SEDIMENTARY ROCKS

Amy Arico


Welcome to a "Sedimentary Rocks" lesson.  I am currently teaching the third grade standards at Chukker Creek Elementary, and I needed information on Sedimentary Rocks.  I explored different resources, combined them, and hopefully this will you help to further your knowledge about this subject matter as much as it helped me while creating it.

 

Question:

How are Sedimentary Rocks formed?

Over thousands and thousands of years, pieces of the earth's crust have been broken and worn down, or eroded, into small bits or particles.  This has taken place due to the impact of the wind and water constantly swaying and moving against the crust.  Once it was broken down into these pieces, those pieces were washed downstream where they ended up settling at the bottom of lakes, rivers, oceans, or streams.  Over years and years of setting on top of other worn and washed particles, thicker layers began to form.  These layers became heavier, weighing down on the bottom layers, until finally a type of rock formed near the bottom.  This formation resulted in Sedimentary rocks.  The crust continues to erode, and everything works like a cycle, which is why Sedimentary rocks are still forming as we speak.
 

Question:

What are some characteristics of rocks that were formed through the sedimentary process?

-SANDSTONE-

Sandstone layers typically have a medium-gray color.  On newly broken surfaces
it can have from white to tan or reddish brown.  This stone can produce sand bars along
creek channels and sandy soils of different bottomlands.


-LIMESTONE-

Limestoneusually is found as a white to yellowish or grey.  Some can have specks of black within it
if the rock has a great amount of hydrocarbons.  This type of rock is found throughout the world
It is often used as a type of cement, for building some buildings, or even for blackboard chalk.


-SHALE-

Shale is a type of sedimentary rock that is a shade of grey and splits into thin plates quite easily. This type
of rock is also found worldwide.  Its use is a source of fossils.  Clay, quartz and mica can be found
within this sedimentary rock.


-CONGLOMERATE-


 

This type of sedimentary rock has very unique features.  The different boulders, pebbles,
or shingle can often be seen very distinctly.  It sometimes will look like rocky concrete.  Its color
depends on the type of rocks that joined together.  This kind of rock is often used as types of ornaments
when the rock is cut and polished.


-COAL-

Coal is a dark, hard rock.  When burned, it creates a bright-yellow flame.  It contains a metallic
look.  This rock is mostly found in the US, southern Russia, Ukraine, UK, China, and Africa.  It is
mainly used for domestic and industrial fuel.


-BRECCIA-

This rock  is similar to the comglomerate because it is made up of different rock fragments, mostly fine sand or silt. Again,
the color depends on the rocks found within it.  It is found throughout the world, as well, and used
for ornamental objects when the rock is tightly compacted.



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The views expressed on this page are not necessarily those of the University of South Carolina
http://rpsec.usca.sc.edu/Classwork/731sp2001/Lesson/Arico/ sedimentary2.html  (January, 2001)