Download Sedimentary Rock Guided notes key

NAME KEY DATE_____________ PERIOD________
SEDIMENTARY ROCK NOTES
(pgs. 102-105)
I. ORIGINS OF SEDIMENTARY ROCK (pg. 102)
1. List the agents that cause rock to physically weather into fragments.
a. wind
b. water
c. ice
c. sunlight
d. gravity
2. Define sediment. Tiny rock and mineral fragments.
3. Describe how sediment becomes sedimentary rock.
Old rock is physically weathered (broken down) and eroded away. When the sediment is deposited it
creates a layer of tiny rock pieces. As new layers are formed the rock pieces get compacted and
cemented together.
4. Where does sedimentary rock form? At or near the Earth’s surface.
5. Define strata. A single horizontal layer of rock
II. COMPOSITION OF SEDIMENTARY ROCK (pgs. 103-104)
6. How is sedimentary rock classified? By how it forms (3 types: Clastic, chemical, organic).
7. Compare “Clastic, Chemical & Organic Sedimentary Rock” using the chart below.
CLASTIC
a. Forms when…. Rock or
mineral fragments, called
clasts are cemented together.
CHEMICAL
a. Forms when…. Minerals
crystallize out of a solution such as
seawater.
ORGANIC
a. Forms from…the remains
of once-living plants and
animals.
b. Made of…..fragments of
rocks cemented together by
minerals like calcite or quartz.
b. Describe how halite forms.
When sodium ions and chlorine
ions in shallow bodies of water
become so concentrated that halite
crystallizes from the solution.
b. Describe how limestone
forms. Fossils from coral
reefs and other sea animals
collect on the ocean floor and
become cemented together.
c. Classified according
to….the size of the fragments
from which the rock is made.
d. Types of
textures…..Coarse grained,
medium grained, fine grained
e. Examples….conglomerate,
sandstone, siltstone, shale
c. Describe how coal forms.
Coal forms underground
when partially decomposed
plant material is buried under
sediment and is changed into
coal by increasing heat and
pressure over millions of
years.
III. SEDIMENTARY ROCK STRUCTURES (pg. 105)
8. Define “stratification”. The process in which sedimentary rocks are arranged in layers.
9. Strata differ from one another depending on the kind, size, and color of their sediment.
10. Sedimentary rocks sometimes record the motion of wind and water waves on lakes, oceans,
rivers, and sand dunes in features called ripple marks.
11. Describe how mud cracks form. What do mud cracks indicate? Mud cracks form when fine
grained sediments at the bottom of a shallow body of water are exposed to the air and dry out. Mud
cracks indicate the location of an ancient lake, stream, or ocean shoreline.
CRITICAL THINKING
12. Rocks are classified based on texture and composition. Which of these two properties would be
more important for classifying clastic sedimentary rocks?
Clastic rocks are determined by the size of their sediment, so texture is more important to classifying
clastic sedimentary rocks.