ice was that covered Michigan during the last glaciation. One could easily assume there was 2 kilometers (~1.25 miles).

  5. Anotherway to look at 2 kilometers of ice is - how many people would have to stand on each others shoulders to see over the top of the glacier.

  6. 97 97

  7. Is theweight of the glacierthat covered Michigan measured in hundreds, thousands, millions, trillions, quadrillions or quintillions of kilograms (or pounds) ?

  8. What did theweight of the glaciersdo to the land it covered?

  9. Howmanyice rinkswould the glacier fill?

  10. How manysnow conescould you make from the glacier?(for each and every person on earth)

  11. How much area did the glaciers cover?

  12. According to the National Snow and Ice Data Center (NSIDC), if all glaciers melted today the seas would rise about 70 meters (about 230 feet).

  13. During the last ice age, glaciers covered more land area than today, sea level was about 400 feet lower than it is today. At that time, glaciers covered almost one third of the land.

  14. During the last warm spell, ~125,000 years ago, the seas were about 6 meters (~18 feet) higherthan they are today.

  15. Aboutthree million years ago the seas could have been up to 55 meters (~165 feet) higher.

  16. How did the glacier retreat?

  17. Glacial deposits are much younger than the bedrockon which they are resting.

  18. How thick is the glacial material in your area of the state?

  19. How much ‘stuff’(sands, gravels & clays) was carried by the glaciers?

  20. Howmuchice? Howmuchice? =

  21. Howwouldyoufindout?

  22. What is the drift thickness in the state, in your area?

  23. How much material was in the glacier?

  24. When? Were there glaciers?

  25. Multiple glacial events are recorded in the geologic record.

  26. Pleistocene 3 millions of years ago Geologic age • Permian 250-220 • Ordovician 450 • Precambrian 900-650 2,300

  27. Which glacial period has the most complete geologic record?

  28. The most recent glaciation - The one that occurred during the Pleistocene

  29. Whystudyglaciers?

  30. Gravel Gravel Sand Clay Clay Sand

  31. Uses Amount Value

  32. Construction concrete and mortar road and roadbed construction asphalt construction fill and landscaping concrete blocks bricks & pipes shingles treating icy roads railroad ballast water filtration glass abrasive sand foundry sand (molded metal parts) Uses

  33. Amount • 76,900,000 metrictons Value $ 293,000,000 annually

  34. Lets review the geology of Michigan

  35. Everyone knows what the map of Michigan looks like

  36. Surface Geology Shows the complex groupsof sediments that were deposited by the glaciers. Generalized QuaternaryGeology of Michigan

  37. Bedrock Geology What you would find under all of the glacial material at the surface Generalized Bedrock Geology of Michigan

  38. Western Northern Peninsula Igneous and metamorphicrocks Oldest rocksmetallic ores

  39. Eastern Northern Peninsula Southern Peninsula Younger rocks Non-metallic minerals

  40. Glaciallandforms in Michigan

  41. The MOST recognized feature of Michigan is the GREAT LAKES

  42. All of Michigan, including the lakes, beaches, streams and abundant fresh water, are a result of glaciation All of Michigan, including the lakes, beaches, streams and abundant fresh water, are a result of glaciation

  43. {CLICK} When you click on the mouse, a block diagram of a glacialfeature found in Michigan will appear. {CLICK} When you click on the mouse a secondtime the name of that feature will appear in the lower right corner of the slide. This was done to help you become familiar with the terms and what they mean

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