Download File

GEOLOGY
METAMORPHIC ROCKS LECTURE
Name____________
Standards
 Classify matter in a variety of ways
 Describe the composition and structure of Earth’s materials, including:
 the major rock types (i.e., sedimentary, igneous, metamorphic) and their
formation
I.
Properties of Metamorphic Rocks
A. ____________________ means ______________ in ___________.
B. Metamorphic rocks are formed when existing rocks undergo changes.
1. Sedimentary & igneous rocks can change into metamorphic rocks, and
metamorphic rocks can change into different metamorphic rocks.
D. During the process of metamorphism, rocks and minerals change in
response to changes in ________________, ______________ or
other _______________________ changes.
E. The _______________, ______________ and/or ______________
composition of the rocks may _________ during metamorphism.
F. Most metamorphic reactions (changes) occur while the rocks are in a
_________ state (if the rock becomes liquid, it is an igneous rock).
II.
______________ Changes
A. The average _________ of ____________ in the rock usually
_______________.
B. The __________ and _____________ of crystals in the rock change
Ex: _________________ changes to ___________: still made of the
mineral calcite, but it is now _________ and its texture is
___________ with irregularly shaped, interlocking grains.
III. _____________ Changes
A. In general, if the original (_________) rock contains ______ mineral,
metamorphism produces a rock of the _________ mineral.
Ex: limestone changes to marble, both are made of calcite
B. If ____________ minerals are present in the parent rock, the new
metamorphic rock may have ________________ minerals.
Ex: shale contains clay minerals, quartz & feldspar. During
metamorphism, these minerals change to chlorite.
III. __________________ of Metamorphic Rocks
A. Metamorphic rocks are formed by high temperature and/or pressure
1. ________________ induced changes
a. _____________ temperatures cause metamorphism:
b. ____________ temperatures cause _______ changes and
produce _______ of a change.
c. _____________ temperatures cause ____________
changes and produce a _____________ change
2. _____________ induced changes
a. Chemical ________________ are sensitive to pressure
(measured in kilobars).
b. Greater amounts of pressure will produce greater changes.
c. ________________ – change in the shape of rocks or
minerals in response to mechanical __________
d. ______________ activity causes _____________ that
creates foliation in metamorphic rocks.
e. ______________ is a set of flat or wavy __________ in a
metamorphic rock
f. Types of foliation:
i.
________ cleavage – rock ______ into thin sheets
ii.
Schistosity – wavy, parallel arrangements of
minerals
iii. ____________ – alternating __________, or
bands, of light and dark minerals
B. Types of Metamorphism
1. _______________ Metamorphism
a. Caused by __________ or strong ___________ forces
that impose high temperatures and ______________ on
the rocks over a large area.
b. Most metamorphic rocks are of this type.
c. These rocks are ______________.
d. Types of Regional Metamorphic Rocks:
Rock Names
Parent Rock
• _________…………………shale
• Phyllite………………………..._______
• _________……………….shale
• Gneiss………………………….shale, granite or conglomerate
2. ______________ Metamorphism
a. Caused by ________ and pressure produced by a nearby
igneous _____________.
b. Does not cover large areas like in regional metamorphism.
c. Heat plays a greater role than pressure.
d. These rocks are called _______________ and are nonfoliated.
e. Types of contact metamorphic rocks:
Rock Names
Parent Rock
• Metaconglomerate……......_____________
• _____________……………sandstone
• Marble………………………………_____________
3. __________________
a. Super-heated ___________ enters pore spaces or
_______________ in rocks and creates metamorphic
changes.
b. Many deposits of valuable metal ______, such as
_________, zinc and ________, are formed in this way.