SEDIMENTARY ROCKSThere are 2 ways sedimentary rocks are formed

1. Clastic are made from sediments glued together

2. Non-clastic: not glued together---include chemical & biochemical/organic

SEDIMENTARY ROCKS WILL CONTAIN FOSSILS.

SEDIMENTARY ROCKS FORM IN LAYERS CALLED STRATA

Oldest rocks are on the bottom….youngest on top

This is a good example of Stratification

1. CLASTIC Sedimentary Rocks are made from sediments that come from pre-existing rocks that have been weathered (breaking down into smaller pieces) and eroded (transported away) then glued together.

THE 2 CLASSES OF SEDIMENTARY ROCKS

The 2 types of weathering include physical (only size changes) and chemical (a new substance is formed).

Sediments range in size from tiny pieces of clay to sand, to pebbles, and to stuff as big as boulders

Clastic rocks form in a process called lithificaton which means compaction and cementation are occurring

Here’s How They Form:•Layers of sediment are deposited at the bottom of oceans and lakes

•As the layers build one on top of another, the pressure on the bottom layers COMPACTS the sediments together

•In the empty spaces between sediments, natural glues, like calcite, CEMENT the sediments together

Demo of

Sedimentator

Look at the processes that are occurring in

this animation

Clastic Process

Examples of clastic sedimentary rocks include

CONGLOMERATEBRECCIA

SANDSTONESHALE

2. Non-Clastic contain 2 types: chemical and biochemical

CHEMICAL Sedimentary Rocks are made from mineral crystals that formed from chemicals dissolved in water.

Here’s How They Form:•The water in the oceans, lakes, and underground is often full of dissolved minerals like halite and calcite.

•Water evaporates leaving the solids behind: rock salt is formed when salt is left after evaporation and limestone is formed when calcite is left behind

Limestone Cave

Chemical Sedimentary Rocks are also formed in caves where mineral-rich water drips from the ceiling, creating stalactites and stalagmites made out of limestone

Limestone

Examples of chemical sedimentary rocks include limestone and rock salt

BIOCHEMICAL OR ORGANIC Sedimentary Rocks are made from remains of once-living plants or animals (organic matter)

COQUINAMade from

shells

CHALKMade from dead

animals

Biochemical sedimentary rocks include: coquina, chalk, coal and limestone

•this is the sedimentary rock type with the most fossils

•will be found near areas of lots of biological activity

COAL

Made from dead plants

LIMESTONE with

fossils in it

AMAZING EARTH SCIENCE FACTS

1. Sedimentary rocks form 3 ways:1. _________ --compacted & cemented2. Chemical3. _______________

2. Sedimentary rocks are found in flat _________ or strata.

3. _______ are found in Sedimentary Rocks.

4. ____________is formed both chemically and organically.

Clastic-

layers

Fossils

Limestone

Biochemical

5. Clastic rocks are made of _____________, examples are conglomerates, sandstone and shale

6. Chemically formed sedimentary rocks form from _____________ ocean water, which leaves behind evaporates like ___________.

sediments

evaporatingrock salt