1. Rock Structures Mt. St. Helens, October 2004

2. Igneous Structures: Plutons, Volcanoes, & Lava Flows (Oh, My!)

3. Plutons

4. Name this Igneous Feature… Igneous Dike

5. Plutonic Structures Xenoliths Source: William E. Ferguson

6. Why do we find Plutons at the Surface? Sierra Nevada Mountains Batholith, California Uplift & Erosion

7. Volcanic Structures Mafic vs. Intermediate/Felsic

8. Mafic Eruptions: Passive Lava Flows

9. Lava Flows

10. Aa Lava Flows

11. Pahoehoe Lava Flows

12. “Window” into Lava Tube

13. Lava Tubes

14. Pillow Structure

15. Pillow Structures

16. Columnar Structures

17. Shield Volcano

18. Summit Caldera

19. Cinder Cones

20. Flood Basalt Flows

21. Felsic Eruptions: Explosive Ash and Thick Lava Flows

22. Stratovolcano

23. Lava Dome

24. Ash Flow Caldera

25. Ash-Flow Caldera: Crater Lake, Oregon

26. Pyroclastic Flow

28. Sedimentary Structures

29. Stratafication Bedding (1-300 cm) Laminations (<1 cm) Massive Strata (>300 cm)

30. Inter-Bed Structures (within strata) Graded Beds Cross Beds Dropstones Outcrop of turbidites, Carboniferous, northwestern China.

31. Graded Beds Death Valley, CA

33. Cross Beds Zion National Park, UT

34. Dropstones Norway

35. Intra-Bed Structures (on the surface of strata) Ripple Marks Mudcracks Raindrop Impressions

36. Ripple Marks

37. Mudcracks Glacier National Park, MT

38. Raindrop Impressions

39. Fossils

40. Trace Fossils Worm Burrows: Middle Silurian, Grimsby Formation, Hamilton, Ontario Coprolites Miocene Mammal (WA)