Rocks, Minerals, Rock Rocks, Minerals, Rock CycleCycle

Fossils, Superposition, SoilFossils, Superposition, Soil

Rocks, Minerals, Rock Rocks, Minerals, Rock CycleCycle

Fossils, Superposition, SoilFossils, Superposition, Soil

Geology Test ReviewGeology Test Review

MineralsPg 64-79

• What are Minerals?• What characteristics must all

minerals have to be classified a mineral?

• What is Moh’s Scale? What do the numbers on the scale mean?

• Mineral- a naturally formed, inorganic solid that has a definite crystalline structure

• A mineral must be • 1)Nonliving • 2) A Solid • 3) Have a Crystalline Structure• 4) Formed in nature

• Moh’s Hardness Scale is used to determine the hardness of a mineral.

• Talc has a rating of 1 and diamond has a rating of 10

• The greater a mineral’s resistance to being scratched is, the higher the mineral’s rating is.

Rocks• What are the three classification of

rocks?• How are each rock types formed?• What are some example names of

each rock type?

Rocks• The rock types are Igneous, Metamorphic, and

Sedimentary

• IGNEOUS ROCKS• Igneous rocks formed when hot, liquid rock, or magma,

cools and solidifies • Igneous comes from a Latin word that means FIRE!• Examples of Igneous rocks are Obsidian, Granite, Pumice, Basalt

• Sedimentary rocks form when mud, silt, gravel, or sand is subjected to compaction and cementation.

• They are also formed from eroded materials that settle in layers

• Examples include Sandstone, Conglomerate, Limestone

Metamorphic Rock• Rocks in which the structure, texture or the composition of

the rock have changed by heat pressure or a combination of both

• “Meta” means changed “morphos” means shape

• Examples include marble, gneiss, slate

Rock Cycle• What are the stages of the rock cycle? The Rock Cycle is a

group of changes. Igneous rock can change into sedimentary rock or into metamorphic rock.

Weathering

• What is mechanical and chemical weathering?

• What are examples of mechanical and chemical weathering?

Weathering• Weathering is the breaking down of rocks on Earth’s surface by wind

water and other processes.• Mechanical Weathering• Mechanical Weathering is the process of breaking down rock into

smaller pieces. The make-up of the rock is not altered only the size. There are 5 agents of mechanical weathering :

• 1) Ice• 2) Wind• 3) Water• 4) Gravity• 5) Plants• 6) Animals

• Pages 278-279

Mechanical Weathering

Chemical Weathering• The process by which rocks break down as a result of

chemical reactions.

• Chemical weathering alters the mineral composition, or the chemical makeup, of the rocks.

• Common agents of chemical weathering are:• 1)Water• 2)Weak Acids (Acid Rain, Acid in groundwater, Acid in

living things) • 3) Air• Pages 281-283

Chemical Weathering

Erosion & Deposition• What is erosion and deposition?

Erosion• Erosion is the process by which

wind, water, ice, or gravity TRANSPORTS soil and sediment from one location to another.

Deposition• The process in which sediment

moved by erosion is dropped and comes to rest, it’s laid down

Superposition• What is the principle of

superposition?

• Superposition – a principle that states that younger rocks lie above older rocks if the layers have not been disturbed.

Fossils• In which type of rock would you

find fossils?

• What is the difference between an index and trace fossil?

• You would find fossils in Sedimentary rock.

• You can find some fossils preserved in the layers of sedimentary rock

Fossils• What is the difference between an

index and trace fossil?

• An index fossils is a fossil that is found in the rock layers of only one geologic age and that is used to establish the age of rock layers

• A trace fossil is a fossilized mark that is formed in the soft sediment by the movement of an animal (ex: dinosaur tracks)

Soil• What is soil?• What are the different layers of

soil?• How do humans contribute to soil

erosion?

• Soil is a loose mixture of rock fragment, organic material, water, and air that can support the growth of vegetation

Layers of Soil• Topsoil- contains Humus and contains most of the

nutrients. This is where the shallow roots of plants pick up nutrients and water

• Subsoil- middle layer light-colored does not contain many nutrients. This is where you find clay and minerals washed down by water seeping through the topsoil

• Parent material• Weathered bedrock• Bedrock – is the solid layer of rock below the soil and

loose rock

• Humans contribute to soil erosion by farming, cutting down trees to clear land for building

• Roots form plants and trees are like anchors to the soil. Roots keep topsoil from being eroded; therefore plants and trees protect the soil.