1. Geology of the Grand Canyon
Bob Leighty
GLG Physical Geology

2. These notes and web links are your primary “lecture” content in this class. Additionally, various articles are assigned each week to supplement this “lecture” information. I believe you’ll have enough information to reference without having to purchase a costly textbook.
These lecture notes are very similar to the ones I use in my traditional classes. You’ll find they are loaded with imagery and streamlined text that highlight the most essential terms and concepts. The notes provide a framework for learning and, by themselves, are not meant to be a comprehensive source of information.
To take advantage of the global knowledge base known as the Internet, I have included numerous hyperlinks to external web sites (like the Wikipedia, USGS, NASA, etc.). Follow the links and scan them for relevant info. The information from linked web sites is meant to supplement and reinforce the lecture notes – you won’t be responsible for knowing everything contained in them.
As a distance learning student, you need to explore and understand the content more independently than in a traditional class. As always, I will help guide you through this learning adventure. Remember, Dr. Bob if you have any questions about today’s lecture
Leave no questions behind!
Explore and have fun!

3. Grand Canyon
Physiography
WWW
Location Map

4. Uinkaret volcanic field
Physiography
Grand Canyon
Digital relief map of the Grand Canyon region (dark green are lower elevations, light green are higher elevations)
Lees Ferry
EASTERN
WESTERN
Phantom Ranch
Kaibab Upwarp
Uinkaret volcanic field
LCR
Grand Wash Cliffs
Havasu Canyon
South Rim
Desert View
Diamond Creek

5. Grand Canyon
Physiography
limestone
sandstone
In arid climates, sedimentary rock types that are resistant to weathering (e.g., limestone & sandstone) form cliffs . . .
mudstone
. . . and ones that are NOT resistant to weathering (e.g., mudstone) form slopes

6. WWW Geologic Time missing missing Paleozoic sedimentary rocks
Grand Canyon
WWW
Paleozoic sedimentary rocks
Grand Canyon Supergroup
Yavapai Supergroup + Intrusives
missing
missing

7. Stratigraphy
Grand Canyon
WWW
Proterozoic igneous & metamorphic rocks underlie nearly flat-lying Paleozoic sedimentary rocks

8. Early Proterozoic Rocks Yavapai Supergroup (~1750 Ma)
Grand Canyon
Early Proterozoic Rocks
Yavapai Supergroup (~1750 Ma)
Metamorphic rocks (Xm) exposed in the Inner Gorge
> Vishnu Schist (Xms; metasedimentary)
Xms
> Rama Schist & Gneiss (Xmv; felsic metavolcanics)
> Brahma Schist (Xmv; mafic metavolcanics)
Xmv

9. Early Proterozoic Rocks Intrusive Igneous Rocks (1840-1660 Ma)
Grand Canyon
Intrusive Igneous Rocks ( Ma)
Mostly granitic-dioritic rocks exposed in the Inner Gorge
Xgd Xg
> Elves Chasm Granodiorite (Xgd; 1840 Ma = oldest in AZ)
> Zoroaster Granite, etc. (Xg; Ma)

10. Early Proterozoic Rocks Intrusive Igneous Rocks (1840-1660 Ma)
Grand Canyon
Intrusive Igneous Rocks ( Ma)
Granitic intrusions in the Inner Gorge Xg

11. Middle & Late Proterozoic Rocks Grand Canyon Supergroup (1250-800 Ma)
Mostly sedimentary rocks and basaltic flows & sills Ys

12. Middle & Late Proterozoic Rocks Grand Canyon Supergroup (1250-800 Ma)
Unkar Group ( Ma)
Bass Limestone, Hakatai Shale, Shinumo Quartzite, Dox Sandstone (Ys) Ys
Basaltic lava flows, diabase sills & dikes (Yd; ~1100 Ma)

13. Middle & Late Proterozoic Rocks Grand Canyon Supergroup (1250-800 Ma)
Unkar Group ( Ma)
Cardenas mafic dike intrudes reddish Hakatai Shale at Hance Rapids Ys Yd

14. Middle & Late Proterozoic Rocks Grand Canyon Supergroup (1250-800 Ma)
Chuar Group (~ Ma)
Organic-rich shallow marine mudstones (Zs) Zs

15. Grand Canyon
Paleozoic Rocks
All sedimentary rocks

16. Tapeats Sandstone (Cambrian)
Grand Canyon
Paleozoic Rocks
Tapeats Sandstone (Cambrian)
Cliff-forming nearshore shallow marine sandstone (Ct)

17. Tapeats Sandstone (Cambrian)
Grand Canyon
Paleozoic Rocks
Tapeats Sandstone (Cambrian)
View west from Skeleton Point of Pipe Creek and Plateau Point
PlateauPoint Ct
Xg & Xm

18. Bright Angel Shale (Cambrian)
Grand Canyon
Paleozoic Rocks
Bright Angel Shale (Cambrian)
Slope-forming shallow to deep marine mudstone (Cba)
Cba

19. Bright Angel Shale (Cambrian)
Grand Canyon
Paleozoic Rocks
Bright Angel Shale (Cambrian)
Bright Angel Shale exposed along the Bright Angel Trail near Indian Gardens
Cba

20. Muav Limestone (Cambrian)
Grand Canyon
Paleozoic Rocks
Muav Limestone (Cambrian)
Cliff-forming shallow to deep marine limestone (Cm) Cm

