Sedimentary Rocks 2

Clastic, Chemical, and Organic

Natural Resources (coal and oil)

Vocabulary

Topography: The landscape of a place

Precipitation: The process of forming rock from a solution through evaporation

Clastic Sedimentary Rock

Clastic rock is formed through when fragments of other rocks are deposited, compacted and cemented together.

Clastic rock can take many different forms depending on the size of the fragments (clasts)

Examples of clastic rocks include: Shale, Sandstone, Mudstone, Conglomerate, and

Coal

The fragments (clasts) can be very small or quite bigSandstone Conglomerate

Let’s see this in action…

http://www.classzone.com/books/earth_science/terc/content/visualizations/es0605/es0605page01.cfm?chapter_no=visualization

Chemical Sedimentary Rock

Chemical sedimentary rock forms through the process of PRECIPITATION. A solution such as sea water evaporates and leaves behind the minerals to create a new rock.

Limestone is made from a solution of Calcite that comes from sea shells

Halite (rock salt) is made when highly concentrated salt water

Often, these types of rocks are formed in arid climates where evaporation is most intense

Some examples…

Halite Limestone

Organic Sedimentary Rock

Organic sedimentary rock is made from organic matter

Because organic matter can burn, this kind of rock is often used for energy.

Coal is made from dead vegetation in swamps that is compacted over time

Oil is made from dead microorganisms (like algae) that fall to the bottom of the ocean and are compacted over millions of years.

That is why they are called FOSSIL FUELS!!

Let’s see how coal is made…

http://www.sceyencestudios.com/movies/coalformation.swf

Coal Mining

Where is oil found Oil is found in sedimentary rocks that are POROUS

and can soak up the oil.

When geologists are looking for oil, they look for sedimentary rocks like shale that can hold oil.