Advertisement Upgrade to remove ads


Sedimentary rocks

products of mechanical and chemical weathering

Sedimentary rocks are important for economic considerations because

they may contain
Petroleum and natural gas
Sources of Fe, Al, and Mn

Detrital sedimentary rocks

transported sediment as solid particles

Chemical sedimentary rocks

sediment that was once in solution

Organic sedimentary rocks


detrital rocks include

Clay minerals


Mud-sized particles in thin layers that are called laminae
Parallel alignment of grains
Barrier to flow of water
Low energy environments of deposition
Most common sedimentary rock--can be shales, mudstones, siltstones


Rock composed mainly of sand-sized particles
Forms in a variety of environments
Described by
Particle shape
Predominant mineral = quartz

Conglomerate consists largely of

rounded gravels

Breccia is composed mainly of large

angular particles

Inorganic processes

evaporation, chemical activity

Organic processes

-life processes of water-dwelling organisms


Most abundant chemical rock
Composed chiefly of the mineral calcite
Marine biochemical limestones form as coral reefs, coquina (broken shells), and chalk (microscopic organisms)
Inorganic limestones include travertine and oolitic limestone


Typically formed secondarily from limestone


Microcrystalline quartz
Varieties include flint, agate, and jasper


Evaporation triggers deposition of chemical precipitates


Different from other rocks because it is composed of organic material
1. Plant material
2. Peat
3. Lignite
4. Bituminous coal


Chemical, physical, and biological changes that take place after sediments are deposited and lithified.
Occurs within the upper few kilometers of Earth's crust

Two major textures are used in the classification of sedimentary rocks



Discrete fragments and particles
All detrital rocks have a clastic texture


Pattern of interlocking crystals
May resemble an igneous rock

Types of Sedimentary Environments


Marine Sedimentary Environments

Shallow ,Deep

Types of sedimentary structures

Graded beds
Ripple marks
Mud cracks

A sedimentary facies is the sedimentary rock's ________.

environment of deposition

Which of the following sedimentary rocks would you expect to have originally been deposited by fast-moving streams?


Oolitic limestone is most likely to form in what type of depositional environment?

shallow, clear marine waters with vigorous current activity

If shale is such a common rock in the sedimentary rock world, why isn't it as prominently exposed at the surface as sandstone?

Shale crumbles easily, causing increased mechanical weathering, whereas sandstone resists weathering more effectively.

Which of the following is a feasible explanation as to why quartz sandstone is an excellent use of "uniformitarianism"

Layers of sand-size quartz-rich sediment found today at the beach are virtually identical to layers in a 10-million-year-old sandstone, thus suggesting the location of the sandstone was the location of a beach 10 million years ago.

Many limestones are ________.


Which are sedimentary rocks?

Conglomerate and mudstone

How do you classify sedimentary rocks?

Texture and grain size

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording