Rocks and Soil

Rocks

• ROCKS• The rocks you see around you - the mountains,

canyons & riverbeds, are all made of minerals. A rock is made up of 2 or more minerals. Think of a chocolate chip cookie as a rock. The cookie is made of flour, butter, sugar & chocolate. The cookie is like a rock and the flour, butter, sugar & chocolate are like minerals. You need minerals to make rocks, but you don't need rocks to make minerals. All rocks are made of minerals.

Rocks• Properties of Rocks (how we

categorize them)• Texture • Layering• Color

Texture•How smooth or rough they

are

• http://www.classzone.com/books/earth_science/terc/content/investigations/es0603/es0603page02.cfm

Layering

• http://www.classzone.com/books/earth_science/terc/content/investigations/es0610/es0610page04.cfm

3 types of rocks• Igneous Rocks

• Metamorphic Rocks

• Sedimentary Rocks

Igneous Rocks

•Igneous rocks form directly from the cooling of magma.

• http://www.fi.edu/fellows/fellow1/oct98/create/igneous.htm

Metamorphic Rocks

• The metamorphic rock gets the name from "meta" (change) and "morph" (form).

• The rock is moved into an environment in which the minerals which make up the rock become unstable. In most cases, this involves burial which leads to a rise in temperature and pressure.

• http://www.fi.edu/fellows/fellow1/oct98/create/metamorph.htm

Sedimentary Rocks

• In most places on the surface, the igneous rocks which make up the majority of the crust are covered by a thin layer of loose sediment, and the rock which is made as layers of this debris get compacted and cemented together.

• http://www.fi.edu/fellows/fellow1/oct98/create/sediment.htm

Rock Cycle• http://www.classzone.com/books/earth_sci

ence/terc/content/investigations/es0602/es0602page02.cfm

Smaller rocks come from the breakdown

of larger rocks through the action

of plants and weathering

Soil

Composition

• Soil is made of:–Small rocks–Decomposed pieces of plants and animals•Dead plants•Dead animals

–Products of plants and animals•Animal waste

Properties of Soil• Color

– Is it dark or light?• Capacity to retain water

–Does it hold a lot of water?• Capacity to grow plants

–Does the soil have nutrients like nitrogen to help plants grow well?

• Texture–How does it feel?

Kind of soil

How it feels Hold shape when wet

Sandy Feels gritty Won’t stick together when wet

Silty Feels powdery

Will stick together when wet but will not hold together after it dries

Clay Feels sticky Stays together when wet

Which is clay? Which is sand?

• Soil is also found in layers like rocks, with topsoil on top.

• Each layer is

called a horizon

• http://www.classzone.com/books/earth_science/terc/content/investigations/es1206/es1206page02.cfm?chapter_no=investigation