GLG 101 - Physical Geology Bob Leighty Geology of the Grand Canyon.

GLG 101 - Physical GeologyGLG 101 - Physical Geology Bob LeightyBob Leighty

Geology of the Geology of the Grand CanyonGrand Canyon

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, email Dr. Bob if you have any questions about today’s lecture ([email protected]).Leave no questions behind!

Explore and have fun!Explore and have fun!

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.

mailto:[email protected]

Location Map

PhysiographyPhysiographyGrandGrand

CanyonCanyon

http://en.wikipedia.org/wiki/Grand_Canyon

Digital relief map of the Grand Canyon region(dark green are lower elevations, light green are higher elevations)

Kaib

ab U

pw

arp

Lees Ferry

South Rim

LCR

Uinkaret volcanic field

EASTERNWESTERN

Havasu

CanyonG

ran

d W

ash

Clif

fs

DesertView

PhantomRanch

DiamondCreek


CanyonCanyon

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


CanyonCanyon

Geologic TimeGeologic TimeGrandGrand

CanyonCanyon

Yavapai Supergroup + Intrusives

Grand Canyon SupergroupPaleozoic

sedimentary rocks

missingmissing

missing

mis

sin

g

mis

sin

g

mis

sin

g

StratigraphyStratigraphyGrandGrand

CanyonCanyon

Proterozoic igneous & metamorphic rocks underlienearly flat-lying Paleozoic sedimentary rocks

> Rama Schist & Gneiss (Xmv; felsic metavolcanics)

Metamorphic rocks (Xm) exposed in the Inner Gorge

Yavapai SupergroupYavapai Supergroup(~1750 Ma)(~1750 Ma)

> Vishnu Schist (Xms; metasedimentary)

Xms

> Brahma Schist (Xmv; mafic metavolcanics)

Xmv

Early Proterozoic RocksEarly Proterozoic RocksGrandGrand

CanyonCanyon

Intrusive Igneous RocksIntrusive Igneous Rocks(1840-1660 Ma)(1840-1660 Ma)

> Zoroaster Granite, etc.

(Xg; 1740-1660 Ma)

> Elves Chasm Granodiorite

(Xgd; 1840 Ma = oldest in AZ)

Mostly granitic-dioritic rocks exposed in the Inner Gorge

Xgd

Xg


CanyonCanyon

Intrusive Igneous RocksIntrusive Igneous Rocks(1840-1660 Ma)(1840-1660 Ma)

Granitic intrusions in the Inner Gorge

Xg Xg


CanyonCanyon

Grand Canyon SupergroupGrand Canyon Supergroup(1250-800 Ma)(1250-800 Ma)

Mostly sedimentary rocks and basaltic flows & sills

Ys

Ys

Middle & Late Proterozoic RocksMiddle & Late Proterozoic RocksGrandGrand

CanyonCanyon

Unkar GroupUnkar Group(1250-1070 Ma)(1250-1070 Ma)

Basaltic lava flows, diabase sills & dikes (Yd; ~1100 Ma)

Bass Limestone, Hakatai Shale, Shinumo Quartzite, Dox

Sandstone (Ys)

Ys



CanyonCanyon

Cardenas mafic dike intrudes reddish Hakatai Shale at Hance Rapids

Ys

Yd

Unkar GroupUnkar Group(1250-1070 Ma)(1250-1070 Ma)



CanyonCanyon

Chuar GroupChuar Group(~900-825 Ma)(~900-825 Ma)

Organic-rich shallow marine mudstones (Zs)

Zs



CanyonCanyon

All sedimentary rocks

Paleozoic RocksPaleozoic RocksGrandGrand

CanyonCanyon

Cliff-forming nearshore shallow marine sandstone (Ct)

Tapeats SandstoneTapeats Sandstone(Cambrian)(Cambrian)


CanyonCanyon

View west from Skeleton Point of Pipe Creek and Plateau Point

PlateauPoint

Ct

Ct

Xg & Xm

Tapeats SandstoneTapeats Sandstone(Cambrian)(Cambrian)


CanyonCanyon

Slope-forming shallow to deep marine mudstone (Cba)

Cba

Bright Angel ShaleBright Angel Shale(Cambrian)(Cambrian)


CanyonCanyon

Bright Angel Shale exposed along the Bright Angel Trail near Indian Gardens

Cba

Bright Angel ShaleBright Angel Shale(Cambrian)(Cambrian)


CanyonCanyon

Cliff-forming shallow to deep marine limestone (Cm)

Cm

Muav LimestoneMuav Limestone(Cambrian)(Cambrian)


CanyonCanyon

Muav Limestone exposed along the Bright Angel Trail near Indian Gardens

Cm

Muav LimestoneMuav Limestone(Cambrian)(Cambrian)


CanyonCanyon

“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

C


CanyonCanyon

Temple Butte LimestoneTemple Butte Limestone(Devonian)(Devonian)

Temple Butte channel in Marble Canyon

Stream channel-filling limestone (Dtb)

Cm

Mr

Dtb channel


CanyonCanyon

Redwall LimestoneRedwall Limestone(Mississippian)(Mississippian)

