Earth’s Age + Evidence

WARM UP• Update your Table of Contents for today’s

activities• Get your data folder off the front desk• Complete Types of Rock Review section

at the top of your note guide

Date Session#

Activity Page#

9/13 7 Earth’s Age & Evidence Note guide 14

Law of Superposition Practice 15

Review: Types of Rock

Which one?

- Created from the deposition of loose material accumulating into layers and being pressed together over time

Review: Types of Rock

Which one?

-The result of the transformation of other rocks into a new form

Review: Types of Rock

Which one?

- Created when molten rock (magma) cools and hardens

Notes Tips and Tricks

• Anything in yellow you MUST write on your note guide

• Pictures and diagrams are great things to also draw to help you remember vocab and ideas!

• Underlined or bold words that are underlined or bold in PowerPoint BECAUSE THEY ARE IMPORTANT!

How old is the Earth?

Earth is around 4.6 BILLION years old.

BIG QUESTION:

HOW DO WE KNOW HOW OLD THE

EARTH IS?

BIG ANSWER:

Everything coming up provides an

answer to the BIG QUESTION!

Law of Superposition

• Law of Superposition– •Under normal conditions, the layers of sediment get older the deeper you get

Examples of Law of Superposition

• Just like a layered cake…you put the bottom layer down first,

so it is the “oldest” and

you fill in each layer on

top of it! What examples

can you come up with?

Draw your own picture

illustrate the concept!

We Have a Problem…

• There are several things can mess up the Law of Superposition called unconformities

Types of unconformities:

1 – intrusion

2 – overturning

3 - faults

Unconformity• Unconformity-

•A break or an irregularity in the geologic time sequence due to a geologic event.

•“Missing Information”

1. Intrusion• A intrusion is igneous rock that cuts

through layers of sedimentary rock. The intrusion is younger than any other rock layer it cuts through.

intrusion

2. Overturning• Overturning is when rock layers

are folded due to gravity, erosion, or shifts in Earth’s crust

3. Faults• Faults are cracks, fractures or shifts in

Earth’s crust

Fault

Law of Superposition Practice

Which type of unconformity do you see in the diagram?

Can you put the layers in order from oldest to youngest?

Law of Superposition Practice

Which types of unconformity do you see in the diagram?

Can you put the layers in order from youngest to oldest?

What is This?

Fossils• Fossil – traces or remains of living

things from long ago that help sort out the sedimentary rock record

• Index Fossils – fossils that are used as a “reference” to date other fossils

Types of Fossils

• BrainPOP Video

Fossil Samples

• Decide which type of fossil each sample is:

Homework• Vocab Set 2 – Days 1 & 2

• Other Ways of Determining Reading Comprehension with Questions (if not finished in

class)

Warm-Up• Update your Table of Contents• Get your vocabulary cards out to be checked

(remember I’m checking days 1 & 2)• Tape “Other Ways of Determining Age” into

page 16 of your Interactive NotebookDate Session

#Activity Page

#

9/17 8 “Other Ways of Determining Age” Reading Comprehension

16

Determining Age Note Guide 17

Silent Stations Skill Practice Answer Sheet 18

Review

• What were some things we talked about last class that help us determine how old

Earth really is?

The Butler walks to workThe Handyman rides a bikeThe Cook rides a motorcycleThe Maid drives a carThe Nephew has a seeing-eye dog

395241678

Time for more specific evidence…

Relative Age• Relative Age - the age of an event or

object in relation to other events or objects

–Use words like older, younger, around the same time, etc…

Absolute Age• Absolute Age - The actual age of an

event or object– Use techniques to figure out actual age

• Radioactive dating, carbon dating

Lived:

1 million years ago

2 million years ago

3 million years ago

4 million years ago

Types of Dating• Radioactive (Radiometric) Dating – If you

know how much radioactive materialwas initially present in the sample and you know the half-life of thematerial, you can calculate the age of the sample.

• Carbon Dating – Using the amount of carbon in fossil remains to determine the age - sample must have been alive to use carbon dating!

What’s a “half-life?”• Half-life – the length

of time it takes for half of the atoms in a sample of a radioactive material to change

• This break down occurs at a constant rate depending on the substance

Types of Dating

• BrainPOP Video – Carbon Dating

• Half-life Practice

Questions??

“SILENT STATIONS”

Be sure to tape the station guide into your notebook!

Homework•Vocab Set 2 – Day 3

Warm-Up• Update your Table of Contents for today’s

activities• Get your vocab cards out to be checked• Review your “Silent Stations” guide and

see if you have any questions

Date Session#

Activity Page#

9/19 9 Ice Cores & Tree Rings – Notes and Lab 19

Vocab Set 2 Practice Quiz 20

Homework: Argumentative Writing Prompt 21

Homework: Argumentative Writing Prompt

COPY NOW ONTO PAGE 21!

Analyze the information you have learned about ice cores and tree rings and answer the following:

Which of the two tools is more useful?

Defend your answer using 3 pieces of evidence to support your decision.

“Silent Stations”

• Take the first 20 minutes to complete your remaining stations.

• I am the “Answer Key” station if you are finished and would like to check your answers to make corrections

Just a Few More Pieces of Evidence…

We’ve already talked about:• Law of Superposition• Unconformities (Intrusion, Overturning, Fault)• Fossils/Index Fossils• Absolute & Relative Age• Carbon Dating & Radioactive Dating

We are missing:• Ice Cores• Tree Rings

Remember The Law of Uniformitarianism?

• The earth is a constantly changing place.• Climate change is part of that and the

climate can gradually change over hundreds, thousands or millions of years.

• Ice cores and tree rings are tools to help scientists figure out how the climate has changed in the past.

Ice Cores• Ice Core- a tubular

sample of ice that shows the layers of snow and ice that have built up over thousands of years literally freezing the events of the past

What types of things do you think get “trapped” in these ice cores?

What types of things do you think get “trapped” in these ice cores?

• local temperature records• atmospheric composition data • dust, ash or sediment• plant spores• bubbles of gas or radioactive material* All of this information together presents a

well rounded picture

Ice Cores

• Video Clip at Discovery Education:

http://player.discoveryeducation.com/index.cfm?guidAssetId=179C023D-B3CE-46A6-BECD-FB5978AB7A01&blnFromSearch=1&productcode=US

Tree Rings

• Another tool for studying climate change over the life span of the tree

• The width of tree rings varies, depending on how much the tree grows in various years

• Thick ring= good year for growth• Thin ring= poor growth, little rainfall

Tree Ring Practice

B

A

C

D

Tree Ring & Ice Core Lab

Everyone needs to follow directions and act appropriately!!

• One person in your group needs to be in charge of getting supplies

• One person in your group needs to be in charge of disposal/return of supplies

• One person needs to be in charge of making sure everyone is writing the answers

• One person needs to be in charge of answering questions for your group (spokesperson)

DECIDE YOUR ROLES NOW

Homework

• Vocabulary Set 2 Practice Quiz

• Argumentative Writing Prompt