Chapter 7: A Trip Through Geologic TimeLearning Target Vocabulary Word Definition Facts or Examples Symbol/PictureLesson 1

I can explain how fossils form . . . fossils

______________remains or _________ of living things. Most fossils form when living

things die and are buried in__________.

The sediment slowly hardens into ______and preserves the

shapes of the organisms. Most fossils form from animals that lived in or

near___________, lakes or shallow ________.

I can identify the different kinds of

fossils . . . molds

A ___________ area in sediment in the __________of an

organism.

cast A solid ________ of the shape of an organism

Often formed when water deposits ___________ and

sediment into a __________.

petrified fossils

A fossil in which ___________ replace all of an organism or a

part.

Examples include dinosaur bones and tree trunks. Water

evaporates.

carbon films

An extremely thin ___________of carbon on rock that occurs

when sediment buries & organism and some

________ escape.

This can preserve delicate parts of ____________and

____________.

trace fossils A fossil that provides ____________ of the

___________of ancient organisms

Ex. footprints, trails, burrows, nests

preserved remains

An entire organism can be preserved in tar or ____________ (tree resin) or from

freezing.

La Brea tar pit in California

I can describe what fossils tell about organisms

and environments of the past . . .

paleontologists

Scientists who study

_________________

The fossil record provides evidence about the

____________of life and past environments on Earth.

Shows how organisms have ____________over time or

changes in climate

evolution The change in living things over time.

extinctAn organism that no longer _________ and will never again live

on Earth.

Lesson 2I can describe how

geologists determine the relative age of

rocks…

relative age The age ___________ to the ages of other

rocks.

absolute ageThe number of

_________ that have passed since the rock

___________I can sequence rock layers by

using the laws of superposition ,

cross cutting and

Law of superposition

In undisturbed _______________

sedimentary rock layers, the oldest

layer is at the

Each higher layer is ____________ than the layers

below it.

index fossils . . . ___________

extrusion Lava that hardens on the _________ and forms ___________

rock

Extrusion is always _________ than the rocks below it.Part of the law of cross

cutting (You can't cut a pb & jelly sandwich until you make

one)

intrusionWhen ________ pushes

into bodies of rock __________the surface

and cools and hardens into a mass

of igneous rock

An intrusion is always _________________ than the

rock layers around and beneath it.

Also the law of cross cutting!

faultA __________ in Earth's

crust

A fault is always __________than the rock it

cuts through. Geologists find the _________ age of the

youngest layer cut by the fault.

index fossilsA fossil that is widely

____________ and represents an

organism that existed for a geologically ________ period of

time.

They can be used to __________ rock layers from

different ______________.

I can explain how unconformities and folding can

alter the order or rock layer…

unconformity The surface where new rock layers

________ a much older rock surface beneath

them.

A ______in the ____________ record. Is shows where rock layers have been _______ due

to ___________

foldingSometimes, forces

inside Earth fold rock layers so that the _____________ rock layer may be on

the_______________.Lesson 3

I can explain what happens during

radioactive decay …

radioactive decay

Atoms of one __________ break down

to form atoms of another element

Radioactive elements release __________ and __________ in the process of radioactive

decay

half-life The time it takes for

half of the ___________

atoms to ___________

I can describe what can be learned from radioactive

dating…

Scientists determine the amount of a

radioactive element in a rock.

Then they compare that amount with the amount of the stable element into which the radioactive element decays.

They use this information and the half

life of the element to calculate the age of the

rock.

Potassium-argon dating

Potassium -40 decays to argon-40, half life

is _______ billion years

Good for dating very old

_____________

Carbon-14 dating

Carbon 14 decays to Nitrogen 14, half life is _____________ years

Not good to date fossils older than ___________ years or

_____________ because they don’t contain much carbon

Lesson 4

I can explain how and why the

geologic time scale is used to

show Earth’s history…

geologic time scale

A record of the geologic _________

and _____________ of life forms as shown in the __________ record.

Because the time span of Earth’s past is so __________, geologists use the geological

time scale to show Earth’s____________.

See picture on next page

Precambrian Time

______ % of Earth’s history, ended

________million years ago

Very few fossils

eras Long units of time

1. ________________ (fish, insects, land plants)

2. ________________ (reptiles, dinosaurs, flowering plants)

3. _______________ (mammals, grasses & humans)

periods______ are divided into smaller units of time

called periods.

