Section 7. Reading the Geologic History of Your Community. What Do You See? Think About It. Investigate. Learning Outcomes

Size: px
Start display at page:

Transcription

2 Section 7 Reading the Geologic History of Your Community Part A: Basic Geologic Principles 1. Roll out three different colors of soft modeling clay: red, yellow, and blue. Place the red layer flat on the table. Place the yellow layer on top of it, followed by the blue layer. a) Which layer is the oldest (that is, has been there the longest)? Which layer is the youngest? 2. The geologic cross section in Figure A shows a series of layers of sedimentary units. As you read, sedimentary rocks are laid down in layers, much like the layers of clay in Step 1. a) Which of the units in the cross section do you think is the oldest? Which unit do you think is the youngest? How do you know? 3. Examine the clay layers from Step 1. a) Sketch a side view of what you see. b) Now form the layers into folds, as you did in the previous section. Sketch a side view of what you see now. c) Sedimentary and extrusive igneous rocks are originally laid down in nearly horizontal layers. Why do you think that the layers are not horizontal? Number the cross sections in Figure B in the order in which they would occur. 4. Flatten out the clay layers and again stack them into a block. Make a slanting cut through the block. Lift the lower side up relative to the upper side so that the red layer on the left matches up with the yellow layer on the right. Recall from Section 6 that you have produced a normal fault. a) Sketch what you see. b) Now, look at the two cross sections shown in Figure C. What is the youngest feature in each of the two cross sections? How do you know? 331

3 Chapter 3 Minerals, Rocks, and Structures 5. The geologic cross section shown in Figure D shows a sedimentary rock unit A and an intrusive igneous rock unit B. a) From what you know about how intrusive igneous rock units form, which of these units do you think is older? How do you know? Part B: Using the Principles to Interpret Geologic History 6. The rock units in the cross section shown in Figure E have been assigned approximate age ranges. a) Are the ages continuous, or do you see any time gaps? b) Assume that these are sedimentary rocks that were formed as sediment was slowly deposited, layer upon layer. Can you think of an explanation for why there is a time gap in the record? 1. The following cross section shows several rock units in an area that has had a long and varied geologic history. a) Put the rock units and other geologic features marked with letters in the cross section in order of occurrence from earliest to latest. Start by asking yourself what was there first, and then work your way forward through time. You can think of this as a geologic puzzle. A simplified cross section of strata. 332

4 Section 7 Reading the Geologic History of Your Community Digging Deeper INTERPRETING GEOLOGIC HISTORY Geologic Events and Processes In the Investigate, you studied how scientists determine the ages of rock layers. You did this by using models and cross sections. It is important for geologists to know the age of the rock layers. Most areas of Earth s crust have a long and often complex geologic history. Many kinds of geologic events can occur. Many kinds of geologic processes can shape the geologic history of an area. You have read about many of these in previous sections. Here are some important ones: deposition, erosion, folding, faulting, uplift, subsidence, igneous intrusion, volcanism, metamorphism, changes in sea level, and climate change. The only processes in the list above that you have not yet looked at in detail are uplift and subsidence. Local areas of Earth s crust can be slowly raised (uplift) by large-scale forces acting within Earth. They can also be lowered (subsidence). Vertical changes in elevation can range from meters to kilometers. Much of uplift and subsidence is caused by the movement of Earth s lithospheric plates. However, it can also be caused just by changes in the temperature of the rocks. When rocks cool, they contract. That causes subsidence. When rocks are heated, they expand. That causes uplift. The degree of contraction and expansion is small. However, great thicknesses of rock are affected (kilometers to tens of kilometers). As a result, uplift and subsidence of Earth s surface caused in this way can amount to hundreds of meters. Basic Geologic Principles Geologists make geologic maps of areas of bedrock. The surface geology shown in these maps comes from data gathered from a variety of sources. These include topographic maps, satellite images, and bore holes. Rocks in the field also provide data. A geologic map contains one or more cross sections. These are constructed by projecting the rock units and other geologic features seen at the surface downward into Earth. To do this, geologists must measure the angles that rock units and structures dip into Earth. The geologic map is a description of the bedrock. Geologists then use the map to interpret the area s geologic history. Figure 1 In a series of rock layers, the oldest rocks are usually found on the bottom while the youngest rocks are on the top. Geo Words uplift: the process by which local areas of Earth s crust can be slowly raised by largescale forces acting within Earth or the heating of rocks. subsidence: the process by which local areas of Earth s crust can be slowly lowered by large-scale forces acting within Earth or the cooling of rocks. 333

