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Nonconformity - sedimentary rocks over
crystalline (metamorphic or igneous) rocks
N. Lindsley-Griffin, 1998
Nonconformity - sedimentary rocks over
crystalline (metamorphic or igneous) rocks
N. Lindsley-Griffin, 1998
Nonconformity - sedimentary gravels over garnet
schist. What is the history of this outcrop?
N. Lindsley-Griffin, 1998
Nonconformity - sedimentary gravels over garnet
schist. What is the history of this outcrop?
N. Lindsley-Griffin, 1998
N. Lindsley-Griffin, 1998
Cross-cutting relationships:
dike cutting gneiss is younger
N. Lindsley-Griffin, 1998
Cross-cutting relationships:
dike cutting gneiss is younger
Cross cutting relationships: what is the
sequence of events in this folded marble
with two dikes?
N. Lindsley-Griffin, 1998
Cross cutting relationships: what is the
sequence of events in this folded marble
with two dikes?
N. Lindsley-Griffin, 1998
Grand Canyon Formations
Superposition
Disconformity
Original
horizontality
Angular
unconformity
Cross-cutting
relationships
Nonconformity
© Houghton Mifflin 1998. All rights reserved
Grand Canyon Formations
Sequence of events based on geology of the Inner Gorge
1.Deposition of shale in
marine environment
4. Erosion to sea level,
unconformity surface
© Houghton Mifflin 1998. All rights reserved
2. Metamorphism of shale
into Vishnu schist
5. Deposition of Grand
Canyon Supergroup
6. Faulting
3. Intrusion by
Zoroaster granite
7. Erosion of fault blocks,
deposition of Tapeats
sandstone
Geologic Time - Summary
Relative Age -- whether a particular rock or
feature is older or younger than another
Absolute Age -- the age of a rock in years
(m.y. = millions of years)
Geologic Column -- shows succession of all
known strata, in chronological order, based on
fossils and other relative ages
N. Lindsley-Griffin, 1999