8. Geologic Time

Essential Question: How do rock layers and fossils provide a record of Earth’s geologic history & the evolution of life?

Learning Target: I can analyze how rock layers and fossils provide evidence of Earth’s history

Learning Task: I will interpret data and draw conclusions for rock layers.

I will correctly sort Geologic Vocab.

I will understand how fossils show Earth’s continents movements.

Welcome! Warm Up Wednesday 4/10/13 Week of 4/7 – 4/11

What is an index fossil?

How are they important to relative dating?

Record your response at www.goo.gl/vta7d1

4th Quarter Table of Contents 1

Title Assignment #Ice Cores 2

Ice Core Webquest 3

Fossil Notes 4

Getting into the Fossil Record 5

Fossil Vocab 6

Fossils over Time (Molds vs Casts) 7

Law of Superposition Vocab 8Who’s on First? (Wkst)

9Geologic Time VOCAB 10

Law of Superposition VOCAB 8• Law of superposition – the idea that rocks and fossils found in

lower layers are older than the rocks and fossils found in the top layers

• relative dating – a method of dating rocks which can’t give us an actual age, but can tell us whether a rock layer is older or younger than another

• strata – a certain rock layer • unconformity - gaps in rock layers and/or the fossil record • intrusion - a rock layer that forms when magma hardens beneath

Earth’s surface • extrusion - a rock layer that forms when lava flows onto Earth’s

surface and hardens • radiometric dating – using radioactive elements found naturally in

substances in order to determine how old they are.• absolute age – the actual age of a rock or fossil

Fossils over time (Molds vs Casts) 7

Let’s look at our Molds and Casts from MondayComplete Day 2 of of the Document,

Google Drive: 5.Molds vs Casts Worksheet:

Take picture of your casts and insert into your document.

Upload your document to your Science Folder(DO NOT share it with me, just put it in your

folder!!!)

Fossils over time (Molds vs Casts) 7

1. Using the chart on page 336 of your book and your Fossil Guide, arrange the 8 fossils in your tray in order based on the Period of time when they lived.

2. Copy the first 3 columns of the Geologic Time Scale on page 336 into your notebook on page 7

3. Next to the respective Periods, draw the appropriate fossil and label its name as given on the Fossil Guide

Example of what the chart you create in your notebook might look like:

ERA PERIOD MILLIONS of YEARS AGO

Picture/Sketch of Organism

Cenozoic Quaternary 1.8

Tertiary 66.4

Cretaceous 104

Mesozoic Jurassic 208

Triassic 245

Paleozioc Permian 286

Carboniferous 360

Devonian 408

Silurian 438

Ordovician 505

Cambrian 544

Precambrian 544 million years ago- 4.6 billion years ago

Example of what the chart you create in your notebook might look like:

Answer the Questions about the fossils

1. Which “fossil” is the oldest?2. Which “fossil” is the youngest?3. Describe the different Ammonites 4. How have the Ammonites evolved over time?5. Describe the different Brachiopod shells6. How have the Brachiopods shells evolved over

time?7. Describe the different Trilobite8. How have the Trilobites evolved over time?9. Why might the Trilobites be curled up?10. Would these “fossils” be molds or casts?

http://goo.gl/Vt2UvN

Geologic Time Vocab 10

Geologic Time Scales - a record of the life forms and geologic events in Earth’s history

Era - a unit of geologic time that includes two or more periods

Period - a subdivision of an era

Continental Drift - the theory that states that the gradual shifting of Earth’s plates causes continents to move over time

Pangaea - The name of the big landmass that broke apart into the current continents

Plate Tectonics - large pieces of the Earth’s outermost layer (called tectonic plates) move and change shape

Getting into the Fossil Record 5 Finish this and/or your ice cores

webquest!

Exit Ticket

What is the Law of Superposition?