Page 212 - Laboratory Manual in Physical Geology

BIG IDEAS PRE-LAB VIDEO

Metamorphic rocks are rocks that have changed to a new
and different form as a result of intense heat, intense
pressure, and/or the action of watery hot fluids. The
mineralogy and texture of a metamorphic rock can be
used to deduce its original form (parent rock) and infer the
geologic history of how and why it changed. Metamorphic
rocks are widely used in the arts and construction industries
and are sources of industrial minerals and energy.

FOCUS YOUR INQUIRY

|
THINK What do metamorphic rocks look like? How can
About It they be classified into groups?

ACTIVITY 7.1 Metamorphic Rock Inquiry (p. 188 )

THINK What are the characteristics of metamorphic
|
About It rocks, and how are they formed?

ACTIVITY 7.2 Metamorphic Rock Analysis and
Interpretation (p. 189 )

|
THINK How are rock composition and texture used to
About it classify, name, and interpret metamorphic rocks?

ACTIVITY 7.3 Hand Sample Analysis, Classification, and
Origin (p. 196 )

THINK What can metamorphic rocks tell us about Earth’s
About it history and the environments in which the rocks
formed?

L A B O R A T O R Y 7 ACTIVITY 7.4 Metamorphic Grades and Facies (p. 198 )

Metamorphic
Introduction
Rocks, Processes, The word metamorphic is derived from Greek and means
“of changed form.” Metamorphic rocks are rocks changed
and Resources from one form to another (metamorphosed) by intense
heat, intense pressure, or the action of watery hot fluids.
Think of metamorphism as it occurs in your home. Heat
C ONTRIBUTING A UTHORS can be used to metamorphose bread into toast, pressure can
Harold E. Andrews • Wellesley College be used to compact an aluminum can into a flatter and
James R. Besancon • Wellesley College more compact form, and the chemical action of watery
Margaret D. Thompson • Wellesley College hot fluids (boiling water, steam) can be used to change raw
vegetables into cooked forms. Inside Earth, all of these
metamorphic processes are more intense and capable of
changing a rock from one form to another. Thus meta-
Marble is metamorphosed limestone. It is being quarried here for
use in construction, table tops, decorative tiles, and sculptures. morphism can change a rock’s size, shape, texture, color,
(Fotografiche/Shutterstock) and/or mineralogy.
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