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Questions and Answers
Which geologic era is characterized by an age of approximately 541 million years ago?
Which geologic era is characterized by an age of approximately 541 million years ago?
What is the age of the Mesozoic era in millions of years?
What is the age of the Mesozoic era in millions of years?
Which statement about Albert Heim is correct?
Which statement about Albert Heim is correct?
How many years ago did the Quaternary period begin?
How many years ago did the Quaternary period begin?
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Which event is most likely associated with coral reefs found at high altitudes?
Which event is most likely associated with coral reefs found at high altitudes?
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Custom mineral and rock identification kits are being sold for how much?
Custom mineral and rock identification kits are being sold for how much?
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If UBC-Okanagan was separated from the continent, what geological process would this imply?
If UBC-Okanagan was separated from the continent, what geological process would this imply?
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What is the ending time for the L1B lab on Fridays?
What is the ending time for the L1B lab on Fridays?
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What principle suggests that current geological processes are similar to those that have occurred throughout geologic time?
What principle suggests that current geological processes are similar to those that have occurred throughout geologic time?
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Which statement best reflects James Hutton's view on Earth's age compared to prevailing theories of his time?
Which statement best reflects James Hutton's view on Earth's age compared to prevailing theories of his time?
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What was the date and time proposed by Archbishop Usher for the creation of the Earth?
What was the date and time proposed by Archbishop Usher for the creation of the Earth?
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What did Charles Lyell challenge about the theories regarding Earth's age?
What did Charles Lyell challenge about the theories regarding Earth's age?
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Which of the following concepts is directly related to the ability to infer ancient environments from present-day processes?
Which of the following concepts is directly related to the ability to infer ancient environments from present-day processes?
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Why did Hutton disagree with existing theories about sedimentary rock formation?
Why did Hutton disagree with existing theories about sedimentary rock formation?
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Which geological principle is tied to the idea that past geologic events can be explained by observable forces today?
Which geological principle is tied to the idea that past geologic events can be explained by observable forces today?
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What is the significance of the phrase 'The present is the key to the past' in geology?
What is the significance of the phrase 'The present is the key to the past' in geology?
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What is indicated by the presence of potash in Saskatchewan and oil in Alberta?
What is indicated by the presence of potash in Saskatchewan and oil in Alberta?
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What is the significance of geological time when interpreting current geologic processes?
What is the significance of geological time when interpreting current geologic processes?
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Which statement best describes relative dating methods?
Which statement best describes relative dating methods?
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What is the main focus of the scientific method?
What is the main focus of the scientific method?
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How did catastrophism explain Earth's surface features in the 18th century?
How did catastrophism explain Earth's surface features in the 18th century?
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What does the concept of half-life relate to in geological dating?
What does the concept of half-life relate to in geological dating?
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What is a primary aim when applying geological time concepts at an engineering project site?
What is a primary aim when applying geological time concepts at an engineering project site?
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Which of the following correctly describes a function of the geologic timescale?
Which of the following correctly describes a function of the geologic timescale?
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What does the Principle of Original Horizontality state about sedimentary rocks?
What does the Principle of Original Horizontality state about sedimentary rocks?
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Which principle indicates that the rock layers above another are younger?
Which principle indicates that the rock layers above another are younger?
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What does the Principle of Lateral Continuity suggest about rock units?
What does the Principle of Lateral Continuity suggest about rock units?
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Which geological unit's features suggest it is younger than the surrounding rocks?
Which geological unit's features suggest it is younger than the surrounding rocks?
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What did Lyell conclude when studying Mount Etna?
What did Lyell conclude when studying Mount Etna?
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Which geological principle states that if sedimentary rocks are folded, they were altered after deposition?
Which geological principle states that if sedimentary rocks are folded, they were altered after deposition?
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Under what condition can rock units be linked across distances according to the Principle of Lateral Continuity?
Under what condition can rock units be linked across distances according to the Principle of Lateral Continuity?
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Which principle describes that faults are younger than the rocks they intersect?
Which principle describes that faults are younger than the rocks they intersect?
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Which isotopic system is most suitable for dating archaeological artifacts?
Which isotopic system is most suitable for dating archaeological artifacts?
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What is the half-life of the Rubidium-Strontium isotopic system?
What is the half-life of the Rubidium-Strontium isotopic system?
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Which isotopic system has the shortest half-life?
Which isotopic system has the shortest half-life?
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What is the approximate age of the Earth based on meteorite dating?
What is the approximate age of the Earth based on meteorite dating?
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Which of the following isotopes is NOT mentioned as a viable dating method in the content?
Which of the following isotopes is NOT mentioned as a viable dating method in the content?
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To determine the age of a mineral/rock, which ratio is essential?
To determine the age of a mineral/rock, which ratio is essential?
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Why is the Carbon - Nitrogen isotopic system suitable for age-dating artifacts?
Why is the Carbon - Nitrogen isotopic system suitable for age-dating artifacts?
