FINAL STUDY GUIDE

Make sure you listen to the answers

1. DEFINE ORGANIC AND INORGANIC

Organic: Made from living things

Inorganic: Not made from living things

2. WHAT ARE THE PROPERTIES OF MINERALS?

1. Naturally formed/occuring

2. Inorganic

3. Solid

4. Definite crystal structure

5. Definite chemical composition

3. HOW ARE IGNEOUS ROCKS FORMED? EXPLAIN THE DIFFERENCES BETWEEN INTRUSIVE AND EXTRUSIVE?

Heating and cooling Intrusive: inside, coarse grained slow cooling, large crystals, lava granite

Exstruve: outside, fine grained, fast cooling, small crystals, magma, obsidian

IGNEOUS ROCKSCoarse-Grained

Fine-Grained

Granite

Gabbro Basalt

Rhyolite

4. HOW AND WHERE ARE METAMORPHIC ROCKS FORMED? FOLIATED VS. NON-FOLIATED

Heat and Pressure. Found near plate boundaries

Foliated: banded

Nonfoliated: not banded

Meta=changeMorphic=form/

shape

5. HOW AND WHERE ARE SEDIMENTARY ROCKS FORMED.

Formed by Lithification and WEDCC.

1. Weathering 2. Erosion

3. Deposition4. Compaction

5. Cementation

a. Weathering – the breakdown of material at the Earth’s surface.g

i. The weathered material is

calledSEDIMENT.

ii. Sediment size varies – mud, sand,

gravel

b. Erosion – movement of sediment from on place to another by WIND, WATER, or ICE.

c. Deposition – dropping off the sediment in a new location.

Deposition of the Mississippi

Now it’s time to put them together!

d. Compaction (Squeezing)

e. Cementation (Gluing)

5 CONTINUED

1. Clastic: made from sedimentShale (clay)Conglomerate (gravel)Sandstone (sand2. Organic: made from living thingsChalkLimestone3. Chemical: Chemical reactionRock salt (water evaporating)

i. Sand becomes sandstone

ii. Clay and mud become shale

iii. Gravel becomes conglomerate.

Organic sedimentary rock is formed from previously living things.

i. Limestone – ocean life

ii. Coal – plant life on land

Chemical sedimentary rock is formed from a chemical reaction such as

water evaporating and leaving rocks behind.

6. EXPLAIN THE ROCK CYCLE

No start and no finish

Any rock can be made into another rock if it’s FORMED a certain way

PALEONTOLOGY

7. EXPLAIN EACH LAW

1. Superposition: older rocks on the bottom and younger on top

2. Horizontality: Layers are horizontal if not disturbed

3. Uniformitariansm: The same processes that are happening now have been happening for a long time

Younger rocks are on the top.

Older rocks are on the bottom.

Layers must be undisturbed

Superposition

Uniformitarianism – the idea that the same geologic processes shaping the Earth today have

been at work throughout Earth’s history

The principle of original horizontality means that layers of sediment are generally deposited in a

horizontal position.

8 PART 1 . ABSOLUTE

Older than 50,000 = Uranium lead Method

Younger than 50,000 = Carbon-14 Method

8 PART 1 . ABSOLUTE

Most precise Gives an actual agePuts a number to the age. This is why we use it!

Uses: Radioactive decayCarbon 14 or uranium lead Half-life

8 PART 2 . RELATIVE

Sequence Age COMPARED to other rocksOlder or younger NO NUMBERUses:Index fossilsLaw of superpositionLaw of original horizontality

9. WHAT DOES THE FOSSIL RECORD TELL US?

Geological changes such as dry areas that were once under water

Organisms have become more complex and how they have evolved

How the environment looked in the past How rock layers in different areas match

up How environment/animals have changed The age of certain layers of rocks

10. WHY ARE FOSSIL RECORDS INCOMPLETE?

Most organisms don’t become fossils

11. HOW OLD IS THE EARTH

About 4.6 billion years old

12. IN WHAT TYPE OF ROCK ARE MOST FOSSILS FOUND?

Sedimentary