5 Chapter 3 Minerals, Rocks, and Structures Geo Words stratigraphy: the scientific study of rock layers (called strata). The scientific study of rock layers is called stratigraphy. This involves the application of several basic principles, which follow. Some of these principles might seem like common sense to you. In a way, they are. However, when they were first developed long ago, they were revolutionary. They advanced how early geologists thought about the geologic record. They provide powerful tools for analyzing the relative ages of rock layers and structures. Principle of Superposition: Younger sedimentary and volcanic rocks are deposited on top of older rocks, as shown in Figure 1 on the previous page. Principle of Original Horizontality: Sedimentary and volcanic rocks are laid down in nearly horizontal layers. Principle of Lateral Continuity: Sedimentary and volcanic rocks are laid down in layers that are usually much greater in lateral extent than in thickness. Principle of Crosscutting Relationships: If one rock unit or geologic feature cuts across another rock unit or geologic feature, it was formed later in geologic time. Here are two examples of this principle. If you see a rock unit cut by an igneous intrusion, such as a dike, you can be sure that the dike is younger than the rock unit. (See Figure 2.) If you see one or more rock units cut by a fault, then you know that the fault is younger than the rock units. (See Figure 3.) Figure 2 Which rock unit shown in the photograph is the youngest? Figure 3 After intruding into the surrounding granite, this dike was offset by a fault. 334

6 Section 7 Reading the Geologic History of Your Community Unconformities There is another important concept to think about when trying to interpret the geologic history of an area. Successions of sedimentary and volcanic rocks are deposited on an earlier rock surface. The contact between that earlier rock and the younger layers is called an unconformity. It is important to note that for some period time, nothing except perhaps erosion was occurring on this surface. Some period of geologic time was not recorded at the surface. The missing time might be as short as thousands of years. However, it is usually much longer. It can be hundreds of thousands to many millions of years long. At some unconformities, more than a billion years of Earth history is not recorded. Figures 4a b show two common kinds of unconformity. In Figure 4a, younger sedimentary rock is resting on an older one. The older one was folded. Then it eroded down. This occurred before conditions changed and more sediment was deposited. In Figure 4b, a younger sedimentary succession is resting on an intrusive body of granite. The granite was placed deep in Earth. Erosion later wore down the land surface to the level of the granite intrusion. Then conditions changed for some reason. Sediment was deposited on the previously eroded surface. These examples show that an unconformity can be very helpful in interpreting geologic history. Figure 4a An unconformity in which the older, underlying rocks are at a different angle than the younger, overlying rocks is called an angular unconformity. Figure 4b An unconformity developed when older igneous rocks were exposed to erosion before sedimentary rocks covered them is called a nonconformity. Geo Words succession: a number of rock units or a mass of strata that succeed one another in chronological order; the chronological order of rock units. unconformity: the contact between an earlier rock and younger sedimentary and/or volcanic layers. 335

7 Chapter 3 Minerals, Rocks, and Structures The Use of Fossils in Dating Geologic Successions Geo Words principle of faunal succession: the kinds of animals and plants found as fossils change through time. When the same kinds of fossils in rocks are found from different places, the rocks are the same age. As you have read, fossils represent the remains of once-living organisms. Most fossils are the remains of organisms that are extinct. This means that they are no longer living anywhere on Earth. Fossil records help to mark the divisions within the geologic time scale. These divisions are largely based on the appearance and disappearance of specific species of fossils. Scientists use fossils to find information about the ages of rocks. To help them do this, they have developed the principle of faunal succession. This states that because life on Earth has changed through time, the kinds of fossils found in rocks of different ages will also differ. This means that when the same kinds of fossils are found in rocks from different places, then those rocks are the same age. Therefore, if the age range of fossils contained in a rock are known then the age of that rock can be determined. Figure 5 Species of mollusks used as index fossils to identify specific periods of geologic time. 336

8 Section 7 Reading the Geologic History of Your Community Fossils that lived for narrow time spans are very important. They can be used to indicate very specific periods in geologic time. These are known as index fossils. Examples of index fossils are shown in Figure 5. The presence of a key index fossil in a rock reveals the date of the rock. For example, the trilobite Paradoxides pinus indicates that a rock was deposited between the Ordovician and Cambrian Periods. Most often, rocks contain several fossils without an index fossil. In that case, scientists look at the overlap in the age ranges of the fossils. They try to find the period when all the fossils existed at the same time. In this way, they are able to narrow down the ages of these rocks. This approach to finding the relative ages of rocks is called biostratigraphy. Figure 6 shows the history of five fossils. It illustrates how biostratigraphy is used to determine the age ranges of three fossil-bearing rocks. Geo Words index fossil: a fossil with narrow age range and a wide distribution that can be used to date rocks. biostratigraphy: the study of and differentiation of rock units based on the fossils they contain. Figure 6 A hypothetical example of the age ranges of five fossils. The ranges are: Fossil A is Silurian to Ordovician; Fossil B is Cretaceous to Devonian; Fossil C is Quaternary to Ordovician; Fossil D is Jurassic to Silurian; and Fossil E is Tertiary to Jurassic. The age ranges of the rocks are: Rock A is Silurian to Ordovician; Rock B is Cretaceous to Jurassic; and Rock C is Jurassic to Devonian. Species that make good index fossils have the following characteristics: well preserved so they are easy to find distinctive body shapes that make them easy to recognize large populations so they are abundant a widespread distribution that allows for distant locations to be compared existing for relatively short periods of time that indicate precise ages 337

