GEOLOGY SEDIMENTARY 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. _______________________ Rocks
A. Cover ____% of Earth’s surface
B.
Make up only 5% of the crust by volume
C.
Form by ________________ and lithification of sediments
1.
________________________ = the process of turning sediments into sedimentary rock by compaction &/or cementation a.
____________________ = grains squeezed together by overlying sediments b.
____________________ = minerals precipitate around sediments and bind them together
D. 3 Types of Sedimentary Rocks
1.
Clastic
2.
Chemical
3.
Organic
II. __________________ Sedimentary Rocks
A. Are formed from fragments of other rocks by the following process:
1.
_______________________ breaks rocks into fragments
•
Physical weathering occurs by: a.
Water b.
_________ (also called eolian) c.
Gravity, or d.
______________

Chemical weathering occurs by: a. Chemical reactions
2.
The rock fragments are ______________ and _______________________ to new locations by water or wind
3.
The rock fragments are deposited – called __________________________
4.
The rock fragments are buried and turned into rock (lithification). a.
_____________________ agents are sometimes present and help turn the sediments into rock. b.
Types of cementing agents are ________, iron and _______________
B. Deposition of Sediments
1.
As sediments are transported from their source, the __________________ fragments get deposited _____________ (i.e., closest to the source).
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2.
This happens because the current that is carrying the sediments slows, and therefore can no longer carry the larger particles.
3.
This means that large sediments get deposited in _____________ energy environments and small sediments get deposited in low _______________ environments.
4.
Examples: _______________ are deposited in _________________ streams, sand is deposited on beaches, and ________ is deposited in the ___________
C. Naming Clastic Sedimentary Rocks
•
Clastic sedimentary rocks are _______________ according to the _________ of the _____________________ that make them.
Fragment size
Coarse mm
64 – 2
Fragments Rock names
___________ conglomerates gravel ______________
Medium 2 – 1/16 sand ______________
Fine to Very fine 1/16 – 1/256 ________ clay siltstone
____________
D. Grain ________________
1. The size of grains in a sedimentary rock will be either well-sorted (all near the
same size) or poorly-sorted (lots of different sizes). a. __________-sorted sediments have been transported farther than
____________-sorted sediments. b. Wind-transported sediments are more well-sorted than water transported
sediment.
E. Grain ________________
1.
Grains in a sedimentary rock will be either _________________ or
_______________, depending on how far they have been transported.
2.
Grains that have been transported further get abraded longer and are thus more rounded.
III. _________________ Sedimentary Rocks
A. Chemical sedimentary rocks are formed by:
1.
___________________ out of a solution (a solid comes out of solution)
2.
___________________
3.
Chemical action
B. Names of Chemical Sedimentary Rocks
1.
___________________ – made of ______________ &/or tiny sea creatures
2.
Rock salt (halite) – formed by evaporation
3.
Rock _____________ – formed by ___________________
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4.
Silicates – ____________________ (or cryptocrystalline) quartz
exs: ___________, chalcedony
5. ____________________ – _______________ (clumps) of silica in limestone
with ____________ or _____________ crystals in center (____________)
6. _________________________ – ___________________ of plant and animal
remains by another ______________ = fossil a. Ex: ______________ wood: wood is replaced by microcrystalline ______
III. _________________ Sedimentary Rocks
A.
Organic sedimentary rocks are formed from __________ and ______________.
B.
Organic material dies, gets buried and turns into sedimentary rock.
C.
Names of Organic Sedimentary Rocks
1.
Some limestone
2.
________________ – made of ___________ and limestone
3. Coal – made of plants, _________
4. _______________ – made of microorganisms
IV. Sedimentary Structures
A.
Sedimentary _____________________ – features that are formed in sedimentary rocks when the sediments are deposited (i.e., before the sediments are turned into rock).
B.
They include:
1. bedding
2. cross-bedding
3. graded bedding
4. ripples
5. bioturbation structures
C. _________________
1.
Also called ______________________.
2.
Occurs when layers of different grain sizes or compositions are deposited on top of one another. Can be from millimeters to meters thick.
D. ____________-Bedding
1.
Sets of bedded material inclined at _______________ to each other.
2.
Occurs when sediments are deposited on steeper, downcurrent slopes of sand dunes or sandbars.
E. _______________ Bedding
1.
Progression of a bedding layer from _______________-grained at the bottom to
___________- grained at the top.
2.
Indicates a weakening of the current carrying the sediment.
F. _______________
1.
Low narrow ______________.
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2.
Symmetrical or asymmetrical. a.
__________________ Ripples i. Formed by back and forth motion of ____________. b. ___________________ Ripples i. Formed by _______________ moving in one direction.
G. ______________________ Structures
1. Tubes and other structures left by _________________ organisms
IV. Sedimentary Rocks are _____________________ Important
A.
______________ is a major ______________ resource
B.
Limestone is used as building material, stone and an ingredient in cement
C.
__________ and native elements such as copper, lead, zinc, iron, gold & silver are all concentrated in sedimentary rock
D.
______________ are found in sedimentary rocks
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L. Brown
Updated December 2013
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