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

Cross-cutting relationships: dike cutting gneiss is youngerN. Lindsley-Griffin, 1998

Cross-cutting relationships: dike cutting gneiss is youngerN. Lindsley-Griffin, 1998

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

Superposition

Disconformity

Original horizontality

Angular unconformity

Cross-cutting relationships

Nonconformity

Grand Canyon FormationsGrand Canyon Formations

© Houghton Mifflin 1998. All rights reserved

Grand Canyon FormationsGrand Canyon Formations

© Houghton Mifflin 1998. All rights reserved

Sequence of events based on geology of the Inner Gorge

1.Deposition of shale in marine environment

2. Metamorphism of shale into Vishnu schist

3. Intrusion by Zoroaster granite

4. Erosion to sea level, unconformity surface

5. Deposition of Grand Canyon Supergroup

6. Faulting 7. Erosion of fault blocks, deposition of Tapeats sandstone

Geologic Time - SummaryGeologic Time - Summary

N. Lindsley-Griffin, 1999

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