Download Rocks - Macmillan Learning

Classroom presentations
to accompany
Understanding Earth, 3rd edition
prepared by
Peter Copeland and William Dupré
University of Houston
Chapter 3
Rocks: Records of Geologic Processes
Rocks:
Rocks:
Records
Records of
of Geologic
Geologic
Processes
Processes
Three types of rocks
Igneous
Sedimentary
Metamorphic
Igneous rocks make up most of the earth
sedimentary rocks make up most of the
surface.
Major Rock Groups
IGNEOUS
SEDIMENTARY
METAMORPHIC
Fig. 3.1
Igneous Rocks
Rocks formed from the cooling
and consolidation of magma.
Fig. 3.2
Intrusive
Granite
Fig. 3.2
Extrusive
Basalt
Fig. 3.2
Intrusive Granite
Fig. 3.2
Extrusive Basalt
Fig. 3.2
Sedimentary Rocks
Rocks formed by the consolidation of
fragments of previously existing rock
or chemically precipitated from
solution.
From Weathering to Sedimentary Rock
Fig. 3.3
Genesis of Sedimentary Rocks
• Physical weathering: reduction in
size
• Chemical weathering: change in
composition
• Transportation:
–Solid particles ... clastics by water,
wind, ice
–Ions in solution ... chemical
How common are sedimentary
rocks?
Fig. 3.4
Metamorphic rocks
Rocks whose original form has
changed in the solid state due to
increased temperature and/or
pressure.
Where does Metamorphism occur?
Regional Metamorphism
Fig. 3.5
Where does Metamorphism occur?
Regional Metamorphism
Contact Metamorphism
Fig. 3.5
Where we see rocks
• Outcrops
• Drilling
Outcrop
Fig. 3.6
Fred Hirschmann
Fig. 3.7
Russ Kinne/ Comstock
Fig. 3.8
Carr Clifton
Fig. 3.9
The
Rock
Cycle
Fig. 3.10
Plate tectonics
and the rock cycle
The production and destruction of
rocks is ultimately related to plate
tectonics.
Subduction at
convergent plate
boundaries
causes partial
melting to form
magma and
resulting igneous
rocks.
Fig. 3.11a
Magma
rises from
the mantle
at divergent
plate
boundaries.
Fig. 3.11b
Subsidence at
rifted plate
margin allows
for the
deposition,
burial, and
lithification
of sediments.
Fig. 3.11c
Plate interiors
are dominated by
sedimentary
processes, with
some volcanism
due to mantle
“hot spots.”
Fig. 3.11d
Convergence of
plates causes
deformation,
uplift, and
regional
metamorphism.
Fig. 3.11e