How to Use This Presentation • To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show.” • To advance through the presentation, click the right-arrow key or the space bar. • From the resources slide, click on any resource to see a presentation for that resource. • From the Chapter menu screen click on any lesson to go directly to that lesson’s presentation. • You may exit the slide show at any time by pressing the Esc key. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Resources Bellringers Chapter Presentation Transparencies Standardized Test Prep Visual Concepts Image and Math Focus Bank Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 The Rock and Fossil Record Table of Contents Section 1 Earth’s Story and Those Who First Listened Section 2 Relative Dating: Which Came First? Section 3 Absolute Dating: A Measure of Time Section 4 Looking at Fossils Section 5 Time Marches On Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 1 Earth’s Story and Those Who First Listened Bellringer “The Present Is the Key to the Past.” This phrase was the cornerstone of the uniformitarianist theory developed by geologist James Hutton in the late 1700s. Write a few sentences in your science journal about how studying the present could reveal the story of Earth’s history. Use sketches to illustrate processes that occurred millions of years ago that you can still see today. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 1 Earth’s Story and Those Who First Listened Objectives • Compare uniformitarianism and catastrophism. • Describe how the science of geology has changed over the past 200 years. • Explain the role of paleontology in the study of Earth’s history. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 1 Earth’s Story and Those Who First Listened The Principle of Uniformitarianism • Scientist James Hutton, the author of Theory of the Earth, proposed that geologic processes such as erosion and deposition do not change over time. • Uniformitarianism is the idea that the same geologic processes shaping the Earth today have been at work throughout Earth’s history. • The next slide shows how Hutton developed the idea of uniformitarianism. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 1 Earth’s Story and Those Who First Listened Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 1 Earth’s Story and Those Who First Listened The Principle of Uniformitarianism, continued • Uniformitarianism Versus Catastrophism Hutton’s theories sparked a scientific debate by suggesting the Earth was much older than a few thousand years, as previously thought. • A few thousand years was not enough time for the gradual geologic processes that Hutton described to have shaped the planet. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 1 Earth’s Story and Those Who First Listened The Principle of Uniformitarianism, continued • A Victory for Uniformitarianism Catastrophism was geology’s guiding principle until the work of geologist Charles Lyell caused people to reconsider uniformitarianism. • Lyell published Principles of Geology in the early 1830s. Armed with Hutton’s notes and new evidence of his own, Lyell successfully challenged the principle of catastrophism. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 1 Earth’s Story and Those Who First Listened Modern Geology -- A Happy Medium • During the late 20th century, scientists such as Stephen J. Gould challenged Lyell’s uniformitarianism. They believed that catastrophes occasionally play an important role in shaping Earth’s history. • Today, scientists realize that most geologic change is gradual and uniform, but catastrophes that cause geologic change have occurred during Earth’s long history. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 1 Earth’s Story and Those Who First Listened Paleontology -- The Study of Past Life • The history of the Earth would be incomplete without knowledge of the organisms that have inhabited our planet and the conditions under which they lived. • The science involved with the study of past life is called paleontology. • Paleontologist study fossils, which are the remains of organisms preserved by geologic processes. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Bellringer Arrange the following sentences in a logical order to make a short story: I stood in the checkout line. I selected two apples. I walked home from the store. I gave the cashier money. I went to the store. The cashier gave me change. I was hungry. Write your story in your science journal. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Objectives • Explain how relative dating is used in geology. • Explain the principle of superposition. • Describe how the geologic column is used in relative dating. • Identify two events and two features that disrupt rock layers. • Explain how physical features are used to determine relative ages. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? The Principle of Superposition • Geologists try to determine the order in which events have happened during Earth’s history. They rely on rocks and fossils to help them in their investigation. • The process of determining whether an event or object is older or younger than other events or objects is called relative dating. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? The Principle of Superposition, continued • Layers of sedimentary rock, such as the ones shown below, are stacked like pancakes. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? The Principle of Superposition, continued • As you move from the top to the bottom in layers of sedimentary rock, the lower layers are older. • Superposition is a principle that states that younger rocks lie above older rocks, if the layers have not been disturbed. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? The Principle of Superposition, continued • Disturbing Forces Not all rock sequences are arranged with the oldest layers on the bottom and the youngest layers on top. • Some rock sequences have been disturbed by forces within the Earth. • These forces can push other rocks into a sequence, tilt or fold rock layers, and break sequences into moveable parts. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? The Geologic Column • The geologic column is an ideal sequence of rock layers that contains all the known fossils and rock formations on Earth, arranged from oldest to youngest. • Geologists use the geologic column to interpret rock sequences and to identify the layers in puzzling rock sequences. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Disturbed Rock Layers • Geologists often find features that cut across existing layers of rock. • Geologists use the relationships between rock layers and the features that cross them to assign relative ages to the features and the layers. • The features must be younger than the rock layers because the rock layers had to be present before the features could cut across them. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Disturbed Rock Layers, continued • Events That Disturb Rock Layers Geologists assume that the way sediment is deposited to form rock layers — in horizontal layers — has not changed over time. • If rock layers are not horizontal, something must have disturbed them after they formed. • The next slide describes four ways that rock layers may become disturbed. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Disturbed Rock Layers, continued • A fault is a break in the Earth’s crust along which blocks of the crust slide relative to one another. • An intrusion is molten rock from the Earth’s interior that squeezes into existing rock and cools. • Folding occurs when rock layers bend and buckle from Earth’s internal forces. • Tilting occurs when internal forces in the Earth slant rock layers. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Gaps in the Record -- Unconformities • Missing Evidence Sometimes, layers of rock are missing, creating a gap in the geologic record. Missing rock layers create breaks in rock-layer sequences called unconformities. • An unconformity is a break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Types of Unconformities • Most unconformities form by both erosion and nondeposition, but other factors may be involved. • To simplify the study of unconformities, geologists place them into three major categories: disconformities, nonconformities, and angular unconformities. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Types of Unconformities, continued • Disconformities exist where part of a sequence of parallel rock layers is missing. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Types of Unconformities, continued • Nonconformities exist where sedimentary rock layers lie on top of an eroded surface of nonlayered igneous or metamorphic rock. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Types of Unconformities, continued • Angular Unconformities exist between horizontal rock layers and rock layers that are tilted or folded. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Rock-Layer Puzzles • Rock-layer sequences often have been affected by more than one geological event or feature. • For example, intrusions may squeeze into rock layers that contain an unconformity, as shown at right. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 2 Relative Dating: Which Came First? Rock-Layer Puzzles, continued • Determining the order events that led to a sequence that has been disturbed by more than one rockdisturbing feature is like solving a jigsaw puzzle. • Geologists must use their knowledge of the events that disturb rock-layer sequences to piece together the history of the Earth. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Bellringer Do the following statements describe relative or absolute age? 1. She is my younger sister. 2. He is 12 years old. Why do geologists use both absolute and relative dating to interpret the past? Why are both absolute and relative dates valid dates for geologists, and other earth scientists to use? Write a paragraph in your science journal. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Objectives • Describe how radioactive decay occurs. • Explain how radioactive decay relates to radiometric dating. • Identify four types of radiometric dating. • Determine the best type of radiometric dating to use to date an object. