Download Limestone

The Grand Canyon
Tells the Story of North America
 Knowing how and where rocks are
formed allows us to read the story
written in the rocks.
 A mile thickness of rocks of the Great
Plains are exposed by uplift and erosion
by the Colorado River.
Rocks of the
Grand Canyon
Separate the larger puzzle into
a series of smaller puzzles
(I.e., each group of rocks)
 Metamorphic rocks (oldest)
 Intrusive igneous rocks
 Sedimentary rocks lying on an
irregular metamorphic surface
 Sedimentary layering
 Erosion of the canyon (Youngest event)
Rocks of the
Grand Canyon
Each group of rocks is separated by a gap
in the geologic record (formations and
contacts)





Metamorphic rocks  Metamorphism
Granite  Intrusion of silicic magma
Eroded surface  Uplift and erosion
Sedimentary rocks  Shallow inland seas
Erosion of the Canyon  Recent uplift
Metamorphic and
Igneous Rocks


Metamorphism of
sedimentary rocks
Igneous intrusion
during later stages
of metamorphism
(during mountain
building)

Uplift and erosion
(during and after
mountain building)
(nonconformity)
Sedimentary Rocks



Deposition of sediments
on eroded metamorphic
and igneous rocks.
Uplift and erosion
exposing sedimentary
layers and
Eventually expose
Igneous and
metamorphic rocks again
G Uplift and
Renewed
Erosion
Erosion and Exposure


Uplift and erosion
exposing sedimentary
layers and
Eventually Igneous and
metamorphic rocks again
G Uplift and
Renewed
Erosion
G Uplift and
Renewed
Erosion
Formation of the
Grand Canyon
Sandstone
Shale
Limestone
350
380
450
Million Years Old
300
million years ago
Formation of the
Grand Canyon
1. Regional Uplift,
Tilting (or folding),
Erosion
Erosion
Sandstone
Shale
Limestone
350
380
450
280
million years ago
Regional Uplift
Tilting (or folding)
Formation of the
Grand Canyon
1. Regional Uplift,
Tilting (or folding),
Erosion
Erosion
Sandstone
Shale
Limestone
350
380
450
270
million years ago
Regional Uplift
Formation of the
Grand Canyon
1. Regional Uplift,
Tilting (or folding),
Erosion
Erosion
Sandstone
Shale
Limestone
350
380
450
260
million years ago
Regional Uplift
Formation of the
Grand Canyon
1. Regional Uplift,
Tilting (or folding),
Erosion
Erosion
Sandstone
Shale
Limestone
350
380
450
250
million years ago
Regional Uplift
1. Regional Uplift,
Tilting, or folding)
causes Erosion
2. Erosion surface
indicates gap in
geologic record
Formation of the
Grand Canyon
Sandstone 350
Shale 380
Limestone
450
Gneiss (1,500)
Granite (280)
Gabbro (790)
240
million years ago
1. Regional Uplift,
Tilting (or folding),
Erosion
2. Erosion surface,
gap in geologic
record
3. Continuous
Sedimentation
Formation of the
Grand Canyon
Sedimentation (e.g., clay)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
220
million years ago
1. Regional Uplift,
Tilting (or folding),
Erosion
2. Erosion surface,
gap in geologic
record
3. Continuous
Sedimentation
Formation of the
Grand Canyon
Sedimentation (e.g., lime mud)
Shale (220)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
210
million years ago
1. Regional Uplift,
Tilting (or folding),
Erosion
2. Erosion surface,
gap in geologic
record
3. Continuous
Sedimentation
Formation of the
Grand Canyon
Sedimentation (e.g., quartz sand)
Limestone
(210)
Shale (220)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
200
million years ago
1. Regional Uplift,
Tilting (or folding),
Erosion
2. Erosion surface,
gap in geologic
record
3. Continuous
Sedimentation
Formation of the
Grand Canyon
Quartz Sandstone
(200)
Limestone
(210)
Shale (220)
Sedimentation (e.g., immature sand)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
190
million years ago
1. Regional Uplift,
Tilting (or folding),
Erosion
2. Erosion surface,
gap in geologic
record
3. Continuous
Sedimentation
Formation of the
Grand Canyon
Quartz Sandstone
(200)
Limestone
(210)
Shale (220)
Arkose
(190)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
180
million years ago
1. Regional Uplift,
Tilting (or folding),
Erosion
2. Erosion surface,
gap in geologic
record
3. Continuous
Sedimentation
4. Sedimentation
ceases
Formation of the
Grand Canyon
Quartz Sandstone
(200)
Limestone
(210)
Shale (220)
Arkose
(190)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
170
million years ago
Formation of the
1. Erosion of horizontal beds
Grand Canyon
Quartz Sandstone
(200)
Limestone
(210)
Shale (220)
Arkose
(190)
Erosion
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
160
million years ago
Formation of the
Grand Canyon
Quartz Sandstone
(200)
Limestone
(210)
Shale (220)
Arkose
(190)
1. Erosion of horizontal beds
2. Loss of geologic record
(i.e., Arkose)
3. Formation of a horizontal
erosion surface
Erosion
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
150
million years ago
Formation of the
Grand Canyon
Quartz Sandstone
(200)
Limestone
(210)
Shale (220)
1. Erosion of horizontal beds
2. Loss of geologic record
(i.e., Arkose)
3. Formation of a horizontal
erosion surface
4. Renewed Sedimentation
Arkose
Sedimentation (e.g., reef)
(190)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
140
million years ago
Formation of the
Grand Canyon
Quartz Sandstone
(200)
Limestone
(210)
Shale (220)
1. Erosion of horizontal beds
2. Loss of geologic record
(i.e., Arkose)
3. Formation of a horizontal
erosion surface
4. Renewed Sedimentation
Arkose
(190)
Limestone (140)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (280)
Gabbro (790)
130
million years ago
Formation of the
Grand Canyon
Quartz Sandstone
(200)
Limestone
(210)
Shale (220)
1. Erosion of horizontal beds
2. Loss of geologic record
(i.e., Arkose)
3. Formation of a horizontal
erosion surface
4. Renewed Sedimentation
Arkose
(190)
Limestone (140)
Sandstone 350
Shale 380
Limestone 450
Gneiss (1,500)
Granite (290)
Gabbro (790)
120
million years ago
Formation of the
Grand Canyon

Deciphering Relative
Ages


Limestone
Quartz
Sandstone
Limestone
Shale
Sandstone
Shale
Limestone
Principles give
sequences of geologic
events
Unconformities
indicate gaps in the
geologic record
Disconformity
Angular
Unconformity
Gneiss
Granite
Gabbro
Nonconformities
Uplift and Erosion



As the land is lifted
up by tectonic
forces
A stream will
attempt to maintain
its base level by
Cutting down into
the rocks due to
accelerated
erosion
The Grand Staircase
Eastern Zion National Park