Cliff-forming shallow marine limestone (Mr)

Mr


CanyonCanyon

Redwall alcove above Stephen Aisle

Mr

Redwall LimestoneRedwall Limestone(Mississippian)(Mississippian)


CanyonCanyon

Supai GroupSupai Group(Pennsylvanian-Permian)(Pennsylvanian-Permian)

Cliff & slope-forming river delta, flood plain, desert dune,

& shallow marine sediments (PPs)

PPs


CanyonCanyon

Supai Group rocks exposed below Zoroaster Temple

Supai GroupSupai Group(Pennsylvanian-Permian)(Pennsylvanian-Permian)


CanyonCanyon

PPs

Hermit ShaleHermit Shale(Permian)(Permian)

Slope-forming river delta & flood plain mudstone (Ph)

Ph


CanyonCanyon

Hermit Shale exposed in Marble Canyon

Ph

Hermit ShaleHermit Shale(Permian)(Permian)


CanyonCanyon

Coconino SandstoneCoconino Sandstone(Permian)(Permian)

Cliff-forming eolian (wind-deposited) sandstone (Pc)

Pc


CanyonCanyon

Sheer cliffs of Coconino Sandstone below Mather Point

Coconino SandstoneCoconino Sandstone(Permian)(Permian)


CanyonCanyon

Pc

Toroweap FormationToroweap Formation(Permian)(Permian)

Slope-forming unit composed of sandstone, dolomite, etc. (Pt)

Pt


CanyonCanyon

Three members of the Toroweap Formation below Mather Point

Ptw

PtbPts

Ptw = Woods Ranch Member

Ptb = Brady Canyon Member

Pts = Seligman Member

Toroweap FormationToroweap Formation(Permian)(Permian)


CanyonCanyon

Kaibab FormationKaibab Formation(Permian)(Permian)

Cliff-forming shallow marine dolomite & limestone (Pk)

Pk


CanyonCanyon

The Kaibab Formation at Mather Point

Kaibab FormationKaibab Formation(Permian)(Permian)


CanyonCanyon

Pk

Moenkopi & Chinle FormationsMoenkopi & Chinle Formations(Triassic)(Triassic)

Sedimentary rocks locally exposed as erosional remnants

T m

T c

Moenkopi and Chinle exposed at Cedar Mountain east of Desert View

Mesozoic RocksMesozoic RocksGrandGrand

CanyonCanyon

Tby, QTb - Basaltic cones and flows

Vulcans Throne

Uinkaret volcanic fieldUinkaret volcanic field(Plio-Pleistocene; 4 to <1 Ma)(Plio-Pleistocene; 4 to <1 Ma)

Lava dams created large lakes

Recreation of the one of the highest lava-dam lakes

Qb

Cenozoic RocksCenozoic RocksGrandGrand

CanyonCanyon

Lava cascades at Vulcans Throne

Lava-filled stream channel at Whitmore Wash

QbQb

Uinkaret volcanic fieldUinkaret volcanic field(Plio-Pleistocene; 4 to <1 Ma)(Plio-Pleistocene; 4 to <1 Ma)


CanyonCanyon

Landslides & RockfallsLandslides & Rockfalls(Pleistocene to Recent; <2 Ma)(Pleistocene to Recent; <2 Ma)

Rockfall talus in Marble Canyon

Qt

Qt

Surprise Valley landslide at Deer Creek

Qls

Qls


CanyonCanyon

Yavapai OrogenyYavapai Orogeny(1710-1700 Ma)(1710-1700 Ma)

Subduction-related compression, with metamorphism, faulting, and folding

Proterozoic TectonicsProterozoic TectonicsGrandGrand

CanyonCanyon

Laramide OrogenyLaramide Orogeny(Late Cretaceous to Early Tertiary)(Late Cretaceous to Early Tertiary)

Late Mesozoic/Early Cenozoic compression due to low-angle subduction

Reverse faulting forms monoclines across the Colorado Plateau

Phanerozoic TectonicsPhanerozoic TectonicsGrandGrand

CanyonCanyon

<6 Ma, regional uplift causes stream downcutting & forms the Canyon

Regional Uplift & ExtensionRegional Uplift & Extension(Late Tertiary)(Late Tertiary)

Late Tertiary extension creates high-angle normal faults

Phanerozoic TectonicsPhanerozoic TectonicsGrandGrand

CanyonCanyon

WWW Links in this LectureWWW Links in this Lecture

> Grand Canyon - http://en.wikipedia.org/wiki/Grand_Canyon

> Geologic time - http://www.stratigraphy.org/geowhen/timelinestages.html

> Grand Canyon Stratigraphy -

http://3dparks.wr.usgs.gov/coloradoplateau/grandcanyon_strat.htm

> Basin and Range - http://en.wikipedia.org/wiki/Basin_and_Range_Province

> Colorado Plateau - http://en.wikipedia.org/wiki/Colorado_Plateau

Grand Grand

CanyonCanyon

GLG 101 - Physical Geology Bob Leighty Geology of the Grand Canyon.

Documents

Transcript of GLG 101 - Physical Geology Bob Leighty Geology of the Grand Canyon.