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Study Notes
Announcements
- There is an optional Mineral & Rock ID Kit available for purchase for $40
- Labs begin this week
- Office hours are Wednesdays 2-3 PM in EOSM 323
- Students can schedule additional time for office hours during the week
Lecture Goals - Geologic Time
- There are four main lecture goals in understanding Geologic time
- The geologic processes we see today are the same processes that shaped Earth's past.
- How to apply relative dating to interpret the geologic history of an engineering project site.
- Differentiate between relative and absolute dating methods.
- Describe the major divisions of the geologic timescale.
The Scientific Method
- A method to understand knowledge.
- The scientific method is a process of inquiry
- Hypothesis:
- An explanation that accounts for a set of observations and can be tested by further investigation.
History of Geology
- Catastrophism explains geologic features like mountains and valleys using disasters such as floods and earthquakes.
- The Catastrophism theory was used to explain the mysterious "funny looking bones" found in rock.
- The "funny looking bones" were linked back to religious doctrine like the Flood story and Noah's Ark.
- A popular theory during the 18th Century, Archbishop Usher's declared in 1658 that the Earth was begat on Sunday, October 23, 4004 B.C. at precisely 6:00 a.m.
- Uniformitarianism is the key to understanding how to study geology
- The principle is that geological processes operating now
- are the same processes that acted in the past.
- Past geologic events can be explained
- by forces observable today.
- By studying current events we can infer what paleo-environments existed in the past.
- James Hutton (1726-1797) championed Uniformitarianism.
- He used a concept called "The present is the key to the past."
Uniformitarianism - a study of geologic Processes
- Sedimentary rocks form over time, but the prevailing belief during the 18th Century was that the Earth was only 6,000 years old.
- Charles Lyell (1797 – 1875) disagreed with that theory and believed the Earth was much older.
- Lyell went on to study Mount Etna in Sicily, where he realized that the 3000 m volcano must have grown from thousands of small eruptions over several millennia.
- Lyell discovered fossil-rich limestone underneath Etna.
- Mount Etna must be younger than the limestone!! because of this discovery, Lyell felt strongly that the Earth was far older than originally believed.
Relative Time and Dating.
- A method of estimating an age of an object/event relative to other objects/events in the same sequence.
- Based on the order of events to understand a relative age.
- For example: Layer 1 is below Layer 2, so Layer 1 is older than Layer 2
Relative Dating Principles
- There is a theory called the Principle of Original Horizontality
- This theory states that sedimentary rocks are deposited horizontally due to gravity.
- If the rocks are folded, the folding occurred after they were deposited.
- There is also a theory called the Principle of Superposition
- This theory states that in a sequence of bedded rock, the layer above is younger than the layer below.
- Another relative dating principle is called Cross- Cutting Relationships.
- This theory states that faults and intrusions are younger than the rocks that they cut through.
- The last of the relative dating principles is called Lateral Continuity
- This principle states that rock units with similar characteristics can be correlated over large distances.
- This correlation can be aided by using fossil assemblages.
Absolute Dating
- Absolute dating uses radioactive decay in minerals to determine the age of rocks and minerals.
- The idea behind absolute dating is that radioactive isotopes decay at a constant rate.
- Scientists can determine the age of a rock by measuring the ratio of parent isotope to daughter isotope.
Examples of Radioactive Isotopes
- There are a few different common radiometric dating systems that are used to determine the age of rocks and minerals, including:
- Uranium-Lead
- Potassium-Argon
- Rubidium-Strontium
- Carbon-Nitrogen
- For example, carbon-dating is used to date ancient fossils and artifacts.
- Using a radioactive dating system scientists can determine the half-life of the isotope. The half-life is the amount of time it takes for half of the parent isotope to decay into the daughter isotope.
Half-Life
- The half-life of an isotope system is the time it takes for half of the parent isotope to decay into the daughter isotope.
- For example, if the half-life of a radioactive isotope is 2000 years, then after 2000 years, half of the parent isotope will have decayed into the daughter isotope. After another 2000 years, half of the remaining daughter isotope will have decayed, and so on.
The Age of the Earth
- By using radiometric dating methods, scientists have determined that rocks from meteorites and the moon are approximately 4.55 billion years old.
- This age is consistent with the age of the Earth, as the Earth formed from the same material.
Summary
- Geology uses several tools to determine the age of rocks and minerals, using both relative and absolute dating.
- Relative dating uses the order of events to determine the age of an object or event.
- Absolute dating uses radioactive decay to determine the age of an object or event.
- By understanding the principles of geologic time we can better understand the Earth's history and learn more about its evolution.
- These lessons can assist us in managing our resources, mitigating risks, and understanding the Earth's potential for the future.
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Description
This quiz covers essential concepts in geology including the principles of geologic time, methods of dating, and the scientific method used in geological investigations. Students will explore the connections between present geologic processes and Earth's history, as well as the distinctions between relative and absolute dating techniques.