9 Chapter 3 Minerals, Rocks, and Structures Index fossils are often from animal species that had hard, exterior bodies. Also, the best index fossils are from animals that lived mainly on or near the seafloor. The water would also need to be quite calm. For these reasons, the most common index fossils are marine mollusks. Figure 5 shows many of the different kinds of mollusks used to identify the ages of rock layers. For example, in sedimentary rocks from the Jurassic and Triassic Periods, the flat spiraled shells of ammonites are common. They evolved very rapidly. They could also be found throughout the oceans during these periods. As a result, they are very useful for comparing the ages of rocks on all the continents. Earlier than the Paleozoic Era, the trilobites achieved similar success. They are an index fossil for sedimentary layers dating back to 520 million years. Fossils can be used to find the relative age of the rock layers in which they occur. Then the age can be correlated to other sequences containing similar layers. Following this approach, a longer sequence can be constructed from many smaller sequences. Look at Figure 7. The oldest rocks in Outcrop B appear at its base. The mollusks they contain are the same age as those at the top of Outcrop A. Therefore, the lower layers in Outcrop A may provide insight into the geologic history below the oldest layer of Outcrop B. On the other hand, Outcrop C can be correlated to the top of Outcrop B. It reveals a younger part of the stratigraphic column. Figure 7 Biostratigraphic correlation of rock layers from different places using the ages of fossils found within the layers. 338

10 Section 7 Reading the Geologic History of Your Community There are a number of different reasons scientists want to know the age of rocks. For instance, this information is used to predict the locations of coal and minerals. It is also used to reconstruct the geologic history of an area. For example, scientists have correlated rock layers in Chesapeake Bay on the mid-atlantic coast. This has helped them determine how this bay was formed. They determined that 35 million years ago a meteorite hit the area. (See Figure 8.) It created a massive impact crater. They found that before the impact, sedimentary Figure 8 The meteorite impact site that formed the Chesapeake Bay. layers extended laterally for long distances. After the impact, these sedimentary layers were disrupted. (See Figure 9.) They were disrupted by several faults along the rim of the crater. Using index fossils, they observed that along these faults, younger layers were moved against older layers in the sequence. The main impact structure is now buried beneath sediments in the bay. Figure 9 Faults along the rim of the crater disrupted the sedimentary beds. The original stratigraphic sequence was reconstructed using fossils. Checking Up 1. What causes uplift and subsidence? 2. How do unconformities form? 3. Define and explain two of the major principles used by geologists to interpret the rock record. 4. What is an index fossil? 339

12 Section 7 Reading the Geologic History of Your Community Inquiring Further 1. Dating techniques In this section, you have read about how to tell the relative age of rocks from their relationships to each other. Geologists also use other techniques to determine the ages of rocks. Research radiometric dating and describe how it is used and how it differs from the techniques that you learned in this section. Be sure to cite the sources you used in your research and discuss how you evaluated their reliability. 341

Section 5. Rock Units and Your Community. What Do You See? Think About It. Investigate. Learning Outcomes

Chapter 3 Minerals, Rocks, and Structures Section 5 Rock Units and Your Community What Do You See? Learning Outcomes In this section, you will Recognize that rocks are arranged in Earth s crust as well-defined

Directed Reading A. Section: Relative Dating: Which Came First?

Skills Worksheet Directed Reading A Section: Relative Dating: Which Came First? Write the letter of the correct answer in the space provided. 1. Determining the age of objects or events in relation to

Skills Worksheet Directed Reading page 185-190 Section: Determining Relative Age 1. How old is Earth estimated to be? 2. Who originated the idea that Earth is billions of years old? 3. On what did the

ENVI.2030L Geologic Time

Name ENVI.2030L Geologic Time I. Introduction There are two types of geologic time, relative and absolute. In the case of relative time geologic events are arranged in their order of occurrence. No attempt

Earth s Changing Surface Chapter 4

Name Hour Due Date Earth s Changing Surface Chapter (You do not need your book) Page 1 Fossils Summary Page 2 Traces of Tracks Page 3 Finding the Relative Age of Rocks Summary. Page - Finding the Relative

Unit 6: Interpreting Earth s History

Unit 6: Interpreting Earth s History How do we know that the Earth has changed over time? Regent s Earth Science Name: Topics Relative Dating Uniformitarianism Superposition Original Horizontality Igneous

UNCONFORMITY. Commonly four types of unconformities are distinguished by geologists: a) Disconformity (Parallel Unconformity)

UNCONFORMITY Unconformities are gaps in the geologic record that may indicate episodes of crustal deformation, erosion, and sea level variations. They are a feature of stratified rocks, and are therefore

