Geology of Idaho

1. Geology of Idaho The Snake River Plain

2. Idaho can be divided into 6 natural geologic regions, each with its own unique characteristics

3. Clearwater Plateau Northern Rockies Snake River Plain Middle Rockies Owyhee- Bruneau Plateau Basin & Range Province

4. The Columbia Plateau spills over into other states from Washington, even into 3 regions of Idaho

5. Columbia Basalts show many layers from many sequential flows

6. These are the 3 regions of Idaho that share a volcanic origin by extension of the Columbia Plateau Clearwater Plateau Snake River Plain Owyhee-Bruneau Plateau

7. Gently rolling hills and valleys; a thinly-spread grassland with some desert-like vegetation

8. Some cinder cones, erroneously called “buttes”, are located in this dry grassland

9. Rivers and their tributaries have left their impact on the plain

10. The Snake River is the main one, arising from Jackson Lake in Jackson Hole, WY, on the eastern slope of the Grand Teton range

11. It flows westward across the southern edge of the SRP. Over thousands of years it has eroded huge canyons in some places, like the Snake River Canyon near Twin Falls (below)

12. On the eastern edge of the SRP is found the Grand Canyon of the Snake River.

13. The deepest, most rugged part is called Hell’s Canyon, the deepest gorge in North America, 8000 feet below the surrounding mountain peaks

15. Hell’s Canyon lies at the foot of the Seven Devils Mountains (count them)!

16. Lewiston (L) and Clarkston (R) lie at the confluence of the Snake (back) and the Clearwater (bottom) Rivers

18. Lost River Range • Lost River Sinks

19. The Lost Rivers flow out of the valleys of the Lost River Range and disappear into the ground of the Plain

20. The waters become part of the Eastern Snake River Plain Aquifer flowing to the Snake River on the west

23. The Snake and tributaries used to flood regularly through thousands of years

24. Now, dam systems control the flow

25. And create opportunities for agriculture

26. SRP Formation • Volcanic activity • Water erosion • Sedimentation

27. Fissure flows

28. Leading to layered basalt formations

29. Numerous cinder cones (buttes)

30. And every volcanic formation you can think of located at

31. Located in the east-central part of the plain in a triangular area formed by Arco, Idaho Falls and Pocatello

32. There are many self-guided tours of the site as well as an interpretive center

33. pahoehoe Cinder cones Aa Lava tubes

34. The Yellowstone Hot Spot is responsible for the heat that created all this volcanism

35. Water is down in the summerdue to irrigation demands

36. Flooding is no longer a problem due to……

37. A series of dams to control flooding, create recreation, and provide irrigation water On June 6, 1976 the Teton Dam near Rexburg, Idaho failed during its initial filling.  At 350 feet high, it was the largest dam break in US history and the damages reached $1 billion.

38. After the breach

39. This water has increased the value of the mixed volcanic-sediment soil to…….

40. Idaho Agriculture

41. Climate • Mild and pleasant • Summers sunny and warm with few cloudy days; winters cool and dry • Precipitation averages 10 inches (25cm); semi-arid (quick thundershowers) • Summer temp.= 81degrees (105 max) with cool evenings • Winter temp.=13-35 degrees with snow in the mountains surrounding

42. From space

43. End of the road!