Figures
Page [Frontispiece Midway Geyser Basin] II [Plate 1. Geologic map of Yellowstone National Park] 36 [Figure 1. Geographic map of Yellowstone National Park] 2 [2. Index map showing photograph localities] 3 [3. Skyline of the Gallatin Range in northwestern Yellowstone National Park] 6 [4. View north along the Yellowstone River and Hayden Valley toward the Washburn Range] 6 [5. The rocks of Yellowstone National Park] 8 [6. The geologic time scale] 10 [7. View downstream along the Lamar River and closeup view of Precambrian gneiss] 12 [8. Positions of seaways and landmasses during the middle part of Permian time] 14 [9. Crowfoot Ridge in the southern Gallatin Range] 15 [10. Mount Everts] 16 [11. The faunal succession in sedimentary rocks] 17 [12. Beds of limestone along Pebble Creek and closeup views of outcrop and fossils] 18 [13. Common kinds of geologic structures produced by deformation of the earth’s crust] 20 [14. Geologic structures in Yellowstone National Park] 22 [15. Intrusive and extrusive igneous rock bodies] 24 [16. The Absaroka volcanoes and their rocks] 25 [17. Massive beds of volcanic breccia of the Absaroka volcanic rocks and closeup view of outcrop] 26 [18. Massive layered breccias of the Absaroka volcanic rocks at Barronette Peak] 28 [19. Giant petrified tree trunks in Yellowstone’s fossil forest] 29 [20. Closeup view of a specimen of intrusive igneous rock] 30 [21. Bunsen Peak, a body of intrusive igneous rock] 31 [22. Outline of the Yellowstone caldera] 35 [23. Various stages in the development of the Yellowstone caldera] 40 [24. Extent of the rhyolite welded tuffs that once covered Yellowstone National Park] 42 [25. The Yellowstone Tuff at Golden Gate and closeup views of tuff specimens] 43 [26. Cross section through the Mount Washburn-Canyon area, showing relationships along north edge of the Yellowstone caldera] 44 [27. View southeast across Yellowstone Lake toward the Absaroka Range] 45 [28. Radar image of lava flows in southwestern Yellowstone National Park] 46 [29. Obsidian Cliff] 47 [30. Thick rhyolite lava flow along Firehole River and closeup view of specimen] 48 [31. Brecciated lava flows] 49 [32. Outcrop and closeup view of glassy rhyolite lava] 50 [33. Basalt flows at Tower and closeup views of outcrop and specimen] 52 [34. Giant glacial boulder of Precambrian gneiss at Inspiration Point] 54 [35. Glacial terrain along the Northeast Entrance Road] 56 [36. Typical profiles of canyons cut by stream erosion and glaciation] 57 [37. Aerial oblique view of Electric Peak] 58 [38. Extent of ice in Yellowstone National Park during the maximum spreading of the Pinedale glaciers] 60 [39. Beds of sand, silt, and clay deposited in a glacially dammed lake in Hayden Valley] 61 [40. Waterfalls in Yellowstone National Park] 62 [41. Grand Canyon and Lower Falls of the Yellowstone River] 65 [42. Various stages in the development of the Grand Canyon of the Yellowstone] 66 [43. Common kinds of thermal features in Yellowstone National Park] 70 [44. Norris Geyser Basin, showing solid floor of hot spring deposits] 72 [45. Diagram of a thermal system] 72 [46. Infrared image of a portion of Upper Geyser Basin] 73 [47. Mound of geyserite (sinter) at Castle Geyser] 75 [48. Terraces of travertine at Opal Springs and closeup of specimen] 76 [49. Algal-colored terraces lining the west bank of the Firehole River] 78 [50. A geyser in action] 80 [51. Rock rubble surrounding Seismic Geyser in Upper Geyser Basin] 83 [52. Old Faithful in full eruption] 84 [53. Mud volcano near Pocket Basin in Lower Geyser Basin] 86 [54. Reactivation of a fault during the Hebgen Lake earthquake of August 17, 1959] 88