Station Look at the fossil labeled # 16. Identify each of the following: a. Kingdom b. Phylum c. Class d. Genus

Station 1 1. Look at the fossil labeled # 16. Identify each of the following: a. Kingdom b. Phylum c. Class d. Genus 2. Look at the fossil labeled #7. Identify each of the following: a. Kingdom b. Phylum

Age of Earth/Geologic Time. Vocabulary

Age of Earth/Geologic Time Vocabulary Big Ideas Geologic Time Earth Structures Identify current methods for measuring the age of Earth and its parts, including the law of superposition and radioactive

Law of Superposition Law of Superposition

History of Earth Relative Dating In the same way that a history book shows an order of events, layers of rock (called strata) show the sequence of events that took place in the past. Using a few basic

State the principle of uniformitarianism. Explain how the law of superposition can be used to determine the relative age of rocks.

Objectives State the principle of uniformitarianism. Explain how the law of superposition can be used to determine the relative age of rocks. Compare three types of unconformities. Apply the law of crosscutting

PLEASE DO NOT WRITE ON THIS QUIZ! Relative Dating and Stratigraphic Principles Quiz

PLEASE DO NOT WRITE ON THIS QUIZ! Relative Dating and Stratigraphic Principles Quiz TEST NO A Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.

Earth s History. The principle of states that geologic processes that happened in the past can be explained by current geologic processes.

Earth s History Date: Been There, Done That What is the principle of uniformitarianism? The principle of states that geologic processes that happened in the past can be explained by current geologic processes.

Rock cycle diagram. Principle of Original Horizontality. Sediment is deposited horizontally

Geologic Time Rock cycle diagram Leaves of History Chapter 21 Lateral Continuity Principle of Original Horizontality Sediment is deposited horizontally Principle of Superposition Oldest rock A Younger

Deep Time: How Old Is Old?

Deep Time: How Old Is Old? Updated by: Rick Oches, Professor of Geology & Environmental Sciences Bentley University Waltham, Massachusetts Based on slides prepared by: Ronald L. Parker, Senior Geologist

Fossils: evidence of past life

Fossils: evidence of past life Remains or traces of prehistoric life Petrified Cavities and pores are filled with precipitated mineral matter Petrified Formed by replacement Cell material is removed and

Rock cycle diagram. Relative dating. Placing rocks and events in proper sequence of formation Deciphering Earth s history from clues in the rocks

Geologic Time Rock cycle diagram Leaves of History Chapter 21 Modern geology Uniformitarianism Fundamental principle of geology "The present is the key to the past Relative dating Placing rocks and events

Principle of Uniformitarianism: Laws of nature don t change with time

G e o l o g i c T i m e Principle of Uniformitarianism: Laws of nature don t change with time Radical idea proposed by Hutton in 1780 s Proposed that past events could be explained by modern processes

CHAPTER 8 DETERMINING EARTH S AGE RELATIVE AND ABSOLUTE ROCK AGES. Loulousis

CHAPTER 8 DETERMINING EARTH S AGE RELATIVE AND ABSOLUTE ROCK AGES Loulousis Bellringer What are 5 visual clues that help you determine if someone is older or younger than you? Color of hair Wrinkles in

Objectives. Vocabulary. Describe the geologic time scale. Distinguish among the following geologic time scale divisions: eon, era, period, and epoch.

The Geologic Time Scale Objectives Describe the geologic time scale. Distinguish among the following geologic time scale divisions: eon, era, period, and epoch. Vocabulary geologic time scale eon era period

Remains or traces of prehistoric life

Fossils: evidence of past life Remains or traces of prehistoric life Petrified Cavities and pores are filled with precipitated p mineral matter Petrified Formed by replacement Cell material is removed

Earth Science 11: Geologic Time Unit

Earth Science 11: Geologic Time Unit Text: Chapters 8 Lab: Exercise 6 Name Earth Science 11: Geologic Time Page 1 Geology 12: Geologic Time 8.1: The Geologic Time Scale Today, we know that Earth is approximately

Geological Time How old is the Earth

Geological Time How old is the Earth How old is everything? Universe? Universe ~ 14 Billion Years Old Milky Way Galaxy? Milky Way Galaxy - 10 Billion Years Old Solar System? Solar System -4.6 Billion Years

Absolute Time. Part 8 Geochronology and the Time Scale

Absolute Time Part 8 Geochronology and the Time Scale Unless otherwise noted the artwork and photographs in this slide show are original and by Burt Carter. Permission is granted to use them for non-commercial,

Geologic Time. Decoding the Age of our Planet & North Carolina

Geologic Time Decoding the Age of our Planet & North Carolina The Geologic Time Scale Objectives Describe the geologic time scale. Distinguish among the following geologic time scale divisions: eon, era,

Geologic Time. Geologic Events

Geologic Time Much of geology is focused on understanding Earth's history. The physical characteristics of rocks and minerals offer clues to the processes and conditions on and within Earth in the past.

