Earth’s Age + Evidence

WARM UP• Write your homework – leave it to be

stamped!• Get your homework out to be checked!• Update your Table of Contents for today!• Get something to grade your Vocab Quiz

with!Date Session

#Activity Page

#11/15 & 11/18

7 Earth’s Age & Evidence Note guide 13

The Great Fossil Find Poster Instructions 14

Notes Tips for Today• Anything in yellow you MUST write

on your note guide• Pictures and diagrams are great

things to 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 in the next few lessons 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 go

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• An 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 – common fossils that are used as a “reference” to date other fossils

Types of Fossils• BrainPOP Video

The Great Fossil Find• Choose a partner to work with…I will give

you 1 minute to move all of your stuff so that you are sitting with your partner and be ready to listen!

• Work together to determine what type of animal your fossil is! The activity guide must be turned in by the end of class!

http://www.indiana.edu/~ensiweb/lessons/gr.fs.fd.html

Homework1. Bring a bag of

Skittles next class!

2. The Great Fossil Find Poster due in 2 classes!

Warm-Up• Write your homework – get it stamped!• Update your Table of Contents for today!• Make sure you have a cup of Skittles – you

may need to arrange for someone to share with you!

Date Session#

Activity Page#

11/19 & 11/20

8 Determining Age Note Guide 15

Skittles Half-Life Simulation 16

“Other Ways of Determining Age” Reading Comprehension & Activity

17

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

R

(layer E)

395241678

R

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 material was initially present in the sample and you know the half-life of the material, you can calculate the age of the sample.

• Carbon Dating – Using the amount of carbon in fossil remains, and the half life 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

Carbon Dating• BrainPOP Video – Carbon Dating

• Half-life Practice

Skittles Half-Life Simulation

• You will work where you are seated, but you and your table partner can work together.

• I want to see your work before you leave, and I will be checking it off for a grade…then you can tape it into page 16!

Homework• The Great Fossil Find

Poster – due next class!• Finish the “Other Ways of

Determining Age” Reading, Questions & Activity – due in 2 classes!

Warm-Up• Write a homework reminder – get it

stamped!• Update your Table of Contents for today!• Put your Great Fossil Find Poster in the

basket!• Get your Skittles Lab out from last class!

Date Session#

Activity Page#

11/21 & 11/22

9 Silent Stations Answer Sheet – FORMAL GRADE

18

Skittles Half-Life Simulation Review

#2 on the back• What is Iodine-131?

# of Half-Lives Time of Half-Life Amount of Iodine-131 Remaining

0 0 40 mg

1 8 days 20 mg

2 16 days 10 mg

3 24 days 5 mg

4 32 days 2.5 mg

Skittles Half-Life Simulation Review#3 on the back:

• Does it give the name of the radioactive isotope in the question?

• What does it mean to be radioactive?• What is an isotope?• What is a half-life? What is the half-life of

this isotope?• What is the significance of this half-life –

in other words, why should your mom not be worried?

READY TO FIND OUT WHAT THE GREAT FOSSIL FIND WAS?• Scaphognathus crassirostris was a

pterosaur, similar to a pterodactyl, that lived during the Late Jurassic Period.

Scaphognathus crassirostris

• What it may have looked like…

“SILENT STATIONS”• You will rotate around the room quietly and

practice the concepts we have learned at each station.

• I am the “Answer Key Station,” so once you have completed everything you can come check your answers!

• Be sure to tape the station guide into your notebook on page 18 once you have checked your answers and been checked off for a grade!

• Complete the homework for next class, or work on an extra credit opportunity!!

HOMEWORK• “Other Ways of Determining Age” –

Article, Questions & Map Activity due next class!

• Extra Credit Opportunity – try to finish it by after Thanksgiving break so you don’t forget about it!

Warm-Up• No homework over break!• Update your Table of Contents today!• Get your “Other Ways of Determining Age”

out to be checked!• If you haven’t shown me your Silent

Stations you need to have those out as well!Date Session

#Activity Page

#11/25 & 11/26

10 Ice Cores & Tree Rings – Notes and Lab

19

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?

Ice Cores• temperature records• atmospheric composition data • dust, ash or sediment• plant spores• bubbles of gas (usually CO2)

Pros and Cons?

Ice Cores

• Extreme Ice National Ice Core Lab

http://natgeotv.com/ca/extreme-ice/videos/national-ice-core-lab

http://earththeoperatorsmanual.com/segment/5

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

Pros and Cons?

Tree Ring Practice

B

A

C

D

Lord of the Tree Rings

• http://www.youtube.com/watch?v=FAOYkx8E-Gc

Ice Core & Tree Ring Lab Roles• Supply Manager – retrieves and returns

supplies• Reader/Discussion leader – reads the

directions and the questions and ensures there is a discussion

• Scribe – makes sure everyone knows what to write, and is writing

• Speaker – shares information with the class

Ice Core Lab• Send your supply manager to get a

piece of paper towel from one of the sinks.

• Your group will receive 1 ice core sample - peel the paper off and follow the directions!

• Be sure to answer all of the questions and be ready to share in 5 minutes!

Tree Ring Lab• Send your supply manager to your sink

and simply set your ice core in the sink to melt – throw away the paper towel!

• Your group will receive several tree ring samples – read and follow the directions!

• Be sure to answer all of the questions!• After everyone has finished, have your

supply manager return ALL tree rings!

Chromebook LoginStudents Log-In Directions:

Username: flast1234@cms.gaggle.net(first initial of first name + full last name + last 4 of student ID)Password: YYMMDD (birthday)Go To: drive.google.com

Google Doc Directions• Once you go to the Google Drive you

should already be logged in (your username will be in the upper right corner)

• On the left – click on “Shared With Me”• You should see one document named

Ice Cores Vs. Tree Rings (and your block)

• Click on it to open it

Google Doc Directions• Back out of the “Shared Document”

• On the left hand side, click on “Create” and then choose “Document”

• Type your response in your own document and then copy and paste it into the class document OR you can share just with me by clicking on “Share” in the upper right and type in my name…SHARE WITH MY CMS.K12.NC.US EMAIL ADDRESS!

Google Docs Argumentative Writing

PromptAnalyze the information you have learned

today, and researched about ice cores and tree rings to construct an argumentative paragraph (10 sentences minimum):

1) Opinion/Argument: Which of the two tools is more useful and why – use 3 reasons to support your opinion?

2) Research: Defend your answer using research from 1 cited resource!

Questions??

The Birth of the Earth• http://www.youtube.com/watch?v=JQ93Ms

M8KFI

• A great recap as well as a lot we didn’t get a chance to talk about!