Interpreting Earth’s Rocks to Determine Its Past History.

Slides:

Advertisements

Similar presentations

CHAPTER 9: Clues to Earth’s past

Advertisements

Age Dating of Rocks.

Relative Dating : Which Came First?

Geologic Time, Unconformities and Relative Dating Uniformitarianism Appendix A.

Sci. 3-2 Relative Dating: Which Came First?

Use answer key to make correction to p. 2 in binder

Relative Dating and Sequencing Relative vs. Absolute Time Laws Unconformities Correlating Geologic Cross Sections.

RELATIVE TIME: When the age of rock is compared to the ages of other rocks or events in geological time. Can determine which layers are older than others.

Unit 5: Age of the Earth Objective:

 Uniformitarianism- Principle that states that the same geological process shaping the Earth today have been at work throughout Earth’s history.  Examples:

Earth’s History.

1 Lab 08 ONLINE LESSON. 2 If viewing this lesson in Powerpoint Use down or up arrows to navigate.

GEOLOGIC PRINCIPLES & RELATIVE DATING. HOW OLD IS THE EARTH? The Earth is about 4.6 billion years old Much of its history is recorded in the rocks Observations.

Key Ideas State the principle of uniformitarianism.

Beginning with a History of Geology. 1. Catastrophism 1. Earth was shaped by dramatic events called catastrophes 2. Like MASSIVE earthquakes, floods,

WELCOME TO CLASS. Agenda TODAY Sequencing Time Rock Record Notes Relative Age activity Hand back tests NEXT TIME Absolute age lab Geologic Time QUIZ.

Discovering Earth’s History Rocks Record Earth’s History 1. Rocks record geological events and changing life forms of the past. 2.Scientists have learned.

Determining geological ages

Geology Review Game Ready your Mind!. Your teams are your table groups.

Interpreting Earth’s Rocks to Determine Its Past History.

QUIZ 1.According to the scientific community how old is the Earth? 2.What type of rock are the oldest know rocks? 3.What are Time units largely based.

Dating Rocks Ways to tell the age of a rock. What are relative and absolute Locations?

Determining Relative Age The beginning of modern geology.

Relative Dating and Relative Age

We know Earth is 4.6 Billion years old

21.2 – Relative Age Dating How can you tell if one rock layer is older than another? How can you tell if one fossil is older than another? What is an index.

The Rock Record Section 1 Section 1: Determining Relative Age Preview Objectives Uniformitarianism Relative Age Law of Superposition Principle of Original.

Ch. 13 Section 2 Relative Ages of Rocks.

James Hutton proposed the principle of uniformitarianism. This states that the processes occurring on Earth today, have been occurring since Earth first.

Determining geological ages

Jump to first page Geologic Time Chapter 34. Jump to first page Dating rocks n Relative dating F Compare events and put them in order based on their sequence.

Stratigraphy Stratigraphy is the branch of geology that deals with the arrangement of rocks in layers.

The Geologist as Detective Chapter 6 : Interpreting Geologic History.

Relative Time: Ages of events are placed in order of occurrence. No exact date is identified.  Ex. WWI and WWII  Ex. I am the second child in my family.

A Little Bit of History … The history of geologic time begins with the human interest in mining. Interests in rock units began to flourish with commercial.

relative time vs. absolute time

GEOLOGICAL TIME. GEOLOGY NEEDS A TIME SCALE An investigation of the history of Earth Understanding how features of landscape developed and formed Reconstructing.

Geologic History Relative Dating. Birth of Modern Geology Began in the late 1700’s when James Hutton published his Theory of the Earth. He was the first.

Earth’s History How do we know about it?. What is Uniformitarianism? Uniformitarianism: –Is a theory developed by the Scottish geologist, James Hutton,

Geologist interpret Earth’s history by studying sedimentary rocks Relative Dating.

May 13, 2014 Open up your ISN. Call the next available left side page #84. Title the page “Vocabulary”. Call the following page #85. Title the page “The.

Uniformitarianism: the processes that act on the Earth’s surface today are the same as the processes that have acted on the Earth’s surface in the past.

Geologic Time. Rocks Record Earth History Rocks record geological events and changing life forms of the past. We have learned that Earth is much older.

The Rock Record Section 1 Section 1: Determining Relative Age Preview Objectives Uniformitarianism Relative Age Law of Superposition Principle of Original.