9. DATING OF ROCKS, FOSSILS, AND GEOLOGIC EVENTS

LAST NAME (IN CAPS): FIRST NAME: Instructions: 9. DATING OF ROCKS, FOSSILS, AND GEOLOGIC EVENTS Refer to Laboratory 8 in your Lab Manual on pages 207-226 to answer the questions in this work sheet. Your

Answers to Section G: Time and the Fossil Record (Relative Dating)

Answers to Section G: Time and the Fossil Record (Relative Dating) Use the following sketch of a geological cross section to answer questions 1 to 3. 1. The most important principle used to determine the

Name Geo 4 Practice Match the principle on the left (column A) with the definition (or part of the definition) on the right (column B).

Name Geo 4 Practice 1 Target 1 2 3 4 Geo 4 I can define the create, alter and/or destroy the rock record. I can interpret a diagram to determine the sequence of events (relative age) in Earth s history

L.O: HOW GEOLOGISTS SEQUENCE EVENTS IN EARTH'S GEOLOGIC HISTORY IF NOT OVERTURNED, OLDEST ON BOTTOM, YOUNGEST ON TOP

L.O: HOW GEOLOGISTS SEQUENCE EVENTS IN EARTH'S GEOLOGIC HISTORY IF NOT OVERTURNED, OLDEST ON BOTTOM, YOUNGEST ON TOP 1. Unless a series of sedimentary rock layers has been overturned, the bottom rock layer

6. Relative and Absolute Dating

6. Relative and Absolute Dating Adapted by Sean W. Lacey & Joyce M. McBeth (2018) University of Saskatchewan from Deline B, Harris R, & Tefend K. (2015) "Laboratory Manual for Introductory Geology". First

LAST NAME (IN CAPS): FIRST NAME: Instructions: 9. RELATIVE AND RADIOMETRIC AGES Your work will be graded on the basis of its accuracy, completion, clarity, neatness, legibility, and correct spelling of

Unit 5: Earth s History Practice Problems

Name: Date: 1. Which bedrock would be most likely to contain fossils? A. Precambrian granite B. Cambrian shale C. Pleistocene basalt D. Middle-Proterozoic quartzite 6. Base your answer(s) to the following

geologic age of Earth - about 4.6 billion years

Geologic Time Geologic Time geologic age of Earth - about 4.6 billion years Geologic Time very difficult to appreciate from our human perspective necessary to understand history of Earth two basic ways

GEOLOGIC TIME AND GEOLOGIC MAPS

NAME GEOLOGIC TIME AND GEOLOGIC MAPS I. Introduction There are two types of geologic time, relative and absolute. In the case of relative time geologic events are arranged in their order of occurrence.

Structural Geology Lab. The Objectives are to gain experience

Geology 2 Structural Geology Lab The Objectives are to gain experience 1. Drawing cross sections from information given on geologic maps. 2. Recognizing folds and naming their parts on stereoscopic air

Warm Up Name the 5 different types of fossils

Warm Up Name the 5 different types of fossils Timeline that organizes the events in Earths history. Earth is about 4.7 billion years old. More complex organism such as land plants and fish evolved only

SAMPLE QUESTIONS FOR GEOLOGY 103, TEST 1

SAMPLE QUESTIONS FOR GEOLOGY 103, TEST 1 The correct answers are listed at the bottom (no peeking!). These questions are to give you an idea of the type of questions that will be asked. They are not a

Fossils. Name Date Class. A Trip Through Geologic Time Section Summary

Name Date Class A Trip Through Geologic Time Section Summary Fossils Guide for Reading How do fossils form? What are the different kinds of fossils? What does the fossil record tell about organisms and

Exploring Geology Chapter 9 Geologic Time

Exploring Geology Chapter 9 Geologic Time Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 9: Geologic Time Stratigraphic Principles Relative Age Dating

Lab 4: Structures and Geologic Maps

Key Questions: GEOL 1311 Earth Science Lab 4 Structures and Geologic Maps What shapes do rock bodies take in the Earth? How do two-dimensional visualizations of the Earth, such as maps and cross-sections

A Trip Through Geologic Time

A Trip Through Geologic Time A Trip Through Geologic Time Review In: Have the same animals that live today always been on Earth? Illustrate and JUSTIFY. When finished with this In Question, show Ms. Johnson

The Geology of Pacific Northwest Rocks & Minerals Activity 1: Geologic Time

Name: Age: I. Introduction There are two types of geologic time, relative and absolute. In the case of relative time geologic events are arranged in their order of occurrence. No attempt is made to determine

GEOLOGY GL1 Foundation Unit

Candidate Name Centre Number Candidate Number 2 General Certificate of Education Advanced Subsidiary/Advanced 451/01 GEOLOGY GL1 Foundation Unit P.M. THURSDAY, 10 January 2008 (1 hour) Examiner Question

Timeline that organizes the events in Earths history. Earth is about 4.7 billion years old. More complex organism such as land plants and fish

Timeline that organizes the events in Earths history. Earth is about 4.7 billion years old. More complex organism such as land plants and fish evolved only with in the last 500 million years. Humans evolved

Before the 1700 s, scientists thought that the Earth was only 6,000 years old. This mindset was based on biblical references.

Before the 1700 s, scientists thought that the Earth was only 6,000 years old. This mindset was based on biblical references. However, as scientists began to better understand the processes that shape

Relative Dating. The Rock Cycle. Key Concept Scientists can interpret the sequence of events in Earth s history by studying rock layers.

2 What You Will Learn The rock cycle includes the formation and recycling of rock. Relative dating establishes the order in which rocks formed or events took place. The principle of superposition states

GEOLOGIC EVENTS SEDIMENTARY ROCKS FAULTING FOLDING TILTING

RELATIVE TIME (DATING) ABSOLUTE TIME (DATING) GEOLOGIC TIME List the order in which events occurred, without regard to the amount of time separating them. Refers to the age of a rock in relation to other

II. Knowing and Understanding the Six Principles of Stratigraphy:

Student Name(s): Physical Geology 101 Laboratory Relative Dating of Rocks Using Stratigraphic Principles Grade: I. Introduction & Purpose: The purpose of this lab is to learn and apply the concepts of

Clues to Earth s Past. Fossils and Geologic Time

Clues to Earth s Past Fossils and Geologic Time Fossils A. Paleontologists study fossils and reconstruct the appearance of animals. Fossils B. Fossils remains, imprints, or traces of prehistoric organisms

Lecture Outline Friday Feb. 21 Wednesday Feb. 28, 2018

Lecture Outline Friday Feb. 21 Wednesday Feb. 28, 2018 Questions? Key Points for today What are the 5 relative age dating principles and how do you apply the principles to determine a geologic history

Prentice Hall EARTH SCIENCE

Prentice Hall EARTH SCIENCE Tarbuck Lutgens Chapter 12 Geologic Time 12.1 Discovering Earth s History Rocks Record Earth History Rocks record geological events and changing life forms of the past. We have

5. Compare the density of the oceanic crust to continental crust. 6. What kind of plate boundary is this? convergent

The youngest rock is in the middle (at ridge) and it gets older on either side as you move away in a symmetrical pattern. 1. How does the age of the seafloor compare on either side of the ridge? A = youngest

HISTORICAL GEOLOGY. Relative & Absolute age, fossils and geologic time

HISTORICAL GEOLOGY Relative & Absolute age, fossils and geologic time Historical Geology A. Measuring Time 1. Relative Time (Relative Age) Measurement of time using comparison. No numbers used; uses words

GEOLOGICAL TIME / DATING TECHNIQUES

DATE DUE: INSTRUCTOR: TERRY J. BOROUGHS Geology 305 NAME: SECTION: GEOLOGICAL TIME / DATING TECHNIQUES Instructions: Read each question carefully before selecting the BEST answer. Provide specific and

Before the 1700 s, scientists thought that the Earth was only 6,000 years old. This mindset was based on biblical references.

Before the 1700 s, scientists thought that the Earth was only 6,000 years old. This mindset was based on biblical references. However, as scientists began to better understand the processes that shape

Earth History Exam. The remains of an early dinosaur could be found at reference point A. A B. B C. C D. D. page 1

Name: Date: 1. Base your answer(s) to the following question(s) on the Earth Science Reference Tables and your knowledge of Earth science. The accompanying cross section shows undisturbed sedimentary bedrock.

Chapter 09 Geologic Time

Physical Geology 1330 116-S&R 1 Chapter 09 Geologic Time Lectures 12 & 13 Dr. Mike Murphy mmurphy@mail.uh.edu 333-S&R-1 www.uh.edu/~mamurph2/homepage.html Two Ways to Date Geologic Events 1. Relative Dating

Principles of Geology

Principles of Geology Essential Questions What is Uniformitarianism? What is Catastrophism? What is Steno s s Law? What are the other geologic principles? How is relative age determined using these principles?

8. GEOLOGIC TIME LAST NAME (ALL IN CAPS): FIRST NAME: Instructions

LAST NAME (ALL IN CAPS): FIRST NAME: Instructions 8. GEOLOGIC TIME Refer to Exercise 6 in your Lab Manual on pages 151-168 to answer the questions in this work sheet. Your work will be graded on the basis

Name Test Date Hour. forms that lived only during certain periods. abundant and widespread geographically. changes to the surface of Earth.

