Rocks, Minerals, and Soil

http://techalive.mtu.edu/meec/module10/Decomposition.htm

Minerals

Minerals are ‘ingredients’ of rocks

There are over 3,000 known minerals in the world

*

Properties

We use many different kinds of words to describe and sort rocks including:

ColorLuster (dull or shiny)

Texture Hardness

Transparency

Igneous Rocks

Igneous means made from fire or heat

There are two major types of igneous rock; extrusive and intrusive

Extrusive is created when magma comes to the earth’s surface and becomes lava. When lava cools, it becomes rock, such as obsidian

Intrusive like granite is formed inside the earth’s crust when magma hardens

Obsidian Granite

Basalt*Google images

Sedimentary

Large rocks break down into smaller rocks and sand (sediment)

Over time, this sediment settles to the bottom of bodies of water and creates sedimentary rock due to time and pressure

Fossils are found in sedimentary rocks

It can often be identified by its layered or conglomerate design or sandy texture

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

*Google images

Metamorphic

Metamorphic means to change form

They are created when sedimentary and igneous rocks are heated, squeezed and folded during movement of the earth’s crust

Marble is a metamorphic rock Banding and layering can

occur; they are the least common of the three kinds of rocks

Gneiss Marble*Google images

Soil

Soil is made of:

-air and water

-living organisms

-organic matter ( leaves, grass, twigs, roots)

-rocks and minerals

-decomposed plants and animals

Soil is different from place to place because of weather and climate, parent material, and organisms.

How is soil created?

Soil is created over time by:

-rocks and minerals breaking down; weathering and erosion: wind, water, chemical, ice, plant

-decomposition

Three Types of Soil

Clay

Silt

Sand

Clay

There are three types of soil, and they are classified by their texture and particle size.

In clay, particles are small and they clump together.

When wet, clay soil feels like modeling clay.

Clay doesn’t drain water very well because it is packed together tightly.

Silt

Silt has smaller particles than sand, but larger particles than clay.

Silt’s texture is similar to that of flour, powdery.

It is the darkest and loosest of the three soils.

Sand

Sand has the largest particles (like sugar).

Its texture is gritty.

It has the best ability to drain water out of all three types of soil.

- www.rain.org

Soil Profile

O: Organic Matter A: Topsoil (loam) E: Subsoil- mostly silt

and sand B: Subsoil- mostly clay C: Parent Material R: Bedrock

What if there was no soil?

Without soil we wouldn’t have blue jeans! Jeans are made of cotton denim stitched together with cotton thread. Their blue color comes from indigo dye.

Cotton and indigo come from plants that need soil to grow. If we did not have soil healthy soil the plants

necessary to make jeans would not exist!