Relative-Age Dating. Scientists have not always thought Earth was as old as it is. James Hutton in the late 1700’s was the first geologist to think Earth.

Dating the Earth Chapter 12. A major goal of Geology is to interpret Earth’s History !! A pioneering geologist and 2 nd director of the USGS. Led an expedition.

Earth Science Notes Relative Age of Rocks. Objectives I can… Distinguish relative and absolute dating. Describe the 6 laws of relative dating. Use the.

Interpreting Earth’s Rocks to Determine Its Past History.

Earth’s History Introduction: The earth is about 4.6 billion years old. Much of its history is recorded in the rock. Observations of fossils, rock types,

The Rock and Fossil Record II. Relative Dating: Which Came First?

Relative Dating: Which Came First?

Geologic time Relative dating

21.2 – Relative Age Dating. Interpreting Geology James Hutton, a Scottish geologist who lived in the late 1700s Attempted to explain Earth ’ s history.

Discovering Earth’s History

Earth History- Table of Contents

Relative age dating Earth is very old (4.6 billion years old) and has changed over geologic time The rock record provides evidence of geological events.

The Rock Record.

EARTH’S HISTORY Relative Dating.

Geologic Time Uniformitarianism vs. Catastrophism.

Relative Dating.

Discovering Earth’s History

The History of Earth Relative Dating Absolute Dating

Interpreting Earth’s Rocks to Determine Its Past History

The History of Earth Relative Dating Absolute Dating

Geologic History Relative Dating.

How Old is Old? Geologic Time.

Relative Dating.

Chapter 8 section 1 RELATIVE AGE.

Ch. 13 Section 2 Relative Ages of Rocks.

Presentation transcript:

Interpreting Earth’s Rocks to Determine Its Past History

Geologic Time Relative Time - sequence of geologic events in a region (order of past events) Absolute Time – numeric- time in years; use radioactive isotopes. How do we know how old something is?

James Hutton: The father of modern geology ( ) Uniformitarianism: “The present is the key to the past.”

Examples of uniformitarianism Petoskey stones and past climates How sandstone forms Grand Canyon formation Dino reconstruction

Determining Geologic History: Geologists are like CSI detectives wanting to know Where?, When?, Why?, How? Sometimes very little “evidence” remains (exposure, erosion) Evidence has been moved or tampered with! Rocks have been moved (faults, folds) Usually no witnesses!

Principle of Superposition Oldest layer on bottom (if tectonically undisturbed) Younger Older

The Grand Canyon

Principle of Original Horizontality Sediments are originally deposited as horizontal (or near horizontal) beds- use with folded layers.

folded rock layers = compression by tectonic activity

Cross-Cutting Relationships An igneous intrusion (or fault) is younger than the rock layers that it cuts across. fault oldest These are younger than the surrounding rock youngest

Write the order of events that have taken place above. List (oldest - 1 to youngest - 6)

Which came first? A C B D E Order the rock layers above from oldest to youngest. Is this an example of absolute or relative dating?

Which came first? The first layer deposited and the oldest is D, followed by C, A, B, and E. D D D C C A B B E

List the order of events that took place: earthquake deposit D deposit B deposit G intrusive lava rocky deposit R river cuts through deposit E deposit A

Unconformities = “Missing Time”

Angular Unconformities Folded layers below horizontal layers. angular unconformity ( rock layers have been eroded away) rock layers are eroded new horizontal layers are deposited

FEDCBA Angular Unconformity sedimentary rocks above and below unconformity surface with rocks below tilted at an angle

The Great Unconformity – Grand Canyon, AZ

Granite sedimentary rock layers Cambrian Precambrian Nonconformity – younger sedimentary rocks rest on older igneous rocks

Nonconformity

Disconformity DISCONFORMITY:Missing rock layers (sedimentary) Very hard to pick out

Disconformities

Siccar Point, Scotland

granite sandstone shale limestone

Resources Bend%20National%20Park%20-%20Syncline%20-%20Javalina%20Creek%20- %2020%20June% jpghttp:// 20Bend%20National%20Park%20-%20Syncline%20-%20Javalina%20Creek%20- %2020%20June% jpg class.unl.edu/geol101i/images/igneous%20images/Black%20Canyon%20Gunnison.jpghttp://www- class.unl.edu/geol101i/images/igneous%20images/Black%20Canyon%20Gunnison.jpg