Name Test Date Hour Earth Processes#3 - Notebook Earth s History LEARNING TARGETS I can explain the lack of evidence about the Precambrian Time. I can describe possible causes for the mass extinction in

Name Date EARTH S HISTORY VOCABULARY

Name Date EARTH S HISTORY VOCABULARY Use Figure 2 to answer the following two questions. 10. Interpreting Graphics Which is older the sandstone layer or Dike A? Explain your answer. Conglomerate Sandstone

Fossils & The Geologic Time Scale

Fossils & The Geologic Time Scale Fossils Preserved remains or traces of an organism that lived in the past. Fossils are formed when organisms die and are buried in sediment. Eventually the sediment builds

Today you will be able to: Utilize the SEVEN rules of rock age identification to describe the geologic age of this rock sequence!

Mr. Sandomenico Welcome!!!! Today we will begin a new unit! The Earth s History!!!!! Today you will be able to: Utilize the SEVEN rules of rock age identification to describe the geologic age of this rock

Geologic Time: Hutton s Outcrop at Siccar Point. How do we determine age (relative & absolute) What is the age of the earth? How do we know?

Geologic Time: How do we determine age (relative & absolute) What is the age of the earth? How do we know? What is the age of the Earth? A. 4.44 million years B. 1 million years C. 4.55 billion years D.

Determining geological ages

Determining geological ages Relative ages placing rocks and geologic events in their proper sequence, oldest to youngest. Absolute dates define the actual numerical age of a particular geologic event.

GO ON. Directions: Use the diagram below to answer question 1.

d i a g n o s t i c t e s t : e a r t h a n d s p a c e s c i e n c e question 1. 1. What is the correct order (starting from the surface) of Earth s layers? A crust, outer core, inner core, mantle B mantle,

3. Bedrock from which entire geologic time period is missing between rock units 5 and 6? The fault most likely occurred after

Homework # 4 Relative Dating Name: Section: Date: 1. The cross section below represents a portion of Earth s crust. Letters through D are locations within the rock units. 5. The sequence of rock types

GEOLOGIC TIME. Smith and Pun, Chapter 7 DETERMINING THE ORDER OF EVENTS

GEOLOGIC TIME Smith and Pun, Chapter 7 DETERMINING THE ORDER OF EVENTS Examination of ancient rocks reveals the history of our planet. Sedimentary and volcanic rocks record processes that occur on the

Geohistory Review. Things you need to know:

Geohistory Review Things you need to know: a) The earth and the solar system are 4.5 billion years old (4.5 X 10 9 ) b) Law of original horizontality: Sedimentary rock layers are always deposited as horizontal

Geologic Time Test Study Guide

Geologic Time Test Study Guide Chapter 12 Section 1 The Earth s Story and Those Who First Listened 1. What is the difference between uniformitarianism and catastrophism? Uniformitarianism: the same geologic

Notepack 18 AiM: How can we tell the age of rock layers? Do now: Which Jenga piece was placed first to build this tower? Support your answer with

Notepack 18 AiM: How can we tell the age of rock layers? Do now: Which Jenga piece was placed first to build this tower? Support your answer with complete sentences. How old is the Earth? The Earth is

1. The timeline below represents time on Earth from the beginning of the Paleozoic Era Ato the present B.

Name Roy G Biv 1. The timeline below represents time on Earth from the beginning of the Paleozoic Era Ato the present B. Which numbered position best represents the time when humans first appeared in the

Lecture 10 Constructing the geological timescale

Lecture 10 Constructing the geological timescale Geologic Time Discovering the magnitude of the Earth s past was a momentous development in the history of humanity This discovery forever altered our perception

Relative Dating. How do we determine a rocks age by the surrounding rocks?

Relative Dating How do we determine a rocks age by the surrounding rocks? 1 Geologic History 2 Relative Dating Uniformitarianism - the idea that forces working on our planet today worked on our planet

Dating the age of the Earth

Dating the age of the Earth What is the age of the Earth? A. 4.44 million years B. 1 million years C. 4.55 billion years D. 10000 years Discuss this with your neighbor: How do we know the age of the Earth?

Geologic Time: Concepts and Principles

Geologic Time: Concepts and Principles Introduction - An appreciation for the immensity of geologic time is essential for understanding the history of our planet - Geologists use two references for time

Geologic and Rock Cycles, Fossils and Unconformities

Geologic and Rock Cycles, Fossils and Unconformities The Geologic Cycle 3 key events: deposition, uplift, erosion Sedimentation of beds A-D beneath the sea Uplift above sea level and exposure of D to erosion

A Trip Through Geologic Time

Date Class _ A Trip Through Geologic Time Chapter Test A Multiple Choice Write the letter of the correct answer on the line at the left. 1. Late in the Paleozoic Era, the supercontinent Pangaea formed.

