Transcript Do Now:

Do Now: Answer in your NB
Make sure you copy the questions!
What are sediments?
2. List and describe the three types of
sedimentary rocks.
3. How do sedimentary rocks hold evidence
of past life?
4. What are horizontal layers of sedimentary
rocks called?
1.
What do rocks tell us
about the Earth?
Metamorphic Rocks
Form when preexisting rocks are exposed to
increases in temperature and pressure and to
hydrothermal solutions
 Rocks do not reach melting point

Metamorphic Characteristics

Foliated Rocks
 Layers or bands of
minerals
 Minerals with needle
like crystals form with
axes perpendicular to
pressure
Metamorphic Characteristics

Non Foliated Rocks
 Metamorphic rocks composed mainly of
minerals that form blocky crystal shapes
Grades of Metamorphism

Studying metamorphism can
help to locate metamorphic
minerals (such as Garnet)
and interpret metamorphic
history
 Low Grade – Low temp and
pressure
 Intermediate Grade
 High Grade – High temp and
pressure
Types of Metamorphism

Regional Metamorphism
 High temps and pressure affect a large
area creating belts
 Range from high to low grade
 Changes in rocks and minerals
 Deforming of rock layers
Types of Metamorphism

Contact Metamorphism
 Igneous intrusion comes in contact with solid
rock

Hydrothermal Metamorphism
 Very hot water reacts with rock and alters its
chemical and mineral composition
Economic Importance

Construction
 Marble and Slate

Metallic Resources
 Metal Ores (Precipitated
from hydrothermal solutions)

Non Metallic Resources
 Talc, graphite