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

4 th Quarter Table of Contents 1 TitleAssignment # Ice Cores2 Ice Core Webquest3 Fossil Notes4 Getting into the Fossil Record 5 Fossil Vocab6 Fossils over Time (Molds vs Casts) 7 Law of Superposition Vocab 8 Who’s on First? (Wkst)9 Geologic Time VOCAB 10

Law of Superposition VOCAB8 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 Monday Complete 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. 1. Copy the first 3 columns of the Geologic Time Scale on page 336 into your notebook on page 7 1. 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: ERAPERIODMILLIONS of YEARS AGO Picture/Sketch of Organism CenozoicQuaternary1.8 Tertiary66.4 Cretaceous104 MesozoicJurassic208 Triassic245 PaleoziocPermian286 Carboniferous360 Devonian408 Silurian438 Ordovician505 Cambrian544 Precambrian544 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 shells 6. How have the Brachiopods shells evolved over time? 7. Describe the different Trilobite 8. How have the Trilobites evolved over time? 9. Why might the Trilobites be curled up? 10. Would these “fossils” be molds or casts?

Geologic Time Vocab10  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?