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[Illustration: Geology of Arches National Park]
[Illustration: BALANCED ROCK, guarding The Windows section of Arches National Park. Rock is Slick Rock Member of Entrada Sandstone resting upon crinkly bedded Dewey Bridge Member of the Entrada. White rock in foreground is Navajo Sandstone. La Sal Mountains on right skyline. (Frontispiece)]
_The Geologic Story of_ Arches NATIONAL PARK
By S. W. Lohman Graphics by John R. Stacy
UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, _Secretary_
GEOLOGICAL SURVEY V. E. McKelvey, _Director_
[Illustration: Department of the Interior · March 3, 1949]
Library of Congress Cataloging in Publication Data Lohman, Stanley William, 1907- The geologic story of Arches National Park. (Geological Survey Bulletin 1393) Bibliography: p. Includes index. Supt. of Docs. no.: I 19.3:1393 1. Geology--Utah--Arches National Park--Guide-books. 2. Arches National Park, Utah--Guide-books. I. Title. II. Series: United States Geological Survey Bulletin 1393. QE75.B9 No. 1393 [QE170.A7] 557.3'08s [557.92'58] 74-23324
For sale by the Superintendent of Documents, U. S. Government Printing Office Washington, D. C. 20402 Stock Number 024-001-02598-1
Page Beginning of a monument 1 Graduation to a park 5 Early history 9 Prehistoric people 9 Late arrivals 12 Geographic setting 18 Deposition of the rock materials 20 Bending and breaking of the rocks 24 Uplift and erosion of the Plateau 33 Origin and development of the arches 37 Examples of arches 46 How to see the park 50 A trip through the park 52 Colorado River canyon 52 Headquarters area 57 Courthouse Towers area 63 The Windows section 68 Delicate Arch area 74 Fiery Furnace 79 Salt Valley and Klondike Bluffs 82 Devils Garden 83 Summary of geologic history 98 Additional reading 104 Acknowledgments 105 Selected references 105 Index 109
Page Frontispiece. Balanced Rock. 1. Arches National Park 6 2. Rock art in Arches National Park 11 3. Wolfe's Bar-DX Ranch 14 4. Rock column of Arches National Park 21 5. Common types of rock folds 25 6. Common types of rock faults 26 7. Paradox basin 27 8. Geologic section across northwest end of Arches National Park 28 9. Index map of northwestern part of Arches National Park 28 10. Gravity anomalies over Salt Valley 31 11. Tilted block of rocks in Cache Valley graben 34 12. Jointed northeast flank of Salt Valley anticline 36 13. Index map 38 14. Tunnel Arch 43 15. "Baby Arch" 44 16. Broken Arch 45 17. Double Arch 47 18. Pothole Arch 48 19. Glen Canyon Group 53 20. Navajo Sandstone cliffs 54 21. Mouth of Salt Wash 55 22. Southeast end of faulted Cache Valley anticline 56 23. Faulted Seven Mile-Moab Valley anticline 58 24. Three Penguins 59 25. Moab Valley 60 26. Faulted wall of Entrada Sandstone 61 27. Park Avenue 62 28. Balanced rocks on south wall of Park Avenue 64 29. Courthouse Towers 65 30. The Three Gossips 66 31. Sheep Rock 66 32. Petrified sand dunes 67 33. "Hoodoos and goblins" 68 34. Eye of The Whale 69 35. Intricate crossbeds in Navajo Sandstone 70 36. Cove Arch and Cove of Caves 71 37. North Window 72 38. Looking southwestward through North Window 73 39. South Window 74 40. Turret Arch 75 41. Parade of Elephants 76 42. Suspension foot bridge across Salt Wash 78 43. Delicate Arch 78 44. Fiery Furnace 80 45. Trail to Sand Dune Arch 81 46. Sand Dune Arch 82 47. Tower Arch 84 48. Skyline Arch 85 49. Campground in Devils Garden 86 50. View north from campground 87 51. Southeastern part of Devils Garden trail 88 52. Pine Tree Arch 89 53. Landscape Arch 91 54. Navajo Arch 92 55. Partition Arch 93 56. Double O Arch 93 57. Dark Angel 94 58. "Indian-Head Arch" 95 59. Geologic time spiral 96