Paleozoic has Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian

Mesozoic has Triassic, Jurassic, Cretaceous

Cenozoic has Paleogene, Neogene, Quarternary

Lesson 5

I can explain how Earth developed

during the Precambrian

time . . .

Scientists think that Earth began as a ball of_________ , rock and ____________ in space.

____________pulled this mass together. The __________ from these collisions raised the ____________________ so high that the Earth __________.

____________ materials sank toward the center forming the __________ core. The Earth is _____

billion years old.

comet

A ball of dust, gas, and ice that orbits the

_____. Volcanic eruptions &

__________with comets add CO2, water

vapor, N2, and other gases to our atmosphere.

Less than _________ million years after the Earth formed, the rock at the surface formed______________________.

Scientists have found _________ of single

celled organisms from _____ billion years ago.

Lesson 6

I can describe the major events of

the Paleozoic Era . . .

________________–

invertebrates in ocean

____________– fish, Silurian – plants

and insects, _____________ – Age

of Fishes, amphibians

___________________– reptiles, swamp plants turned into __________ millions of years later

__________– Pangea formed, Mass

extinction _____ ocean species, ____ land species died out.

invertebrates Animals without ______________

Ex. Jellyfish, _________, sponges, Brachiopods and ___________ all lived in Cambrian ocean.

vertebrates Animals with a ___________

__________ fish evolved in the ________________ time period

first land plants

Ferns____________ period – plants became abundant in ________ areas. Devonion Period – plants in __________ areas

early fish Fish with _______, bony skeletons,

_________ and sharks

_____________ Period known as the Age of Fishes

amphibian An animal that lives part of its life on

________ and part of its life in the

_________.

The first amphibians evolved from the ______________.

reptiles Animals that have ________skin, lay eggs

that have tough, ___________ shells

Small reptiles evolved during the ___________________ period.

I can describe the major events of

the Paleozoic Era . . .

Mesozoic Era known as Age

of

____________

___________– First dinosaurs

appeared, some small mammals

____________ – land dinosaurs, first birds

________________ – reptiles, birds,

flowering plants. ___ million years ago – mass extinction.

I can describe the major events of

the Cenozoic Era . . .

Cenozoic Era –________________

evolved to live in land, water, air

__________ & Neogene – whales and dolphins, first

grasses, large mammals and birds

__________________ – glaciers, Ice Ages, Modern ___________ 190,000 years ago.

Learning Targets Chapter 7

Lesson 1 I can explain how fossils form . . .

Most fossils form when ____________________ hardens into ___________, preserving the _________________ of organisms.

I can identify the different kinds of fossils . . .

Fossils include _____________, ________________, ________________ fossils, ____________ films, ______________ fossils, and ________________ remains.

Lesson 2 I can describe how geologists determine the relative age of rocks…

In ____________________ sedimentary rock layers, the _____________ layer is generally at the bottom. Each layer is ________________ than the layers below it.

I can explain how unconformities and folding can alter the order or rock layer…

____________in the geologic record and __________ can change the ____________in which rock layers appear.

Lesson 3 I can explain what happens during radioactive decay …

During radioactive _________, the atoms of one __________ break down to form atoms of another element.

I can describe what can be learned from radioactive dating…

In radioactive dating, scientists compare the amount of a _______________ element in a rock with the amount of the ________________ element into which the radioactive element _______________.

Lesson 4 I can explain how and why the geologic time scale is used to show Earth’s history . . .

Because the time _________ of Earth’s _________ is so great, geologists use the geologic time scale to show Earth’s history. After Precambrian time, history is broken down into 3 __________________ and then many smaller ___________.

Lesson 5 I can explain how Earth developed during the Precambrian time . . .

Scientists think that Earth began as a ball of ______, rock, and ________ in space. ____________ pulled this mass together.

Lesson 6 I can describe the major events of the Paleozoic Era . . .

During the Paleozoic Era, a great number of different organisms _______________.

I can describe the major events of the Mesozoic Era . . .

_____________ spread widely during the Mesozoic Era.

I can describe the major events of the Cenozoic Era . . .

During the Cenozoic Era, ________________ evolved to live in many different ________________________.