We know it’s BIG…but HOW do we know that?

Slides:



Advertisements
Similar presentations
Relative dating.
Advertisements

Relative and Absolute Age Law of Superposition
Relative Dating of Rocks Layers
“How can scientists determine the age of rocks and fossils?”
GEOLOGIC HISTORY THE RULES OF THE GAME
Using the rock record to age date rock layers
Relative Dating of Rocks
1) What is uniformitarianism?
Time and Geology. Relative Age Dating In trying to understand the creation of the geology of an area prior to the 20 th century techniques, a method referred.
Relative Age Dating Activity.
FINDING RELATIVE AGE. What is relative age?  1. The age of a rock compared to the ages of other rocks.  Absolute age-the EXACT age of rock (add to your.
Determining the Age of Rocks Relative Age of Rocks.
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.
GEOLOGIC HISTORY THE RULES OF THE GAME
Unit 5: Age of the Earth Objective:
Relative Dating The Law of Superposition
Relative Time.
Chapter 29 Studying the Past Paleontology Fossils Let’s talk about the types……… The study of life that existed in prehistoric times Preserved remains of.
Geologic Time Earth’s History.
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.
The Changing Earth. Understanding Earth Absolute dating - is the process of determining an approximate computed age in archaeology and geology. provides.
UNIT 5: GEOLOGIC HISTORY. AT THE END OF THIS UNIT YOU WILL BE ABLE TO  Calculate the absolute age of a substance based on its decay rate  Correlate.
Earth History- Table of Contents RELATIVE vs. ABSOLUTE LAWS UNCONFORMITIES GEOLOGIC SECTIONS.
Geology Review Game Ready your Mind!. Your teams are your table groups.
1 Earth’s History Planet Earth is approximately 4.6 billion years old –Rocks of the crust provide clues to Earth’s past By analyzing these clues we can.
Aim Aim: How do we know the age of the Earth? I. Earth’s History Uniformitarianism A. Uniformitarianism – the principle that most of the geologic events.
Define the following terms at the top of your notes for Ch 21!
Geological Time Geology 12. Uniformitarianism “The present is the key to the past”- the fundamental principle that underlies most of geology. Put simply,
SI. A) Relative age: the age of rock compared to the ages of other rocks above or below it in a sequence of rock layers.
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.
Understanding Geologic Time. How old is it? How do we know? Absolute dating – process of assigning a precise numerical age to an organism, object or.
Determining Geologic Time  Many geologic events that Earth Scientists study occurred millions of years ago. The ages of these events can be determined.
Relative Age dating Basic Principles.
Methods of Measurement
2 Types.  Relative Dating  Absolute Dating  1. Law of superposition – youngest layer on top; oldest layer on bottom.
Laws of Geologic History. Law of Superposition The oldest layer is at the bottom and the youngest layer is at the top. The oldest layer is at the bottom.
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.
Unit 3 Review Please see pages in your book for more information *This study guide is just to get you started studying– please look at your notes.
Earth’s History How do we know about it?. What is Uniformitarianism? Uniformitarianism: –Is a theory developed by the Scottish geologist, James Hutton,
Relative Dating. Relative Dating is one of the methods that geologists use to help tell geologic time. It can NOT tell us exactly how old something is,
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.
GEOLOGIC HISTORY, FOSSILS, & RELATIVE DATING. Geologic History  Uniformitarianism  The idea that the same geologic processes that are shaping Earth.
Earth Science Notes Relative Age of Rocks. Objectives I can… Distinguish relative and absolute dating. Describe the 6 laws of relative dating. Use the.
The Fundamental Laws of Geology Several principles or “laws” are fundamental to the geologic interpretation of a sequence of events.
Fossils Fossils are the remains, impression, or other evidence preserved in rock of the existence of life Fossils can be preserved as: –Molds –Casts –Original.
Aim: How do we determine the relative age of rock strata? Do Now: Clear your desk except for your Earth Science Reference Table.
The Law of Superposition Any method of determining whether an event or object is older or younger than another event. Comparing rock layers or fossils.
GEOLOGIC HISTORY THE RULES OF THE GAME
Determining the Age of Rocks
How is relative age dating like a hamper of clothes?
Relative Age Dating What is it?
Relative Age dating Basic Principles.
Relative Dating.
Relative Dating.
Principle of Original Horizontality
Relative Vs. Absolute Dating of Rocks
Geologic History Relative Dating.
How Old is Old? Geologic Time.
Relative Dating 12/7/2018.
GEOLOGIC HISTORY THE RULES OF THE GAME
Relative Dating.
Geologic Time.
Relative Age.
Relative Age The age of a rock unit or event relative to the age of another rock unit or event. In other words which layer or event came first, second,
Principles of Relative Age Dating
Geologic Time Notes By studying the characteristics of rocks and the fossils within them geologists can… interpret the environments in which the rocks.
GEOLOGIC HISTORY, FOSSILS, & RELATIVE DATING
Earth’s History Created by Educational Technology Network
GEOLOGIC HISTORY THE RULES OF THE GAME
How do we determine the age of rock layers?
Presentation transcript:

We know it’s BIG…but HOW do we know that? Geologic Time We know it’s BIG…but HOW do we know that?

BIG QUESTIONS: What methods do we use to figure out the age of our earth? How do fossils help us to learn things about the past?

Uniformitarianism Uniformitarianism is the assumption that the same processes that operate on the earth now have always operated on the earth in the past. For example: Given a long period of time, a river can erode a valley. Based on the principle of uniformitarianism, all valleys in the past have been formed by rivers eroding them and all future valleys will be formed this same way

Relative Dating Relative dating refers to the relative order in which things occurred, without knowing the actual date of each event. Relative dating relies on several principles.

Principle of Original Horizontality This principle states that layers of sediment are originally deposited horizontally under the action of gravity. This means that any “sloping” of layers must have occurred AFTER the layers formed

Principle of Superposition Layers of earth are deposited in a time sequence, with the oldest on the bottom and the youngest on the top.

Cross-Cutting Relationships  The principle of cross-cutting relationships states that the geologic feature which cuts another is the younger of the two features. Younger

Inclusions This principle states that fragments included in a host rock are older than the host rock itself. This rock (inclusion) must have existed BEFORE the lava (host rock) formed…therefore it is older.

Practice… Identify the layers from oldest to youngest

Absolute Dating Absolute dating refers to the exact age in years of an object Several methods exist for absolute dating.

Radiometric Dating Technique used to date materials such as rocks, using radioactive materials contained in the rocks/fossils This exact age can then help us with some aspects of relative dating

Fossils The preserved remains or traces of animals, plants, and other organisms from the past Many fossils can be dated using relative AND absolute dating

Index Fossils A particular plant/animal that only existed for a very short period of time on the earth Useful for relative dating purposes.