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Radioactive Decay • Absolute dating is any method of measuring the age of an event or object in years. • To determine the absolute ages of fossils and rocks, scientists analyze isotopes of radioactive elements. • Atoms of the same element that have the same number of protons but different numbers of neutrons are called isotopes. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Radioactive Decay, continued • Most isotopes are stable, meaning that they stay in their original form. • Other isotopes are unstable. Scientists call unstable isotopes radioactive. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Radioactive Decay, continued • Radioactive isotopes tend to break down into stable isotopes of the same or other elements in a process called radioactive decay. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Radioactive Decay, continued • Because radioactive decay occurs at a steady rate, scientists can use the relative amounts of stable and unstable isotopes present in an object to determine the object’s age. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Radioactive Decay, continued • Dating Rocks — How Does It Work? In radioactive decay, an unstable radioactive isotope of one element breaks down into a stable isotope. The stable isotope may be of the same element or of a different element. •The unstable radioactive isotope is called the parent isotope. • The stable isotope produced by the radioactive decay of the parent isotope is called the daughter isotope. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Radioactive Decay, continued • The rate of radioactive decay is constant, so scientists can compare the amount of parent material with the amount of daughter material to date rock. • The more daughter material there is, the older the rock is. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Radiometric Dating • Determining the absolute age of a sample, based on the ratio of parent material to daughter material is called radiometric dating. • If you know the rate of decay for a radioactive element in a rock, you can figure out the absolute age of the rock. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Radiometric Dating, continued • A half-life is the time needed for half of a sample of a radioactive substance to undergo radioactive decay. • After every half-life, the amount of parent material decrease by one-half. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Types of Radiometric Dating • Scientists use different radiometric-dating methods based on the estimated age of an object. There are four radiometric-dating techniques. • Potassium-Argon Method Potassium-40 has a halflife of 1.3 billion years, and it decays leaving a daughter material of argon. • This method is used mainly to date rocks older than 100,000 years. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Types of Radiometric Dating, continued • Uranium-Lead Method Uranium-238 is a radioactive isotope with a half-life of 4.5 billion years. Uranium-238 decays in a series of steps to lead-206. • The uranium-lead method can be used to date rocks more than 10 million years old. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Types of Radiometric Dating, continued • Rubidium-Strontium Method The unstable parent isotope rubidium-87 forms a stable daughter isotope strontium-87. • The half-life of rubidium-87 is 49 billion years. This method is used for rocks older than 10 million years. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Types of Radiometric Dating, continued • Carbon-14 Method Carbon is normally found in three forms, the stable isotopes carbon-12 and carbon-13, and the radioactive isotope carbon-14. • Living plants and animals contain a constant ratio of carbon-14 to carbon-12. Once a plant or animal dies, no new carbon is taken in. The amount of carbon-14 begins to decrease as the plant or animal decays. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 3 Absolute Dating: A Measure of Time Types of Radiometric Dating, continued • The half-life of carbon-14 is 5,730 years. • The carbon-14 method of radiometric dating is used mainly for dating things that lived within the last 50,000 years. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Bellringer Describe the fossil record of your own life that might be found 65 million years from now. What items, or artifacts, might be likely to survive? What kinds of things would decay and disappear? Do you think your fossil record would produce an accurate picture of your life? What might be missing? Write your description in your science journal. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Objectives • Describe five ways that different types of fossils form. • List three types of fossils that are not part of organisms. • Explain how fossils can be used to determine the history of changes in environments and organisms. • Explain how index fossils can be used to date rock layers. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Fossilized Organisms • The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock is called a fossil. • Fossils are most often preserved in sedimentary rock, but other materials can also preserve evidence of past life. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Fossilized Organisms, continued • Fossils in Rocks When an organism dies, it either begins to decay or is consumed by other organisms. Sometimes dead organisms are quickly buried by sediment, which slows down decay. • Shells and bones are more resistant to decay than soft tissues, so when sediments become rock, the harder structures are more commonly preserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Fossilized Organisms, continued • Fossils in Amber Organisms occasionally become trapped in soft, sticky tree sap, which hardens and becomes amber. • Insect fossils have often been preserved in this way, but frogs and lizards have also been found in amber. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Fossilized Organisms, continued • Petrifaction is a process in which minerals replace and organism’s tissues. • One form of petrifaction is called permineralization, a process in which the pore space in an organism’s hard tissue is filled up with mineral. • Replacement is a process in which an organism’s tissues are completely replaced by minerals. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Fossilized Organisms, continued • Fossils in Asphalt There are places where asphalt wells up at the Earth’s surface. These thick, sticky pools can trap and preserve organisms. • Frozen Fossils Since cold temperatures slow down decay, many types of fossils have been found preserved in ice. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Other Types of Fossils • Trace Fossils are naturally preserved evidence of animal activity. Preserved animal tracks are an example of a trace fossil. • Other types of trace fossils include preserved burrows or shelters that were made by animals, and coprolite, which is preserved animal dung. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Other Types of Fossils, continued • Molds and Casts are two more examples of fossils. • A mold is a mark or cavity made in a sedimentary surface by a shell or other body. • A cast is a type of fossil that forms when sediments fill the cavity left by a decomposed organism. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Using Fossils to Interpret the Past • The Information in the Fossil Record The fossil record offers only a rough sketch of the history of life on Earth. The fossil record is incomplete because most organisms never became fossils. • Scientists know more information about organisms that had hard body parts and that lived in environments that favored fossilization. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Using Fossils to Interpret the Past, continued • History of Environmental Changes The fossil record reveals changes in an area’s climate over time. By using the fossils of plants and land animals, scientists can reconstruct past climates. • History of Changing Organisms By studying the relationships between fossils, scientists can interpret how life has changed over time. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Using Fossils to Date Rocks • Scientists have learned that particular types of fossils appear only in certain layers of rock. • By dating the rock layers above and below these fossils, scientists can determine the time span in which the organisms that formed the fossils lived. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Using Fossils to Date Rocks, continued • If a type of organism existed for only a short period of time, its fossils would show up in a limited range of rock layers. These fossils are called index fossils. • Index fossils are fossils that are found in the rock layers of only one geologic age, and can be used to establish the age of the rock layers. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Using Fossils to Date Rocks, continued • Ammonites An example of an index fossil is the fossil of a genus of ammonites called Tropites. • Tropites, a marine mollusk similar to a modern squid, lived between 230 million and 208 million years ago. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Section 4 Looking at Fossils Using Fossils to Date Rocks, continued • Trilobites Fossils of a genus of trilobites called Phacops are another example of an index fossil. • Trilobites are extinct and lived approximately 400 million years ago. When scientists find Phacops in a rock, they assume that the rock is approximately 400 million years old. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Chapter 6 Show Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Reading Read each of the passages. Then answer the questions that follow each passage. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Passage 1 Three hundred million years ago, the region that is now Illinois had a different climate than it does today. Swamps and shallow bays covered much of the area. No fewer than 500 species of plants and animals lived in this environment. Today, the remains of these organisms are found beautifully preserved within nodules. Continued on the next slide Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Passage 1, continued Nodules are round or oblong structures usually composed of cemented sediments that sometimes contain the fossilized hard parts of plants and animals. The Illinois nodules are exceptional because the soft parts of organisms are found together with hard parts. For this reason, these nodules are found in fossil collections around the world. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 1. In the passage, what is the meaning of the word exceptional? A beautiful B extraordinary C average D large Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 1. In the passage, what is the meaning of the word exceptional? A beautiful B extraordinary C average D large Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 2. According to the passage, which of the following statements about nodules is correct? F Nodules are rarely round or oblong. G Nodules are usually composed of cemented sediment. H Nodules are not found in present-day Illinois. I Nodules always contain fossils. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 2. According to the passage, which of the following statements about nodules is correct? F Nodules are rarely round or oblong. G Nodules are usually composed of cemented sediment. H Nodules are not found in present-day Illinois. I Nodules always contain fossils. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 3. Which of the following is a fact in the passage? A The Illinois nodules are not well known outside of Illinois. B Illinois has had the same climate throughout Earth’s history. C Both the hard and soft parts of organisms are preserved in the Illinois nodules. D Fewer than 500 species of plants and animals have been found in Illinois nodules. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 3. Which of the following is a fact in the passage? A The Illinois nodules are not well known outside of Illinois. B Illinois has had the same climate throughout Earth’s history. C Both the hard and soft parts of organisms are preserved in the Illinois nodules. D Fewer than 500 species of plants and animals have been found in Illinois nodules. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Passage 2 In 1995, paleontologist Paul Sereno and his team were working in an unexplored region of Morocco when they made an astounding find — an enormous dinosaur skull! The skull measured approximately 1.6 m in length, which is about the height of a refrigerator. Given the size of the skull, Sereno concluded that the skeleton of the animal it came from must have been about 14 m long — about as big as a school bus. Continued on the next slide Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Passage 2, continued The dinosaur was even larger than Tyrannosaurus rex! The newly discovered 90 million-year-old predator most likely chased other dinosaurs by running on large, powerful hind legs, and its bladelike teeth meant certain death for its prey. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 1. In the passage, what does the word astounding mean? A important B new C incredible D one of a kind Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 1. In the passage, what does the word astounding mean? A important B new C incredible D one of a kind Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 2. Which of the following is evidence that the dinosaur described in the passage was a predator? F It had bladelike teeth. G It had a large skeleton. H It was found with the bones of a smaller animal nearby. I It is 90 million years old. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 2. Which of the following is evidence that the dinosaur described in the passage was a predator? F It had bladelike teeth. G It had a large skeleton. H It was found with the bones of a smaller animal nearby. I It is 90 million years old. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 3. What types of information do you think that fossil teeth provide about an organism? A the color of its skin B the types of food it ate C the speed that it ran D the mating habits it had Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 3. What types of information do you think that fossil teeth provide about an organism? A the color of its skin B the types of food it ate C the speed that it ran D the mating habits it had Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Math Read each question and choose the best answer. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 1. Carbon-14 is a radioactive isotope with a half-life of 5,730 years. How much carbon-14 would remain in a sample that is 11,460 years old? A 12.5% B 25% C 50% D 100% Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 1. Carbon-14 is a radioactive isotope with a half-life of 5,730 years. How much carbon-14 would remain in a sample that is 11,460 years old? A 12.5% B 25% C 50% D 100% Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 2. If a sample contains an isotope with a half-life of 10,000 years, how old would the sample be if 1/8 of the original isotope remained in the sample? F 20,000 years G 30,000 years H 40,000 years I 50,000 years Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 2. If a sample contains an isotope with a half-life of 10,000 years, how old would the sample be if 1/8 of the original isotope remained in the sample? F 20,000 years G 30,000 years H 40,000 years I 50,000 years Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 3. If a sample contains an isotope with a half-life of 5,000 years, how old would the sample be if 1/4 of the original isotope remained in the sample? A 10,000 years B 20,000 years C 30,000 years D 40,000 years Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 5. If a sample contains an isotope with a half-life of 5,000 years, how old would the sample be if 1/4 of the original isotope remained in the sample? A 10,000 years B 20,000 years C 30,000 years D 40,000 years Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. ESS 9.8.3 - 9.8.4 EXAM TEST 7 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Reading Read each of the passages. Then answer the questions that follow each passage. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Passage 1 Three hundred million years ago, the region that is now Illinois had a different climate than it does today. Swamps and shallow bays covered much of the area. No fewer than 500 species of plants and animals lived in this environment. Today, the remains of these organisms are found beautifully preserved within nodules. Continued on the next slide Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Passage 1, continued Nodules are round or oblong structures usually composed of cemented sediments that sometimes contain the fossilized hard parts of plants and animals. The Illinois nodules are exceptional because the soft parts of organisms are found together with hard parts. For this reason, these nodules are found in fossil collections around the world. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 1. In the passage, what is the meaning of the word exceptional? A beautiful B large C average D extraordinary Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 2. According to the passage, which of the following statements about nodules is correct? A Nodules are rarely round or oblong. B. Nodules are not found in present day Illinois. C Nodules are usually composed of cemented sediment. D Nodules always contain fossils. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 3. Which of the following is a fact in the passage? A. Both the hard and soft parts of organisms are preserved in the Illinois nodules. B Illinois has had the same climate throughout Earth’s history. C. The Illinois nodules are not well known outside of Illinois. D Fewer than 500 species of plants and animals have been found in Illinois nodules. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Passage 2 In 1995, paleontologist Paul Sereno and his team were working in an unexplored region of Morocco when they made an astounding find — an enormous dinosaur skull! The skull measured approximately 1.6 m in length, which is about the height of a refrigerator. Given the size of the skull, Sereno concluded that the skeleton of the animal it came from must have been about 14 m long — about as big as a school bus. Continued on the next slide Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Passage 2, continued The dinosaur was even larger than Tyrannosaurus rex! The newly discovered 90 million-year-old predator most likely chased other dinosaurs by running on large, powerful hind legs, and its bladelike teeth meant certain death for its prey. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 4. In the passage, what does the word astounding mean? A important B new C. one of a kind D. incredible Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 5. Which of the following is evidence that the dinosaur described in the passage was a predator? A. It had a large skeleton. B. It had bladelike teeth. C It was found with the bones of a smaller animal nearby. D It is 90 million years old. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 6. What types of information do you think that fossil teeth provide about an organism? A the color of its skin B. The speed that it ran C. the types of food it ate D the mating habits it had Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation Math Read each question and choose the best answer. