Name: ________________________
Due Date: _____________________
Per: ________
40 minutes
Metamorphic Rock Identification
Objective: By the end of this activity you should be able to:
1.
2.
3.
Identify various metamorphic rock specimens
Use a flow chart key
Decipher a rock scheme table
Background: Metamorphic rocks are formed when existing rocks are changed
by intense heat, pressure and/or chemical activity within the Earth’s crust.
These new rocks may be denser, harder or more crystalline than the rocks from
which they were formed. They may contain new minerals that were not in the
original rock which may be squeezed flat and arranged in parallel bands. These
bands are called foliations. Rocks that do not have banding are called nonfoliated metamorphic rocks.
Regional metamorphism occurs over a large geographic area and is usually
associated with extensive mountain building or great depths (and therefore
intense pressure) within the crust. Contact metamorphism occurs along the
interface between hot, molten rock and the rock it touches and is associated
with volcanic activity.
Materials: ESRT, hydrochloric acid, glass slide, hand lens, samples of
metamorphic rock (numbered 1-8)
Procedures:
1.
Obtain an unknown specimen of metamorphic rock and match it with
the sample number in the Metamorphic Rock Identification Table.
2.
Observe and record the grain size.
3.
Record if the rock is foliated or nonfoliated
4.
Using the information from the table, the Metamorphic rock key flow
chart, and the ESRT, identify each sample.
5.
After identifying the sample, use the ESRT to identify the type of
metamorphism (regional or contact) and the probable original rock for the
sample.
VVS Earth Science
Minerals and Rocks
Metamorphic Rock Identification
Page 1 of 4
Metamorphic Rock Identification Table
Rock No.
Grain Size
Foliated or
Nonfoliated
Type of
Metamorphism
(Regional or Contact)
Rock Name
Origin Rock
1
2
3
4
5
6
7
8
VVS Earth Science
Minerals and Rocks
Metamorphic Rock Identification
Page 2 of 4
Questions:
1.
What characteristics do all metamorphic rocks have in common?
_______________________________________________________________
_______________________________________________________________
2.
Why are fossils very seldom found in metamorphic rocks?
_______________________________________________________________
_______________________________________________________________
3.
Why are the minerals in many metamorphic rocks arranged in foliations?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
4.
How can a sample of marble be distinguished from a similarly appearing
sample of quartzite?
______________________________________________________________
_______________________________________________________________
_______________________________________________________________
VVS Earth Science
Minerals and Rocks
Metamorphic Rock Identification
Page 3 of 4
VVS Earth Science
Minerals and Rocks
Metamorphic Rock Identification
Page 4 of 4