Bellwork Name 5 ways humans USE land Explain the difference between water supply and water quality What do we mean when we say water is a vital substance What causes eutrophication

After the test: Put your answer sheet face down on your desk on top of your test booklet Create a title page for the next chapter: EARTH’S HISTORY On this page include the following: pg 260-270 A drawing of a trilobite Definition and drawing of the law of superposition Definition of relative age Picture of an unconformity Definition of absolute age Use the paragraph on radioactive decay to draw and label the parts of an atom.

Bellwork Finish your title page: (p260-270) A drawing of a trilobyte Definition and drawing of the law of superposition Definition of relative age Picture of an unconformity Definition of absolute age Use the paragraph on radioactive decay to draw and label the parts of an atom Name 2 ways earth’s surface can show a change over time Do you think a piece of pottery is a fossil? Why or Why not? T/F 3. Once rock forms it never changes 4. Fossils can tell us which animals lived at certain times A volcano erupting is an example of a geologic process

Earth’s History

Geologic Change Over Time EQ: How do we learn about Earth’s History? Obj: SC.7.E.6.4 I can explain how we learn about earth’s history because I can describe types of evidence in rocks, fossils and ice.

What is the theory of uniformitarianism? Theory that states that geological processes that happened in the past can be explained by processes that happen now EX: the way a volcano behaves today is the same as how it behaved in the past. erosion works the same now as it did in the past.

How do organisms become fossils? Fossil: the trace or remains of an organism that lived long ago Organisms can be preserved as fossils in 5 ways:

1. Trapped in Amber Insects get trapped in sap from evergreen trees and covered Preserves the body from decay

2. Trapped in Asphalt (tar pits) Organisms became trapped in the tar when they came to drink the water and got stuck in the pits. The oily tar seeps into bones and protects tham from decay Preserves organisms with little or no change.

3. Buried in Rock Organisms die and are quickly buried by sediment Hard parts of animals are preserved in the rock as sediments harden.

How do organisms become fossils?

4. Frozen in ice Preserves hair and skin.

5. Petrified When an organisms tissues are replaced by minerals.

What are Trace Fossils? Fossils that form in sedimentary rock due to kinds of animal activity Ex: Tracks, burrows, coprolite Mold fossils – (imprints) hollow area in sediment in the shape of the organism Cast fossils – copy of the shape of the organism made when water and sediment seep into the mold to form a cast.

Identify the type of preserved remains

What can the fossil record tell us Fossil record: all fossils found on Earth Show: Environmental changes over time (fish fossils=water) How life forms have changed over time

What evidence shows earths climate history? Tree rings: Thick = favorable climate for growth Sea floor sediments – cylinders of sea floor sediment show type of organisms that were present depending on climate Ice cores – long cylinder of ice. A band forms each year. Thick = lots of precipitation

Exit: What do these types of evidence tell us about earth’s history Shark tooth on top of a mountain? A rock from a mountain on 2 different continents has the same age and composition? A very wide band on an ice core? A small ring on a tree trunk

Bellwork - Friday Name 5 ways an organism’s remains can be preserved Describe the difference between a cast and a mold Fossil sea shells have been found in rock beds on land. What can you infer about how the area has changed? Name 3 ways we can learn about earths climate history. Describe the steps in formation of a rock fossil using each picture below.

Complete the Tracks activity from front table and turn in to the correct folder in the trays in back Answer the questions on the Back. THERE IS NOT ENOUGH SPACE ON THE FRONT. It is graded, do it alone!

EQ: How is the relative age of rock Measured? Obj: Explain how scientist measure the relative age of rocks and identify gaps in the rock record

How is the relative age of rock measured? Relative dating – determining whether 1 object or event is younger or older than another Does not tell the actual age of object in years. You can tell the oldest and youngest, but can you tell the years these phones were made?

How are undisturbed rock layers dated? The Law of Superposition: Younger rocks lie above older rocks if the layers have not been disturbed.

How are rock layers disturbed? 1. Unconformity –a break in the rock record (missing layer) 2. folding 3. Faults 4. Intrusions – when magma seeps into a rock layer and cools – always newer than the rock they go through.

Order the rock layers from newest to oldest.

How do fossils determine relative age? Fossilized organisms can be arranged by changes over time Index fossils: Fossils that help tell relative age of rock layers they are in Needs to be found all over Around for only a short period of time A lot of them EX: Trilobites

Horseshoe crabs are common in the ocean along the east coast Horseshoe crabs are common in the ocean along the east coast. They have exisited for 200 million years with very little change. Would they be a good index fossil? Why or why not?

Using fossil charts to find relative ages of rock layers. Fossil range charts can show the length of time organisms have been found in the fossil record. By finding which rocks are present in a given sample, scientists can narrow down the relative age of the rock. imagine that there has been a fire in the library at a local High School. The librarian is trying to reconstruct what’s left of the yearbooks and has come upon a pile of pages with photographs on them. She made the chart below that shows the names of the teachers along the Y axis and the Years they have taught at the school on the X axis. Use the fossil range chart to answer the following questions. .

One of the photos has Mr. X, Ms. Y, and Mrs. Z in it One of the photos has Mr. X, Ms. Y, and Mrs. Z in it. What year was it from? How do you know? If you find a photo with Mr. X, Mrs. Z, and Miss Q. What year is it from? If you find a photo that has Mr. X, Ms. Y but not Mrs. Z, what year is it from? Does the fact that Ms. Z is missing mean anything?

Which layer of rock was formed first Which layer was formed last Which 2 layers appear to be the same age? Which layer shows an unconformity?

bellwork Which is the oldest rock layer in the diagram? Explain why the rock layers on the west side of the rock layers do not match the east side. Which is the younger layer, layer A or layer C? How do you know. What kind of rock is probably found at A. What is A called? Describe the formation of the fossil at right.

Relative age of Fossils Lab - Hints Read the introduction and complete the 5 questions at the bottom of the page. We are in the Quaternary Time period Your green textbook Chapter 9 may have a diagram of the geological time scale if you need help with geological time. Mistakes to fix: Amonites start at Triassic Orthocone go from Ordivician to Triassic