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 7. Carbon-14 is a radioactive isotope with a half-life of 5,730 years. How old would a bone be that has gone through 3 half-lifes? A. 5,730 B 11,460 C 22,920 D 17,190 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 8. If a sample contains an isotope with a half-life of 5,000 years, how old would the sample be if 1/8 of the original isotope remained in the sample? A 20,000 years B 30,000 years C 15,000 years D 10,000 years Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 6 Standardized Test Preparation 9. If a sample contains an isotope with a half-life of 10,000 years, how old would the sample be if 1/4 of the original isotope remained in the sample? A 10,000 years B 20,000 years C 30,000 years D 40,000 years Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 1O. WHICH PRINCIPLE STATES “THE PRESENT IS THE KEY TO THE PAST”? • A. SUPERPOSITION B. UNIFORMPOSITION • C. UNIFORMITARIANISM D. SUPERUNIFORM • 11. THE SCIENCE OF THE STUDY OF PAST LIFE. • A. TOXOLOGY B. FOSSILOLOGY • C. DEADOLOGY D. PALEONTOLOGY • 12. THE PROCESS OF DETERMINING WHETHER AN EVENT OR OBJECT IS OLDER OR YOUNGER THAN OTHER EVENTS OR OBJECTS. • A. ABSOLUTE DATING B. RADIOMETRIC DATING • C. RADIOACTIVE DECAY D. RELATIVE DATING Chapter menu Resources • Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 13. THE PRINCIPLE THAT STATES THAT YOUNGER ROCKS LIE ABOVE OLDER ROCKS IF THE LAYERS HAVE NOT BEEN DISTURBED. • A. UNIFORMPOSITION B. UNIFORMITARIANISM • C. SUPERUNIFORM D. SUPERPOSITION • 14. A BREAK IN THE EARTH’S CRUST ALONG WHICH BLOCKS OF THE CRUST SLIDE RELATIVE TO ONE ANOTHER. • A. SPLIT B. JOINT C. FAULT D. CONFORMITY • 15. MOLTEN ROCKS FROM THE EARTH’S INTERIOR THAT SQUEEZES INTO EXISTING ROCKS AND COOLS. • A. INTRUSION B. FAULT C. EXTRUSION D. SPLIT Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 16. THIS OCCURS WHEN ROCK LAYERS BEND AND BUCKLE FROM EARTH’S INTERNAL FORCES. • A. FAULTING B. FOLDING C. PLATEAU D. TILTING • 17. THIS OCCURS WHEN INTERNAL FORCES IN THE EARTH SLANT ROCK LAYERS. • A. FAULTING B. PLATEAU C. TILTING D. FOLDING • 18. A BREAK IN THE ROCK RECORD. • A. CONFORMITY B. UNCONFORMITY C. TRILOBITE D. TILT Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 19. THESE EXIST WHERE PART OF A SEQUENCE OF PARALLEL ROCK LAYERS IS MISSING. • A. CONFORMITY B. FAULTING • C. JOINT D. DISCONFORMITY • 20. THESE EXIST WHERE SEDIMENTARY ROCK LAYERS LIE ON TOP OF AN ERODED SURFACE OF NON LAYERED IGNEOUS OR METAMORPHIC ROCK. • A. FAULTING B. JOINT • C. NONCONFORMITY D. COMFORMITY • Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 21. THESE EXISTS BETWEEN HORIZONTAL ROCK LAYERS AND ROCK LAYERS THAT ARE TILTED AND FOLDED. • A. ANGULAR UNCONFORMITY B. SQUARE CONFORMITY • C. DIAMOND UNCONFORMITY D. FAULT LINE • 22. ANY METHOD OF MEASURING THE AGE OF AN EVENT OR OBJECT BY ANALYZING ISOTOPES OF RADIOACTIVE ISOTOPES. • A. RELATIVE DATING B. ABSOLUTE DATING • C. ABSOLUTE RELATING D. RELATIVE AGE Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 23. ATOMS OF THE SAME ELEMENT THAT HAVE THE SAME NUMBER OF PROTONS BUT DIFFERENT NUMBERS OF NEUTRONS ARE CALLED _______. • A. ISOTOPES B. ELEMENTS C. RADONS D. ISOBAR • 24. AN UNSTABLE ISOTOPE IS SAID TO BE _________. • NEGATIVE B. RADIOACTIVE C. POSITIVE D. DEAD • 25. RADIOACTIVE DECAY OCCURS AT A _____ RATE. • A. STEADY B. FAST C. UNSTEADY D. SLOW Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 26. IN RADIOACTIVE DECAY, THE UNSTABLE RADIOACTIVE ISOTOPE IS CALLED THE ______ ISOTOPE. • A. DAUGHTER B. RELATIVE C. FATHER D. PARENT • 27. IN RADIOACTIVE DECAY, THE STABLE ISOTOPE IS CALLED THE _________ ISOTOPE. • A. RELATIVE B. DAUGHTER C. FATHER D. PARENT • 28. THE MORE ______ MATERIAL THERE IS, THE OLDER THE ROCK. • A. FATHER B. RELATIVE C. DAUGHTER D. PARENT Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 29. DETERMINING THE ABSOLUTE AGE OF A SAMPLE, BASED ON THE RATIO OF PARENT MATERIAL TO DAUGHTER MATERIAL IS CALLED ______________. • A. RADIOMETRIC RATING B. RADIOMETRIC DATING • C. RELATIVEMETRIC DATING D. ATOMMETRIC DATING • 30. THE TIME NEEDED FOR 1/2 OF A SAMPLE OF A RADIOACTIVE SUBSTANCE TO UNDERGO RADIOACTIVE DECAY. • A. NO LIFE B. FULL LIFE C. HALF LIFE D. HALF DEATH Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 31. TRACES OR REMAINS OF ORGANISMS THAT LIVED LONG AGO. • A. FOSTILS B. HALF LIFE C. MOLLUSKS D. FOSSILS • 32. ORGANISMS OCCASIONALLY BECAME TRAPPED IN SOFT STICKY TREE SAP THAT HARDENS AND BECOMES ______. • A. AMBER B. GUM C. ROCK D. TAR • 33. A PROCESS IN WHICH MINERALS REPLACE AN ORGANISMS TISSUE. • A. PUTRIFICATION B. PETRIFICATION • C. PURIFICATION D. ROCKATION Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 • 34. SINCE COLD TEMPERATURES SLOW DOWN DECAY, MANY TYPES OF FOSSILS HAVE BEEN FOUND PRESERVED IN ________. • A. ASPHALT B. LAVA C. MAGMA D. ICE • 35. NATURALLY PRESERVED EVIDENCE OF ANIMAL ACTIVITY. • A. INDEX FOSSIL B. TRACE FOSSILS • C. SPACE FOSSILS D. ACTIVE FOSSILS Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 FOSSIL IDENTIFICATION • • • • 36. A TRACE FOSSIL B. INSECTS IN AMBER C. MOLD D. CAST Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 FOSSIL IDENTIFICATION • • • • 37. A. INDEX FOSSIL B. PETRIFIED REMAINS C. FROZEN REMAINS D. TRACE FOSSILS Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 FOSSIL IDENTIFICATION • • • • 38 A. INDEX FOSSIL B. ORIGINAL REMAINS C. TRACE FOSSIL D. FROZEN REMAINS Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 FOSSIL IDENTIFICATION • • • • 39. A. INDEX FOSSIL B. MOLD/CAST C. PETRIFIED REMAINS D. FROZEN REMAINS Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved. TEST 7 FOSSIL IDENTIFICATION • • • • 40. A. TRACE FOSSIL B. PETRIFIED REMAINS C. INDEX FOSSIL D. AMBER Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.