21. Muav Limestone (Cambrian)
Grand Canyon
Paleozoic Rocks
Muav Limestone (Cambrian)
Muav Limestone exposed along the Bright Angel Trail near Indian Gardens Cm

22. “Cheops Bay” across from Plateau Point.
Paleozoic Rocks
Grand Canyon
“Islands” of Precambrian rock (Y) in the Cambrian sea
“Cheops Bay” across from Plateau Point.
The older rocks (Y) were higher when the younger rocks (Є) were deposited in a shallow ocean. Y C

23. Temple Butte Limestone (Devonian)
Paleozoic Rocks
Grand Canyon
Temple Butte Limestone (Devonian)
Temple Butte channel in Marble Canyon
Stream channel-filling limestone (Dtb) Cm Mr
Dtb channel

24. Redwall Limestone (Mississippian)
Grand Canyon
Paleozoic Rocks
Redwall Limestone (Mississippian)
Cliff-forming shallow marine limestone (Mr) Mr

25. Redwall Limestone (Mississippian)
Grand Canyon
Paleozoic Rocks
Redwall Limestone (Mississippian)
Redwall alcove above Stephen Aisle Mr

26. Supai Group (Pennsylvanian-Permian)
Grand Canyon
Paleozoic Rocks
Supai Group (Pennsylvanian-Permian)
Cliff & slope-forming river delta, flood plain, desert dune, & shallow marine sediments (PPs)
PPs

27. Supai Group (Pennsylvanian-Permian)
Grand Canyon
Paleozoic Rocks
Supai Group (Pennsylvanian-Permian)
Supai Group rocks exposed below Zoroaster Temple
PPs

28. Hermit Shale (Permian)
Grand Canyon
Paleozoic Rocks
Hermit Shale (Permian)
Slope-forming river delta & flood plain mudstone (Ph) Ph

29. Hermit Shale (Permian)
Grand Canyon
Paleozoic Rocks
Hermit Shale (Permian)
Hermit Shale exposed in Marble Canyon Ph

30. Coconino Sandstone (Permian)
Grand Canyon
Paleozoic Rocks
Coconino Sandstone (Permian)
Cliff-forming eolian (wind-deposited) sandstone (Pc) Pc

31. Coconino Sandstone (Permian)
Grand Canyon
Paleozoic Rocks
Coconino Sandstone (Permian)
Sheer cliffs of Coconino Sandstone below Mather Point Pc

32. Toroweap Formation (Permian)
Grand Canyon
Paleozoic Rocks
Toroweap Formation (Permian)
Slope-forming unit composed of sandstone, dolomite, etc. (Pt) Pt

33. Toroweap Formation (Permian)
Grand Canyon
Paleozoic Rocks
Toroweap Formation (Permian)
Three members of the Toroweap Formation below Mather Point
Ptw
Ptb
Pts
Ptw = Woods Ranch Member
Ptb = Brady Canyon Member
Pts = Seligman Member

34. Kaibab Formation (Permian)
Grand Canyon
Paleozoic Rocks
Kaibab Formation (Permian)
Cliff-forming shallow marine dolomite & limestone (Pk) Pk

35. Kaibab Formation (Permian)
Grand Canyon
Paleozoic Rocks
Kaibab Formation (Permian)
The Kaibab Formation at Mather Point Pk

36. Moenkopi & Chinle Formations (Triassic)
Grand Canyon
Mesozoic Rocks
Moenkopi & Chinle Formations (Triassic)
Sedimentary rocks locally exposed as erosional remnants
T m
T c
Moenkopi and Chinle exposed at Cedar Mountain east of Desert View

37. Uinkaret volcanic field (Plio-Pleistocene; 4 to <1 Ma)
Cenozoic Rocks
Grand Canyon
Uinkaret volcanic field (Plio-Pleistocene; 4 to <1 Ma)
Tby, QTb - Basaltic cones and flows
Vulcans Throne
Lava dams created large lakes
Recreation of the one of the highest lava-dam lakes Qb

38. Uinkaret volcanic field (Plio-Pleistocene; 4 to <1 Ma)
Grand Canyon
Cenozoic Rocks
Uinkaret volcanic field (Plio-Pleistocene; 4 to <1 Ma)
Lava cascades at Vulcans Throne
Lava-filled stream channel at Whitmore Wash Qb

39. Landslides & Rockfalls (Pleistocene to Recent; <2 Ma)
Cenozoic Rocks
Grand Canyon
Landslides & Rockfalls (Pleistocene to Recent; <2 Ma)
Rockfall talus in Marble Canyon Qt
Surprise Valley landslide at Deer Creek
Qls

40. Proterozoic Tectonics
Grand Canyon
Proterozoic Tectonics
Yavapai Orogeny ( Ma)
Subduction-related compression, with metamorphism, faulting, and folding

41. Phanerozoic Tectonics
Grand Canyon
Laramide Orogeny (Late Cretaceous to Early Tertiary)
Late Mesozoic/Early Cenozoic compression due to low-angle subduction
Reverse faulting forms monoclines across the Colorado Plateau

42. Phanerozoic Tectonics Regional Uplift & Extension (Late Tertiary)
Grand Canyon
Regional Uplift & Extension (Late Tertiary)
Late Tertiary extension creates high-angle normal faults
<6 Ma, regional uplift causes stream downcutting & forms the Canyon

43. WWW Links in this Lecture
Grand Canyon
> Grand Canyon -
> Geologic time -
> Grand Canyon Stratigraphy -
> Basin and Range -
> Colorado Plateau -