THE HISTORY OF THE EARTH EARTH SCIENCE

THE HISTORY OF THE EARTH EARTH SCIENCE FOSSILS Paleontology is the study of life that existed in prehistoric times A fossil is any evidence of earlier life preserved in rock. Shells Bones Petrified trees

Geologic Time Essentials of Geology, 11th edition, Chapter 18 Geologic Time: summary in haiku form Key Concepts Determining geological ages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Geologic Time Essentials of Geology, 11 th edition, Chapter 18 Geologic Time: summary in haiku form Superposition and horizontality tell stories in rocks. Key

Geology of the Hawaiian Islands

Geology of the Hawaiian Islands Class 12 19 February 2004 A B C D F 97 94 92 91 88 87 86 85 85 84 82 77 73 73 mean 66 64 60 69 60 57 51 29 Exam Scores Mean = 71 Median = 82/77 Any Questions? Sedimentary

Name: Date: Class: This is a printable assignment.

Name: Date: Class: Tell the Story of Rock Sequences Earth Science Exercise Parts 1 and 2: Look at the illustrations below which show several horizontally layered sedimentary rock layers, unconsolidated

GEOLOGIC HISTORY DIAGRAMS

NAME: Log onto YouTube and search for jocrisci channel. GEOLOGIC HISTORY DIAGRAMS (Video 6.1) 1. Given a geologic cross section, you must be able to recognize folding, faulting, intrusions, unconformities,

Stratigraphy. Stratigraphy deals with the study of any layered (stratified) rock, but primarily with sedimentary rocks and their

Stratigraphy Stratigraphy deals with the study of any layered (stratified) rock, but primarily with sedimentary rocks and their composition origin age relationships geographic extent Stratified Sedimentary

Clues to Earth s Past

chapter 13 3 Clues to Earth s Past section 2 Relative Ages of Rocks Before You Read Think of two friends. You want to know who is older. What information do you need to figure out who s older? What You

A) B) C) D) 4. Which diagram below best represents the pattern of magnetic orientation in the seafloor on the west (left) side of the ocean ridge?

1. Crustal formation, which may cause the widening of an ocean, is most likely occurring at the boundary between the A) African Plate and the Eurasian Plate B) Pacific Plate and the Philippine Plate C)

GEOLOGICAL TIME / DATING TECHNIQUES

DATE DUE: INSTRUCTOR: TERRY J. BOROUGHS Geology 305 NAME: SECTION: GEOLOGICAL TIME / DATING TECHNIQUES Instructions: Read each question carefully before selecting the BEST answer. Provide specific and

GEOLOGY 1--Physical Geology Lecture #2, 2/9/2006

Topics: GEOLOGY 1--Physical Geology Lecture #2, 2/9/2006 Lithospheric plates and their motions Types of plate boundaries or margins The present is the key to the past Relative Time Numerical Age Age of

FOSSILS. Book G Chapter 4 Section 1

FOSSILS Book G Chapter 4 Section 1 OVERVIEW Explain what fossils are and how most fossils form. Describe what fossils tell about how organisms have changed over time. Identify and describe different types

Earth Science. Name Block. Unit 3 Review Worksheet. Circle the letter that corresponds to the correct answer

Earth Science Unit 3 Review Worksheet Name Block Circle the letter that corresponds to the correct answer 1. Which geologic principle is used when a geologist observes an outcrop or rocks and determines

THE CONTACT BETWEEN THE PRECAMBRIAN SHIELD AND THE PHANEROZOIC SEDIMENTARY ROCKS Lab Report (Lab #2) Submitted to: Professor Simone Dumas

THE CONTACT BETWEEN THE PRECAMBRIAN SHIELD AND THE PHANEROZOIC SEDIMENTARY ROCKS Lab Report (Lab #2) Submitted to: Professor Simone Dumas For the course Introduction to Earth Materials (GE01115) By: Gabriella

GLY 155 Introduction to Physical Geology, W. Altermann. Press & Siever, compressive forces. Compressive forces cause folding and faulting.

Press & Siever, 1995 compressive forces Compressive forces cause folding and faulting. faults 1 Uplift is followed by erosion, which creates new horizontal surface. lava flows Volcanic eruptions cover

Earth History. What is the Earth s time scale? Geological time Scale. Pre-Cambrian. FOUR Eras

The Earth is 4.6 billion years old! Earth History Mrs. Burkey ESS Cy Creek HS 17-18 If the Earth formed at midnight 6:00 am First life appears 10:00 pm First animals/plants on land 11:59 pm First humans

Objectives: Define Relative Age, Absolute Age

S6E5. Students will investigate the scientific view of how the earth s surface is formed. c. Classify rocks by their process of formation. g. Describe how fossils show evidence of the changing surface

Structural Geology Lab. The Objectives are to gain experience

Geology 2 Structural Geology Lab The Objectives are to gain experience 1. Drawing cross sections from information given on geologic maps. 2. Recognizing folds and naming their parts on stereoscopic air

Deep Time: How Old Is Old?

Deep Time: How Old Is Old? Updated by: Based on slides prepared by: Rick Oches, Professor of Geology & Environmental Sciences Bentley University Waltham, Massachusetts Ronald L. Parker, Senior Geologist